33. Bacteriology 💢 Flashcards

Question

What is the route of infection of Campylobacter and Salmonella?

Answer 1

Ingestion of undercooked poultry

Answer 2

* Adhesion and invasion factors * Type IV secretion system * Toxin

Answer 3

Young children (0-4 years)

Answer 4

Type III secretion system NOTE: Salmonella sp. can cause outbreaks whereas Campylobacter tends to be sporadic cases

Answer 5

* Cholera toxin * Type IV secretion system * Fimbria

Answer 6

* It has A and B subunits * A is the active toxin * B allows entry of the toxin into the epithelial cell * The **A subunit activates adenylate cyclase**, thus increasing the production of **cAMP** * The cAMP then binds to **CFTR** and causes **Cl- efflux** * Water follows the ion movement so you get massive movement of water into the lumen of the intestine

Answer 7

Immunocompromised Elderly Pregnant and their foetus

Answer 8

They can enter non-phagocytic cells and cross tight barriers (e.g. BBB and maternal-foetal barrier)

Answer 9

* Q fever * Plague * Yersinia pestis

Answer 10

1. Diphtheria 2. Invasive pneumococcal infections 3. Invasive meningococcal infections 4. Pertussis 5. Tetanus I 6. Invasive Haemophilus influenzae 7. Rabies Measles \* Mumps\* Rubella\* Polio\*

Answer 11

* **a. Antimicrobial** * Interferes with growth and reproduction of a microbe * **b. Antibacterial** * Commonly used to describe agents that reduce or eliminate harmful bacteria * **c. Antibiotic** * Type of antimicrobial that is used as medicine for humans and animals

Answer 12

Infections that occur after exposure to healthcare Infection starts \>48 hours after admission to hospital

Answer 13

They increase the length of stay at hospital

Answer 14

* Catheterisation * Intubation * Lines (e.g. central venous lines) * Chemotherapy * Prosthetic material

Answer 15

Dissemination by healthcare staff Concentration of ill patients

Answer 16

* Enterococcus faecium * Staphylococcus aureus * Clostridium difficile * Acinetobacter baumanii * Pseudomonas aeruginosa * Enterobacteriaceae * ESC are Gram-positive * APE are Gram-negative

Answer 17

They are antibiotic resistant

Answer 18

Cephalosporins

Answer 19

Carbapenems

Answer 20

* **a) Cephalosporins** * Target: * Penicillin binding proteins (PBP) * Resistance: * Extended-Spectrum Beta-Lactamase (ESBL) * **b. Carbapenems** * Target: * PBP * Resistance: * Carbapenemase enzymes * **c. Methicillin** * Target: * PBP * Resistance: * alternative target (PBP2A) * which has low affinity for methicillin and can function in its presence * **d. Vancomycin** * Target: peptidoglycan precursor * Resistance: synthesis of a different peptidoglycan precursor

Answer 21

Transposon

Answer 22

* UTI * Respiratory tract

Answer 23

Immunocompromised

Answer 24

* Cephalosporins, fluoroquinolones and aminoglycosides * Carbapenem resistance in the US

Answer 25

Immunocompromised

Answer 26

Carbapenems

Answer 27

Vancomycin NOTE: causes blood stream infections

Answer 28

Infections that occur after exposure to healthcare Infection starts \>48 hours after admission to hospital

Answer 29

Vancomycin NOTE: causes blood stream infections

Answer 30

Carbapenems

Answer 31

Immunocompromised

Answer 32

Cephalosporins, fluoroquinolones and aminoglycosides Carbapenem resistance in the US

Answer 33

Immunocompromised

Answer 34

* UTI * Respiratory tract

Answer 35

Transposon

Answer 36

* **a. Cephalosporins** * Target: Penicillin binding proteins (PBP) * Resistance: Extended-Spectrum Beta-Lactamase (ESBL) * **b. Carbapenems** * Target: PBP * Resistance: Carbapenemase enzymes * **c. Methicillin** * Target: PBP * Resistance: alternative target (PBP2A), which has low affinity for methicillin and can function in its presence * **d. Vancomycin** * Target: peptidoglycan precursor * Resistance: synthesis of a different peptidoglycan precursor

Answer 37

Carbapenems

Answer 38

Cephalosporins

Answer 39

They are antibiotic resistant

Answer 40

Enterococcus faecium Staphylococcus aureus Clostridium difficile Acinetobacter baumanii Pseudomonas aeruginosa Enterobacteriaceae NOTE: ESC are Gram-positive APE are Gram-negative

Answer 41

Dissemination by healthcare staff Concentration of ill patients

Answer 42

Catheterisation Intubation Lines (e.g. central venous lines) Chemotherapy Prosthetic material

Answer 43

They increase the length of stay at hospital

Answer 44

* **a. Gram positive bacteria** * Thick peptidoglycan cell wall * **b. Gram negative bacteria** * Outer membrane that contains lipopolysaccharide (LPS) * **c. Mycolic bacteria** * Outer mycolic acid layer

Answer 45

* A type of topoisomerase (topoisomerase II) * It releases tension in DNA and is important in unwinding DNA to allow protein binding required for DNA replication

Answer 46

Produces RNA from a DNA template

Answer 47

Eukaryote = 40S + 60S Prokaryote = 30S + 50S

Answer 48

* **Sulphonamides** – inhibits dihydropterate synthase * **Trimethoprim** – inhibits DHF reductase

Answer 49

Co-trimoxazole

Answer 50

Fluoroquinolones (e.g. ciprofloxacin) inhibits bacterial DNA gyrase and topoisomerase IV

Answer 51

Rifamycins (e.g. rifampicin) – inhibits RNA polymerase

Answer 52

* Macrolides * Aminoglycosides * Chloramphenicol * Tetracyclines

Answer 53

* A pentapeptide is created on **N-acetyl muramic acid (NAM)** * **N-acetyl glucosamine (NAG)** associates with **NAM** forming **peptidoglycan** * The peptidoglycan is then transported into the cell wall by **bactoprenol** * The peptidoglycan is then incorporated into the cell wall by **transpeptidase enzyme**, which cross-links the peptidoglycan pentapeptides

Answer 54

* Glycopeptides (e.g. vancomycin) – they bind to the pentapeptides and inhibit peptidoglycan synthesis * This is used as a last resort for Gram-positive bacteria that are resistant to other antibiotics

Answer 55

**Bacitracin** – this inhibits **bactoprenol**, hence preventing peptidoglycan transport

Answer 56

Beta lactams – they bind covalently to transpeptidase, which inhibits peptidoglycan incorporation into the cell wall

Answer 57

* Carbapenems * Cephalosporins * Penicillins

Answer 58

* Lipopeptides – disrupt Gram-positive cell walls * Polymyxins – bind to lipopolysaccharide and disrupt Gram-negative cell membranes

Answer 59

* **Additional target** * the bacteria produce another target that is unaffected by the drug * **Hyperproduction** * the bacteria increase the production of the target so the antibiotics are less effective (this is energy inefficient) * **Altered target site** * there is an alteration in the drug target so that the drug is no longer effective * **Alteration in drug permeation** * down regulation of aquaporins (responsible for allowing drugs into cells) or the upregulation of efflux systems * **Production of destruction enzymes** * beta-lactamases hydrolyse the C-N bond in the beta-lactam ring rendering the beta-lactams inactive

Answer 60

Gram-positive bacteria

Answer 61

Flucloxacillin and temocillin

Answer 62

* Amoxicillin (no antibiotic resistance on its own) * Clavulanic acid (beta-lactmase inhibitor)

Answer 63

* **Isoniazid** – inhibits mycolic acid synthesis * **Rifampicin** – inhibits RNA polymerase

Answer 64

Because of the peptidoglycan cell wall, which is impermeable so it retains the blue stain.

Answer 65

Beta: hemolyze fully Alpha: incomplete hemolysis, turn green (viridans). gamma: Don't hemolyze at all

Answer 66

staph: cluster like grapes strep: chains or diclocci (pair up), don't clump like staph

Answer 67

gray pseudo membrane

Answer 68

gram + = purple gram - = red

Answer 69

bacillus= rod shaped coccus = sphere shaped spirillum = spiral streptococci -\> cocci in chains staphylococci -\> cocci in clusters

Answer 70

-staph aureus -staph epidermis (foreign bodies - cath, prosthetic valve) -staph saprophyticus (UTIs)

Answer 71

It is bright yellow on sheep blood agar, and will coagulate positive with hydrogen peroxide (bubbles) this differentiates it from the other 2 staph species that are negative coagulants.

Answer 72

Strep. pyogenes (group A) strep. agalactiae (group B) strep. pneumoniae (pneumococcus) -\> GPdiplococci strep viridans Enterococcus (group D)

Answer 73

Because it is encapsulated so when you have no spleen you are at high risk for strep pneumo infections (also why immunocompromised, children, and elderly are at risk). -\> this doesn't have lancefield antigens either

Answer 74

differentiates between the different groups of streptococci species. All have specific antigens -\> group A, B Viridans (alpha hemo) and pneumo don't have lancefield antigens

Answer 75

skin (staph), soft tissue and bone

Answer 76

local: face -\> acne generalized (systemic)

Answer 77

the organism enters the body and reaches the target site of infection -\> then adheres to or enters host cells and multiplies at site of infection. Infection spreads within site (resp. tract or intestines). -the sxs of the illness appear - organism doesn't spread through the lymphatic system or reach the bloodstream. The infection subsides due to host defenses (immunity) -\> the agent is eliminated from the body and the infected cells are replaced and pt is cured!!

Answer 78

the organism enters the body and reaches the target site of initial infection. The organism then adheres to or enters the host cells and multiplies at initial site of infection. The infection spreads within the site and to other sites via tissues, lymphatic system, bloodstream (bacterimia, viremia) and possibly other routes. -sxs of illness may appear -organisms infect other organs, tissues and cells -\> more spread via bloodstream - sxs of illness become severe -host defenses eliminate organisms leading to cure or disease continues, possibly leading to irreversible damage or death.

Answer 79

cellulitis, and erysipelas

Answer 80

-necrotizing fasciitis (flesh eating) -myonecrosis (gas gangrene or clostridial myonecrosis) -pyomyositis (abscess from bacterial infection of skeletal muscles)

Answer 81

gram positive cocci, grape like clusters most are harmless and reside normally on the skin and mucous membranes MRSA: resistant to b-lactam antibiotics

Answer 82

a spider bite

Answer 83

coagulase + species (virulence) -\> staph aureus (common nasal flora) coagulase - species - staph epidermidis (universal skin flora)

Answer 84

stye (cordeolum) boils, carbuncles, furuncles sinusitis hematogenous spread (IV -epid.) endocarditis pneumonia, emesis, impetigo, diarrhea, TSS, UTI, cystitis, osteomyelitis, SSSS

Answer 85

folliculitis (boils), furuncles, burns and wounds

Answer 86

osteomyelitis, abscesses, pneumonia, endocarditis, septicemia

Answer 87

-staphylococcal scalded skin syndrome (SSSS), TSS, food poisoning

Answer 88

Most common in immunocompetent host -abscesses (cutaneous -\> common) -folliculitis -mastitis -wound infections - infect. IV catheter sites

Answer 89

bacteremia, septicemia, endocarditis, pneumonia, musculoskeletal: septic arthritis (injury)

Answer 90

HA-MRSA: health care assod, occur in people that have been in hospitals. Usually assod with invasive procedures or devices CA-MRSA: community associated among healthy people. Can begin as a painful skin boil. Spread by skin-skin contact, At risk pop: high school wrestlers, child care workers, and people who live in crowded conditions

Answer 91

generally start as small red areas that resemble spider bites, boils, pimples that can quickly develop into deep, painful abscess that require surgical draining (Really rapid -\> in 24 hours will progress) Sometimes will go deeper into tissue and cause life threatening infections in the bones, joints, blood stream, heart valves and lungs

Answer 92

culture and sensitivity - septra or -Doxy

Answer 93

Bactroban -\> ointment in nose qd full body wash -Hibiclens: rule of 3: 3x a day for 3 days then 3 x a week for 3 weeks

Answer 94

Group A strep cellulitis: follows an innocuous or unrecognized injury, inflammation is diffuse, spreading along tissue planes Staph aureus: usually assod w/ wound or penetrating trauma, localized abscess become surrounded by cellulitis

Answer 95

Don't use Keflex -\> doesn't cover MRSA -now half of cellulitis infections are resistant to tx with kefex -Current tx: clindamycin, doxycycline, Bactrim, Septra

Answer 96

Bactrim alt: clindamycin (sulfa allergy) Vanco: MRSA severe cellulitis: IV abx especially if pt has high fever and appears ill - be aggressive with tx!

Answer 97

animal bite on pt's face or hand area of skin involvement \>50% of limb or torso, or \>10% of bod surface -coexisting morbidity (diabetes, Heart failure, renal failure, edema) -compromised host -need for IV Abx

Answer 98

when the tissue in the area of cellulitis turns to pus under the surface of the skin, the collection of pus is called an abscess -the pus is just dead, liquified tissue, billions of WBCs - the most common bacteria in the abscess is staph aureus - but many other bacteria can cause abscesses -The organisms kill the local cells resulting in the release of cytokines which trigger an inflammatory response which draws large numbers of WBCS -

Answer 99

empyemas -\> these are accumulations of pus in a preexisting rather than a newly formed anatomical cavity

Answer 100

superficial: skin and subcutaneous tissues -\> infections of the hand Infections of the head and neck: suppurative parotitis (acute infection of the parotid) -Deep seated infections: hepatic abscess/ splenic abscess/ sub-phrenic abscess/ rectal abscess

Answer 101

Only if you see that there is an obvious abscess - should be drained + abx maybe - if the abscess has a lot of cellulitis around it then an abx is probably needed. -Antibiotics can't penetrate w/o drainage so they need to be drained.

Answer 102

this is caused mostly from strep - it is when the bacteria in a cellulitis or abscess starts spreading quickly between the fat layer and the muscle underneath -necrotizing= living flesh to dead flesh - fasciitis means the infection is spreading along space b/t fat and muscle -the infection cuts off blood supply to the tissue above it and the tissue dies - the bacteria may also enter the bloodstream.

Answer 103

cut all the dead tissue out, and keep cutting until only living tissue is left. -do this over and over again until the infection stops spreading. -Antibiotics help but don't cure the infection -The open muscle needs to be tx like a burn with skin grafts - empiric abx to cover anaerobes, gram -, streptococci, and staph aureus -abx for min. of 3 weeks

Answer 104

Gas gangrene - pure clostridium perfringens infection -gas in gangrenous muscle group - incubation hours to days -local edema and pain accompanied by fever and tachycardia -discharge is sero-sanguinous, dirty, and foul, crunchy upon palpation

Answer 105

Pen G or chloramphenicol -surgical removal of infected muscle -watch out for diabetics -consider hyperbaric chamber

Answer 106

- mostly caused by staph aureus - a purulent bacterial infection of skeletal muscles which results in pus-filled abscess. - most common in tropical areas, temperate zones - mainly a disease of children 2-5 Tx: must be drained surgically and abx given for min. of 3 weeks

Answer 107

Gastroenteritis (food poisoning) TSS Toxic epidermal necrolysis (TEN) - this started as rxn to drug -\> SJS -\> TEN Staph scalded skin syndrome (SSSS)

Answer 108

also known as Ritter disease: causes by epidermolytic toxins produced by certain strains of staph. This toxin is distributed systemically and results in dissolution of keratinocyte attachments in only the upper layer of the epidermis. - Usually affects newborns and children, adults less affected b/c of improved renal fxn allows for clearance of toxins from the body (w/ renal failure = more susceptible)

Answer 109

Staph epidermidis is a major component of the skin flora. - it is common in nosocomial infections: device/implant associated infections -\> shunts, catheters, artificial heart valves, joints, pacemaker (anything foreign in the body) (endocarditis)

Answer 110

30 species of bacteria - gram + cocci in chains subdivided by ability to lyse RBCS: beta (complete lysis), alpha (partial lysis), gamma (no hemolysis)

Answer 111

acute streptococcus infection of the upper dermis and superficial lymphatics. Caused most by strep. pyogenes (group A Beta hemolytic ) -Rarely caused by beta hero of B, C, G group - pathogen enters through a break in the skin and eventually spreads to the dermis and subcutaneous layer - can remain superficial or become systemic

Answer 112

Varying degrees of skin or soft-tissue erythema, warmth, edema and pain -associated fever and leukocytosis -hx of trauma, abrasion, or skin ulceration Cellulitis has an ill-defined border that merge smoothy with adjacent skin, usually pinkish to red erysipelas: has an elevated and sharply demarcated border with a fiery-red appearance

Answer 113

local care: immobilization, elevation to reduce swelling, draw lines on areas to assess response to tx - 2 weeks of abx therapy: PCN or dicloxacillin

Answer 114

(pyoderma) -\> superficial lesions that break and form highly contagious crust, often occurs in epidemics in school children, bug bites, poor hygiene, and crowded living situations

Answer 115

Non bullous: strep Group A or it could be staph aureus - see in pre-school and young school age, very thin walled vesicle on erythematous base, transient, yellowish-brain crusts (thick Bullous (blister forming): staph aureus cause, all ages, bull: 1-2 cm, persist for 2-3 days, thin and flat, brownish crust, fluid filled

Answer 116

malnutrition, diabetes, immuno-compromised status

Answer 117

strep infection (pink eye, meningitis, endocarditis) - scarlet fever (strep pyogenes (group A): get strawberry tongue - urtricaria - erythema multiforme: usually follows an infection or drug exposure

Answer 118

usually dx by presentation - no cultures usually needed - first soak affected area in warm water or use wet compress to help remove overlying scabs - abx creams or ointments: bactroban AAA Fusidic acid cream AAA retapamulon ointment consider septra/bactrim if hx of MRSA

Answer 119

- cutaneous infections - pharyngitis (sore throat) - otitis media - sinusitis -pneumonia - streptococcal TSS Complications of GABHS: rheumatic fever glomerulonephritis

Answer 120

rheumatic fever: follows overt or subclinical pharyngitis in children, extensive valve damage possible, arthritis, chorea, fever acute glomerulonephritis: nephritis, increased BP, occasionally heart failure, can become chronic leading to kidney failure

Answer 121

red, beefy tonsils that are covered in exudate, strawberry tongue, petechiae Differential: mono

Answer 122

normal flora in lower GIT, female genital tract -pathogenicity: neonatal meningitis and sepsis and pneumonia meningitis in babies: won't eat, crabby -\> fever, vomiting: Emergency

Answer 123

gram + cocci in pairs: pneumonia, otitis media, sinusitis, meningitis Prevention: vaccination (capsular antigens) immunization!!! sxs of strep pneumonaie pneumonia -\> shaking, chills, rust colored sputum, consolidation in lungs

Answer 124

presence of a middle ear infection acute otitis media: occurrence of bacterial infection w/in the middle ear cavity otitis media w/ effusion: presence of non purulent fluid w/in middle ear cavity -\> have bulging, taut, inflexible TM (have effusion: add decongestant to abx -\> drain better) \*OM: is 2nd most common clinical problem in childhood after URI

Answer 125

peak incidence in 1st 2 years

Answer 126

more common in boys -lower socioeconomic status (smoking) -seasonal disease (peak in Jan, Feb) - corresponds to rhinovirus, RSV, influenza seasons ( secondary infection to virus, don't get good drainage from initial infection, immunity down)

Answer 127

young age, bottle feeding, drinking a bottle in bed, parental hx, sibling hx, second hand smoke, daycare

Answer 128

suppurative infection of middle ear cavity, common bacterial pathogens achieve access through blocked eustachian tube (infection, pharyngitis, pr hypertrophied adenoids) - air trapping -\> neg. pressure -\> bacterial reflux bacterial reflux + obstructed flow = effusion

Answer 129

strep. pneumo H. influenza Moraxella catarrhalis Group A strep staph aureus pseudomonas aeruginosa RSV assoc. w/ acute otitis media

Answer 130

sxs are often nonspecific: fever, irritability, poor feeding, otalgia, otorrhea, signs of common cold

Answer 131

erythematic, opaque (not translucent, bulging TM w/ loss of anatomic landmarks including a dull/absent light reflex otoscopy: decreased tympanic membrane motility (pulled tight)

Answer 132

hearing loss, acute mastoiditis, chronic perforation of TM, tympanosclerosis, cholesteatoma, chronic suppurative OM, cholesterol granuloma: blue drum syndrome, facial nerve paralysis even worse: intracranial complications, bacterial meningitis, epidural abscess, brain abscess, subdural empyema, otitic hydrocephalus, lateral sinus thrombosis

Answer 133

infants 102) observation period is an option

Answer 134

amoxicillin for 10-14 days or augmentin + auralgan (analgesic/adjunct for ear pain -\> drops) TID

Answer 135

cefzil (2nd gen cephalosporin) 6 months to 12 years pediazole (erythro/sulfisoxazole) bactrim \*used as secondary agents if the pt is allergic to pcn or primary abx has failed after 10 days and sxs persist

Answer 136

alpha or gamma hemolytic -common oral/pharyngeal flora (bind to teeth, cavities) infections: endocarditis, bacteremia, and septic shock

Answer 137

-UTI -endocarditis -intraabdominal infections (abscesses) -biliary tract infections -wound infections \*resistant to vanco and ampicillin, even becoming resistant to aminoglycosides

Answer 138

- culture - ASO titers/streptozyme (body will develop abs to strep -\> streptolysin O) - rapid Group A strep tests -gram stains antistreptolysin O (ASO) titer is a blood test to measure abs against streptolysin O, a substance produced by group A streptococcus bacteria

Answer 139

S. pyogenes: PCN (low incidence of resistant organisms S. pneumoniae: increased PCN resistance Erythromycin for both in PCN allergic pt Ampicillin for enterococcus

Answer 140

gram positive spore forming bacterium Bacillus anthracis (special capsule to avoid phagocytosis) - anthrax spores are easily found in nature, and can be produced in the lab, can last a long time in the environment - anthrax has been used before as bioterrorism agent - can be released into powders, sprays, food and water - primarily disease of herbivores which are infected by ingesting spores in the soil -natural transmission to humans by contact with infected animals or contaminated animal products

Answer 141

reservoir: herbivores (cattle, goats, sheep), capable of surviving in enviro for prolonged periods Transmission: contact, ingestion, or inhalation of infective spores sources of infection: contaminated hides, wool, hair, bone, meat, or other animal products

Answer 142

incubation period: 1-7 days (1-60 days) - clinical syndromes: cutaneous ulcer, respiratory, gi, oropharyngeal - inhalation anthrax= main threat spores may germinate up to 60 days after exposure - bronchopneumonia not a component -\> hemorrhagic lymphadenitis and mediastinitis - hard to early dx

Answer 143

stays local, necrotic center

Answer 144

epidemiology: sudden appearance of multiple cases of severe flu illnesses with fulminant course and high mortality non-specific prodrome of flu-like sxs -possible brief interim improvement -abrupt onset of resp failure and hemodynamic collapse 2-4 days after initial sxs, possible accompanied by thoracic edema and widened mediastinum on CxR (from bleeding)

Answer 145

dx studies: chest radiograph w/ widened mediastinum, periph blood smear w/ gm + bacilli on unspun smear Micro: blood culture growth of large gm + bacilli with preliminary identification of Bacillus sp. patho: hemorrhagic medistinitis (death), hemorrhagic thoracic lymphadenitis, hemorrhagic meningitis

Answer 146

prophylaxis: pre-exposure: vaccine (not available?) post exposure: cipro or other quinolone or doxy (vaccine if available) CDC isolation: standard contact isolation if cutaneous lesions present

Answer 147

prophylaxis: cipro or doxy x 60 days tx for cutaneous: cipro or doxy x 60 days tx for inhalation: cipro or doxy plus vanco, imipenem (initial rx= IV then switch to PO for total 60 days) same tx for children and pregos

Answer 148

gram + rod -acute bacterial respiratory infxn caused by Corynebacterium diphtheria -may involve any mucous membrane: will see gray pseudomembrane - classified based on site of infection (laryngeal, cutaneous, ocular, genital) -very rare in 1st world countries

Answer 149

myocarditis and neuritis - death occurs in 5-10% from respiratory disease

Answer 150

sxs: sore throat, malaise, cervical lymphadenopathy, and low grade fever - earliest pharyngeal finding is mild erythema, which can progress to isolated spots of gray and white exudate. In 1/3 of pts - elaboration of toxin induces formation of coalescing pseudomembrane. This membrane adheres tightly to underlying tissue and bleeds with scraping but doesn't scrape off.

Answer 151

abxs: erythro or PCN G diphtheria antitoxin for severe cases - careful airway management -serial electrocardiograms and cardiac enzymes - neuro status should also be monitored carefully

Answer 152

Gram-negative

Answer 153

Neisseria meningitidis Influenza Parainfluenza Streptococcus pneumoniae Streptococcus pyogenes Staphylococcus aureus

Answer 154

E. coli Klebsiella Candida

Answer 155

Chlamydia Syphillis Neisseria gonorrheae

Answer 156

Staphylococcus aureus Streptococcus pyogenes

Answer 157

Abscess formation Bacteraemia Necrotic infection

Answer 158

Vibrio cholera Salmonella Listeria Shigella E. coli Campylobacter jejuni

Answer 159

Diarrhoea Bacteraemia/systemic infections

Answer 160

Infectivity and Virulence

Answer 161

The ability of a pathogen to establish infection

Answer 162

The ability of a pathogen to cause disease

Answer 163

Number of bacteria needed to cause infection

Answer 164

It uses its flagella to propel itself into the mucosal membrane of the intestines. It then begins producing toxins A and B, which bind to GM gangliosides and triggers production of cAMP This leads to chloride efflux and hence movement of water into the lumen from the cells

Answer 165

Shigella - negative Streptococcus - positive Listeria - positive Clostridium - positive Vibrio cholerae - negative E. coli - negative Salmonella - negative Staphylococcus - positive Neisseria - negative Haemophilus influenzae - negative

Answer 166

Pseudomonas aeruginosa Acinetobacter baumanii

Answer 167

E. faecalis Staphylococcus epidermidis

Answer 168

Gram-negative bacteria have a thin peptidoglycan layer with two membranes (cytoplasmic and outer membranes) Gram-positive bacteria have a thick peptidoglycan layer, which retains the dye well. It only has one membrane

Answer 169

E. coli – diarrhoea, dysentery, kidney failure Salmonella - food poisoning, typhoid Shigella – dysentery Neisseria – meningitis + gonorrhoea Vibrio cholerae - cholera

Answer 170

Lipopolysaccharide

Answer 171

Staphylococcus aureus – skin infections, endocarditis, bacteraemia, pneumonia Streptococcus pneumoniae – pneumonia, meningitis, otitis media Streptococcus pyogenes – tonsillitis, necrotising fasciitis, scarlet fever

Answer 172

Mycobacterium tuberculosis – TB Mycobacterius leprae - leprosy

Answer 173

Intracellular and Extracellular pathogens

Answer 174

Staphylococcus Streptococcus Neisseria Yersinia

Answer 175

Escape Preventing fusion with lysosome Surviving in the phagolysosome

Answer 176

Escape – Listeria, Shigella Prevent fusion of lysosome – Salmonella, Mycobacteria, Chlamydia Survive in phagolysosome - Coxiella

Answer 177

Flagella Type III Secretion system

Answer 178

A protein machine assembles which provides a channel through which virulence proteins can be injected into the host cell The virulence proteins then stimulate actin polymerisation and membrane ruffling which allows bacterial internalisation Gram-positive bacteria don’t have the type III secretion system

Answer 179

Bacteria (such as listeria and shigella) can polymerise actin at one pole of the bacterium forming comet tails This polymerisation propels the bacterium through the cytoplasm

Answer 180

Transformation, Transduction and Conjugation

Answer 181

Transformation – the uptake of naked DNA from the environment Transduction – bacteriophages infect a bacterium and take up some of the bacterial DNA. The bacteriophage then carries the bacterial DNA to another bacterium. Conjugation – transfer of genetic material in the form of a plasmid via a conjugation tube

Answer 182

Horizontally acquired genes that contribute to the virulence

Answer 183

- confirm a dx - exclude a dx - screening - monitor the course of a disease - monitor response to therapy - stage the severity of the disease - provide a prognosis

Answer 184

- Collection methods: swab, aspirate, expectorant - physiologic variables transient bacteremia - meds: especially abx

Answer 185

- as a general rule: infection considered if \>10^5 organisms found -

Answer 186

1 full day to grow the organism and then part or all of 1 day to ID it. It may take an add. day to isolate it b/f ID if there is a mix of organisms. - a preliminary report for most cultures may be issued in 24 hours

Answer 187

- normal flora from the infection - normal flora and pathogens vary dependent on anatomic location

Answer 188

staph epiermidis, S. aureus, micrococcus, few gram - bacilli moist skin, corynebacterium, propionibacterium acnes

Answer 189

strep. pyogenes pseudomonas proteus

Answer 190

strep pneumoniae, strep pyogenes, Neisseria meningitidis, H. influenza, N. gonorrheae

Answer 191

potentials: mycoplasma, bordatella pertussis, many others pathogens: staph aureus, pseudomonas

Answer 192

corynebacterium, Neisseria, moraxellae, staph, strep, occasional Haemophilus and parainfluenza

Answer 193

pneumococcus, pseudomonas, strep

Answer 194

C. diff, salmonella, toxic strains of E. coli, Helicobactor pylori (in duodenum)

Answer 195

chlamydia, gonorrhea, syphilis

Answer 196

- varies with hormonal state

Answer 197

candida, trichomonas

Answer 198

- obtain specimen before abx - use strict aseptic technique - minimize contamination by skin and mucous membranes (be careful with swabbing) - collect an adequate volume and send tissue or fluid rather then a swab when possible (culture when possible) - label appropriately - fill out requisition slips completely and precisely - call microbio dept if you have any ???s

Answer 199

within 1-2 hours of collection, but if delay is unavoidable most specimens (except blood, CSF

Answer 200

blood cultures: 48-96 hours most routine cultures (urine, throat, sputum): 24-48 hrs unless looking for unusual bacteria - anaerobes: can take 48-72 hours \* almost always get gram stain with culture in most settings

Answer 201

-routine: blood agar -chocolate agar -\> gram negatives (GC & Haemophilus) -anaerobic blood agar: needs to be fresh -sabourad agar: fungi - GPS -\> gram + selective media -\> allows isolation of strep and staph and inhibits most gram - rods - MacConkey or eosin methylene blue agars: anaerobic gram - rods - Thioglycollate media: liquid media, enrichment broth used as supplement to plated media

Answer 202

- usually pus present - round up some pus on an applicator - culture of specimens from the skin edge is less accurate than culturing the suppurative material - if anaerobic organism suspected -\> get anaerobic culturette from lab

Answer 203

- incised and any fluid or material swabbed with culture swab and sent to lab - important to get pus/exudate from deep in the wound to avoid surface contamination

Answer 204

- gently swab to collect drainage - place in approp. container and send to lab at 25 degrees C

Answer 205

- done to rule out strep pharyngitis (GABS) - sore throat, inflamed tonsils - inform lab if trying to ID something else such as N. gonorrheae (this reqrs Thayer-Martin agar) - swab posterior pharynx and tonsils - avoid touching any other part of mouth - send to lab at 25 degrees C - often indicated if the in office rapid strep screen is negative

Answer 206

-HAP - hosp patients with pneumonia (CAP) and any of the following criteria: -ICU admission - failure of output abx therapy - cavitary lesion - active alcohol use (aspiration pneumonia) - severe obstructive of structural lung disease - + urine antigen test for pneumococcus - + urine antigen test for Legionella - pleural effusion

Answer 207

- for most outpatient CAPs - management of bronchitis - initial management of acute exacerbations of COPD

Answer 208

- obtain prior to abx tx - have the pt rinse their mouth prior to expectoration - no food 1-2 hours prior to expectoration - inoculation of culture media immediately after specimen is obtained or immediately after prompt transport to microbio lab - bronchoscopy: sampling of lower airway is another potential dx method in patients w/ suspected pneumonia

Answer 209

- may be inaccurate due to mouth flora - suspect a pathogen if WBCs are present along with an overabundance pf 1 type of organism -first morning sputum will represent deeper pulmonary secretions - induce cough with nebs, pulmonary PT, aspiration, bronchoscopy

Answer 210

- always get a gram stain too! - helpful for directing empiric therapy

Answer 211

The sputum will contain abundant PMNs and few or no organism will be seen on the gram stain

Answer 212

abundant inflammatory cells and gram + diplococci

Answer 213

- bacteremia - septicemia - unexplained post operative shock - unexplained fever of several days duration - pneumonia - chills and fever in pts with: infected burns or UTIs rapidly progressing tissue infections post-op wound sepsis indwelling venous or arterial catheters -debilitated pts receiving: abx, corticosteroids, immunosuppressives, parenteral hyperalimentation (nutrition)

Answer 214

- should mainly be considered in pts w/ temp \>101 suspected of having endocarditis or other systemic pathogens - std of care for inpatients w/ pneumonia prior to starting abx - can repeat in 1 hour or if fever (transient bacteremia) - 2 specimens obtained from 2 separate sites 15 minutes apart (aerobic or anaerobic?) - # of organisms / site is low - helps id contaminants - total: 30-40 ml of blood

Answer 215

- clean site first with 70% alcohol - follow with butadiene x 2 minutes - wipe bottle tops with alcohol - go to lab immediately - don't draw blood cultures through central lines or IV (contamination)

Answer 216

- clean catch, mid void specimen - collect 5-50 ml of urine - cath -suprapubic tap \*best culture is in the morning (most concentrated)

Answer 217

- midstream clean catch urine by pt - need at least 1 ml - transport a 4 degrees centigrade - straight cath specimen: same parameters - indwelling cath: disinfect port with alcohol remove 5-10 ml of urine w/ needle and syringe -\> transfer to sterile container, 4 C - suprapubic aspirate: at least 1 ml, at 4 C - always send as UA and urine C & S

Answer 218

- pH - specific gravity - bilirubin - protein (nephritis -\> elderly) - glucose -\> diabetics - ketones (diabetic ketoacidosis) - blood: can't always rely on - nitrate: certain bacteria - leukocyte esterase (pyuria)

Answer 219

leukocyte esterase: if + on dipstick likely indicates pyuria nitrite: indicates the presence of enterobacteriaceae that converts nitrate to nitrite if neg but + symptoms of UTI still want urine culture

Answer 220

- eval of urine sediment from a spun sample - presence of squamous epithelial cells = contamination from genital region - normals: rbc: 0-5 HPF wbc: 0-5 HPF bacteria: absent casts: 0-4 hyaline LPF (kidney health) crystals

Answer 221

- look for blood (possible subarachnoid hemorrhage) - find the organism causing the meningitis or brain abscess - can do gram stain early on while awaiting culture reports - cell and chemistry counts will aid in making the dx

Answer 222

- suspected meningitis, high fever in infant - lumbar puncture collect 1-5 ml of CSF - transport at 25 degrees C - gram stain and bacterial culture - 4 tubes for: cell count, glucose and protein, gram stain and culture, and cell count to compare to tube 1

Answer 223

- thoracentesis - dx and/or therapeutic: therapeutic- relieves dyspnea (breathe easier) diagnostic: test the fluid for TB, CEA level (tumor marker), cytology, culture, gram stain, pH

Answer 224

- over because nerves and vasculature along bottom of ribs

Answer 225

- swollen joint - infection, inflammation or uric acid -meds shouldn't be administered therapeutically at the same time because interfere with sample (corticosteroids, abx)

Answer 226

- peritoneal, pericardial, pleural, synovial - aspirate using sterile technique into sterile syringe (usually pt has fever or elevated WBCs) - remove needle and cap syringe to send to lab, sometimes put aspirate in a different container - min. of 1-10 cc, send as much fluid as possible - send at 4 degrees C

Answer 227

- swab cervix for gonorrhea, chlamydia as well as other organisms in suspected PID - swabs of urethra or urine testing for chlamydia - occasionally swabs of vagina are done

Answer 228

- no douching or tub bathing for 24 hours prior to collection - swab -\> checking for gonorrhea, chlamydia

Answer 229

- helpful in evaluating vaginitis - saline wet mount of vaginal discharge can show epithelial cells covered with bacteria suggestive of bacterial vaginosis - trichomonads - can reveal multiple PMN's - KOH (K+ hydroxide) wet mount can reveal candida organisms

Answer 230

- special smaller swabs for urethral sampling for gonorrhea and chlamydia and other less common infectious agents - urine samples for GC and chlamydia for nucleic acid amplification - nucleic acid amplification more sensitive than culture

Answer 231

- usually on men - culture for GC, chlamydia - rapid enzyme test available - Thayer martin/New York media - anaerobic transport

Answer 232

- routine culture (for those with prolonged diarrhea or haven't been on abx or hospitalized) - \>2 grams, 4 degrees C - C. diff toxin: test of choice for those who develop diarrhea on abx or in hospital \> 3 days - \>5 ml, 4 degrees C

Answer 233

- also check for ova & parasites - usually look for staph, salmonella, shigella - Don't mix urine or TP with sample - rectal swabs: worms - 'tape test'

Answer 234

- acute cough: only exists for less than 3 weeks and is most commonly due to an acute respiratory tract infection. Other considerations include and acute exacerbation of underlying chronic pulmonary disease, pneumonia, and PE - Chronic: cough that has been present longer than 3 weeks is either subacute (3-8 weeks) or chronic (more than 8 weeks)

Answer 235

- post nasal drip from allergies or chronic sinusitis - asthma - postinfectious - chronic bronchitis - GE reflux - heart failure - medication induced (ACE inhibitors) - enviro irritants -\> pollution

Answer 236

- Mycobacterium TB - Mycobacterium Leprae - Atypical & nontubercular mycobacterium

Answer 237

- an infectious disease caused by the tubercle bacillus, Mycobacterium tb, and characterized pathologically by inflammatory infiltrations, formation of tubercles, caseation, necrosis, abscesses, fibrosis and calcification - most commonly affects the respiratory system

Answer 238

- Acid fast bacilli stain mycelia acid which makes up the wall of mycobacterium take up acid fast stain (won't show up in gram - or + stains)

Answer 239

- TB is one of world's deadliest disease: 1/3 of world's pop is infected with TB - each year over 9 mill people around the world are afflicted with TB - each year, almost 2 mill TB related deaths worldwide - TB is leading killer of individuals who have HIV -Incidences of TB in the U.S\> has been decreasing. Increase in 1992 (18% increase compared to 1985) associated with HIV

Answer 240

- yes, the TB rate has been going down in U.S. each year since 1992 - the average annual % decline in the TB rate slowed from 6.6% for 1993 through 2002, to an avg decline of 3.4% for 2003 - 2008 - rate from 2013: 3.2%

Answer 241

- HIV patients account for 30-50% of increase - HIV is the greatest known RF for reactivating latent TB infection

Answer 242

- prevalent in populations co-infected with HIV and M. tuberculosis, such as inner city minority and injection drug users - in some inner city tb clinics: 40% of all pts with TB are infected with HIV - TB in foreign born individuals accounted for 53% of cases in 2004 (mexico, philippines, Vietnam, India and China)

Answer 243

1. immediate clearance of the organism 2. chronic or latent infection (gets past initial immunity barriers into lungs) 3. Rapidly progressive disease (primary disease -\> rapidly spreads throughout lungs, may spread to other organs) 4. Active disease many years after the infection (reactivation disease) may lay dormant for many years

Answer 244

- person comes in with positive PPD but is asymptomatic with clear CXR - Person is infected but not infectious

Answer 245

1. small bacilli carried in droplets small enough to reach alveolar space 2. If host system fails in clearing: - Bacilli proliferate inside alveolar macrophages and kill the cells - infected macrophages produce cytokines and chemokines that attract other phagocytic cells, including monocytes, other alveolar macrophages, and neutrophils, which eventually form a nodular granulomatous structure called the tubercle or Gohn focus - if the bacterial replication isn't controlled, the tubercle enlarges and the bacilli enter the local draining lymph nodes, this leads to lymphadenopathy, a characteristic manifestation of primary TB - Caseation/fibrosis/calcification: ghon complex (caseation: necrosis of cells (look like cheese in middle of complex) - calcification is imp step in containing bacterium

Answer 246

1. bacilli reach alveolar space 2. proliferation inside macrophages 3. initial inflammatory granulomatous tubercle formation (if bacterial replication is controlled here, pt will not develop primary disease and is said to have chronic or latent infection) 4. Enlargement of tubercle and infiltration of lymph system (Gohn complex: describes an inflammatory nodule in the pulmonary parenchyma (Gohn focus) with an accompanying hilar adenopathy, in line with lymphatic drainage from the pulmonary segment

Answer 247

- those who develop active disease w/in 2-3 years after infection - sever illness: lung necrosis, and extrapulmonary involvement

Answer 248

Central: appetite loss, and fatigue lungs: chest pain, coughing up blood, productive and prolonged cough Skin: night sweats, pallor (anemia from chronic disease)

Answer 249

1. asymptomatic primary infection occurs 2. cell-mediated immunity: has contained the infection (neutrophils, macrophages -\> gohn complex probably present) 3. dormancy 4. then, recurrence may occur

Answer 250

- results when the persistent bacteria in a host suddenly proliferate (no longer contained b/c decreased immunity) - clearly assoc. with immunosuppression and can be seen in the following circumstances: HIV infection and AIDs end stage renal disease diabetes mellitus malignant lymphoma corticosteroid use \* in contrast to primary disease: the disease process in reactivation TB tends to be localized, there is little regional lymph node involvement and the lesion typically occurs at the lung apices (where gohn lesion resided)

Answer 251

cough, hemoptysis persistent fever/night sweats wt loss malaise adenopathy pleuritic chest pain

Answer 252

- develops aneurysm and it ruptures

Answer 253

- if the bacterial growth continues to remain unchecked, the bacilli may spread hematogenously to produce disseminated TB - lung looks like it is covered with millet seeds -Miliary TB is used to denote all forms of progressive, widely disseminated hematogenous TB even if the classical pathologic or radiologic findings are absent

Answer 254

Acute (primary infection) - high fevers, night sweats, Occ. Resp. distress, septic shock, multigrain failure - acute tend to be young Chronic: reactivation TB - fever, anorexia, wt loss, particularly in the elderly (FTT)

Answer 255

- frequency is increasing - past hx is unreliable - 50% have normal chest radiographic findings - clinical features vary widely - most common type is infection of an individual organ system (bowel, bone, spleen, brain -\> depends on where disease is expressed in the body) -in most cases, same regimens used for pulmonary TB are used systems that can be effected: - pleural/pericardial effusions (can lead to pericardial constriction) - lymph node infection: tuberculous lymphadenitis -\> scrofula, seen in younger pts - kidney - skeletal: 35% -\> potts disease - joints - CNS tuberculosis: meningitis, intracranial tuberculoma (mass lesion on the brain), spinal tuberclous arachnoiditis (similar to meningitis, arachnoid specific) intraabdominal TB: GI tract, peritoneum, renal TB, testicular granuloma - TB retinitis - muscles: (ex: psoas)

Answer 256

dx in most cases are clinical - most persons dx w/ TB are begun on specific tx before dx is confirmed by the laboratory because it takes a long time to confirm dx - Around 15-20% of pts that are given a presumptive TB dx never have bacteriologic confirmation of disease

Answer 257

- has had exposure to TB infection

Answer 258

- Ziehl neelsen test - takes a long time to culture mycobacterium

Answer 259

- generally used as screening test, most sensitive test for dx of infection with mycobacterium TB - far more sensitive than a chest radiography - + TB skin test doesn't by itself prove the presence of active disease but does indicate that infection has occurred - negative reactions have been doc. in 20% of pts who have TB - Primary use in detection of Latent TB infection - testing is targeted in persons at high risk for developing symptomatic TB who would benefit by tx of LTBI or those pts at increased risk for primary TB should they acquire infection - test is discouraged in those at low risk

Answer 260

- must be done intradermally ( b/c confined area: protein derivative where T cells can get to) - Must form a visible wheal with injection (subcutaneous admin. will result in a false-neg. test if the pt indeed has been infected by TB)

Answer 261

- must be read 48-72 hours (reaction is from delayed type hypersensitivity response mediated by T lymphocytes) - test is read by the diameter of the induration, not the diameter of the erythema - finger vs ballpoint pen method

Answer 262

- HIV infection - ongoing close contact with cases of active TB: health care workers prison guards mycobacterial lab personnel Presence of medical condition that increases risk of active TB: DM, steroid therapy, other immunosuppressive agents, certain types of malignancies, end stage renal disease, alcoholism, suppressed immune systems - medically underserved, low income population: homeless, injection drug users - residence in long term care facility: nursing homes, correctional institutions, mental institutions - single potential exposure to TB ( dx of TB of family member): repeat testing in 6-12 weeks if pt tested shortly after exposure - presence of incidentally discovered fibrotic lung lesion - immigrants and refugees from countries with high prevalence of TB

Answer 263

- inadequate nutrition - anergy - nontubercular mycobacterium (bovus and avian) - simultaneous presence of immunosuppressive disorder - concurrent viral infection - corticosteroid therapy

Answer 264

- HIV positive persons - recent contacts of TB case - fibrotic changes on chest radiograph consistent with old TB - pts with organ transplants and other immunosuppressed pts ( receiving \>15 mg/d prednisone for \> 1 month)

Answer 265

- recent arrivals (10 %, gastrectomy, jejunolieal bypass - children

Answer 266

- persons with no RFs for TB

Answer 267

- children who received this vaccine generally demonstrate PPD reactions of 3-19 mm several months after vaccination - TB skin testing is not CI in BCG vaccinated persons: baseline testing should be done several months following vaccination - subsequent tests can be compared to baseline tests to eval. likelihood of true TB infection - responses indicative of new TB infection include: - increase in skin test reactivity \> 10 mm induration in persons less than 35 yo - increases in reactivity of \> 15 mm induration in persons greater than 35 yo \* if baseline values unavailable: reactivity should be interpreted and tx as for unvaccinated persons

Answer 268

- when active disease is suspected, there should be an exam of sputum for Acid Fast Bacilli staining and mycobacterium culturing - if pt unable to produce sputum spontaneously attempts should be made to induce sputum: hydration pulmonary physiotherapy mucolytic agents bronchoscopy or bronchoalveolar lavage \* impt test: gold standard dx test: culture bacilli

Answer 269

- Mycobacterium have a cell envelope, unlike gram - bacteria, there is no true outer membrane in mycobacterium, the envelope is composed of a number of different macromolecules including mycolic acid - AFB smear: makes presumptive dx of TB in high risk pt - not specific for Mycobacterium TB (other acid-fast organisms will be positive such as mycobacterium avium and bonus) - 2 versions: fluorchrome staining: decreases exam time and increases sensitivity versus Ziehl-Neelsen method but is expensive Ziehl Neelsen method (older)

Answer 270

- gold std of dx of TB - slow growth rate Solid media: lowenstein- Jensen or Middlebrook - takes up to 8 weeks or longer to detect growth Liquid media: expensive, broth formulations, more rapid and can detect growth of mycobacteria in clinical samples in as few as seven days

Answer 271

- whole blood interferon gamma assay (Quantiferon-TB Gold test) - screening test for asymptomatic disease - T cells of individuals previously sensitized with TB AGs will produce interferon gamma when they reencounter mycobacterial AGs - 99% accurate reading - can be used in all circumstances in which PPD is used (have negative PPD and have been exposed)

Answer 272

- subject to less testing error - subject to less reader bias and error - can be accomplished after a single pt visit - may not be as likely to be positive following BCG vaccination - The RD1 AGs used in this testing are not shared with most nontuberculous mycobacteria (bonus and avium)

Answer 273

-Can produce results within 2-7 hours after sputum processing - requires higher level labs - highly specific for Mycobacterium TB and is generally recommended on all AFB smear-positive respiratory specimens - + nucleic acid assay of AFB smear positive respiratory sample is dx of TB

Answer 274

- rod shaped bacteria with lipid rich cell walls - they grow very slowly and take a long time to eradicate with antibacterials

Answer 275

- 9 months of Isoniazid alt: Rifampin PO daily for 4 months

Answer 276

- requires at least 2 effective drugs b/c of increased incidence of drug resistance - Initial therapy of active TB include 4 drugs: - INH - RIF - Pyrazinamide (PZA) -Ehtambutol (EMB)

Answer 277

- covalently binds to and inhibits enzymes essential for synthesis of mycolic acid \* very specific to TB b/c of mycelia acid cell envelope - never used alone as resistant organisms will rapidly emerge AEs: hepatotoxicity: monitor liver enzymes - most common SE: peripheral neuritis which manifests as paresthesias and is assoc. with pyridoxine ( Vit B6) deficiency

Answer 278

- broader antimicrobial activity than INH - blocks transcription by interfering with the beta subunit of bacterial RNA polymerase - in add. to mycobacteria -\> effective against many gram + and - bacteria (frequently used prophylactically for individuals exposed to meningitis caused by meningococci or H. influenzae - AEs: hepatotoxicity, liver enzymes inducer of cytochrome P450 enzymes and therefore the pt may need higher dosage requirements for other drugs metabolized by this system

Answer 279

- unknown - only seen in anti tubercular combo packages - AE: extensively metabolized by liver, must watch for hepatotoxicity - gout

Answer 280

- inhibits an enzyme important for the synthesis of the mycobacterial arabinogalactan cell wall - AEs: optic neuritis: results in diminished visual acuity and loss of ability to discriminate from red and green - eye exams regularly (every couple of weeks)

Answer 281

- aminsalicylic acid - capreomycin - cylcoserine - ethionamide - fluoroquinolones\* - macrolides\* (used outside of TB tx)

Answer 282

- multi drug resistance: Isoniazid and Rifampin Extremely drug resistance: use Isoniazid, Rifampin, a fluoroquinolone, and injectable (amino glycoside) - requires ID specialist - 18-24 months tx - surgery often required

Answer 283

- b/c sxs are often gone w/in 2 months of initiating multi drug therapy yet the pt must continue therapy for 6 months - 2 years before organism is fully eradicated - TB occurs with a higher incidence in several pt populations that show higher noncompliance (injection drug users) -

Answer 284

DOT therapy: directly observed therapy - trained health care worker or other designated individual (excluding family member) provides the prescribed TB drugs and watches pt swallow every dose - nurse or supervised outreach worker from county public health dept can provide DOT

Answer 285

Penicillins, cephalosporins, monolactams, and carbapenems all have b-lactam ring in the center. Some of these are inactivated if the ring is cleaved by B-lactamases. monolactams and carbapenems are are reisistant to B-lactamases

Answer 286

Clavulanic acid binds and inhibits B-lactamase. - augmentin is trade name for amoxicillin and clavulanic acid. - Timentin is trade name for ticarcillin and clavulanic acid.

Answer 287

probenicid, it acts by competing with penicillin for the organic anion transport system which is primary route of penicillin excretion --\> results in higher levels of penicillin in the serum.

Answer 288

B-lactam binds PBPs and inhibits cross linking of bacterial cell wall components

Answer 289

Gram postive cocci -\> strep and staph gram positive rods --\> listeria and actinomyces gram neg cocci -\> Neisseria most mouth anaerobes (clostridium) \*\*\*Not effective against gm - aerobes or B lactase producing organisms w/o conjugative therapy - penicillinase sensitive dosage forms: IM, IV, PCN VK: oral (poor bioavailability)

Answer 290

nonresistant staph and strep, N. meningitidis, B. anthracis, C. tetani, C, perfingens, Listeria, syphillis

Answer 291

IV/IM for Penicillin G PO for Pen V Eliminated by kidneys

Answer 292

Hypersensitivity reactions, rare neurologic toxicity (seizures), Neutropenia, nephrotoxicity

Answer 293

bactericidal --\> bind to PBPs and inhibit transpeptidation which stops cross linking of polysaccharides and cell wall is destroyed and bacterial cell dies.

Answer 294

Penicillins, Cephalosporins, and B-lactamase inhibitors combined with PCN's

Answer 295

Penicillin G Antistaphlococcal PCNs: nafcillin, dicloxacillin, oxacillin, cloxacillin Broad spectrum PCNs: 2nd generation: ampicillin, amoxicillin 3rd generation: carbenicillin, ticarcillin 4th generation: piperacillin

Answer 296

amoxacillin/potassium clavulanate= augmentin (PO) ampicillin/sublactam=unasyn (IV) Ticarcillin/potassium clavulanate= timentin Piperacillin/tazobactam sodium= zosyn (sepsis)

Answer 297

All PCN's should be given on an empty stomach except oral amoxicillin Allergic rxns to one PCN are cross reactive to others, reactions can be urticarial to anaphylaxis to serum sickness All abs can cause C. diff colitis

Answer 298

IM forms: 1 injection lasts 10-12 days used for strep and sometimes syphillis, gonorrhea now is resistant IV form: meningitis and endocarditis

Answer 299

1-24 million units/day every 4-6 hours erysipelas: IV 1-2 million units q 4-6 hours x 7-10 days neurosyphilis: IV 18-24 million units q 4-6 hours x 10-14 days

Answer 300

Preg Cat: B -\> presumed safe lactation: safe Renal dosing: adj for creatine clearance adjust`

Answer 301

local: site reaction significant reactions: CNS -\> coma, seizure hematologic and oncologic: neutropenia, positive direct coombs test Hypersensitivity: anaphylaxis, reaction, serum sickness Renal: acute interstitial nephritis, renal tubular disease

Answer 302

BCG: used for TB - abx may diminish therapeutic effect of vaccine methotrexate: PCNs may increase serum conc of metho Probenecid: may increase serum conc of PCN Tetracycline derivatives: may diminish effect of PCNs Vit K antagonists (warfarin) - PCNs may enhance effect of Vit K antagonists -\> monitor INR OBCPs: pen may decrease OBCP efficacy

Answer 303

oral form -\> 250-500 mg TID-QID DOC for strep pharyngitis AE's: GI -\> N/V/D acute nephritis, convulsions, hemolytic anemia, positive coombs reaction

Answer 304

activity: semisynth PCNs used for infection with B-lactamase producing staph, also used against PCN susceptible strep and pneumococci \*\*inactive against enterococci and methicillin resistant strains

Answer 305

Dicloxacillin, oxacillin and nafcillin (not affected by beta-lactamase enzyme)

Answer 306

dicloxacillin: PO Oxacillin: IM, IV Nafcillin: IV

Answer 307

Preg Cat: B lactation: unknown No dosage adj needed for renal or hepatic disease

Answer 308

GI (dicloxacillin)-\> Nausea, diarrhea, abdominal pain agranulocytosis, eosinophilia, hemolytic anemia, hepatotoxicity

Answer 309

Aripiprazole: PCN may decrease concentration Ca channel blockers: Nafcillin may increase metabolism contraceptives: Nafcillin may increase metabolism of estrogens BCG: may diminish effects of BCG Methotrexate: may increase serum concentrations Probenecid: may increase PCN serum concentration Warfarin: may diminish effect

Answer 310

2nd gen: ampicillin, amoxicillin 3rd gen: carbenicillin, ticarcillin 4th gen: piperacillin

Answer 311

cover same as PCN G also E. coli, proteus marabilis, Salmonella, Shigella and H. influenzae, Amox is better absorbed uses: otitis, sinusitis, lower RTI Amox combined with clay acid will expand coverage to gm +, gm - and anaerobic organisms

Answer 312

Preg Cat: B, Lacation: safe Renal dosing: adjust if CrCl

Answer 313

CNS: agitation, anxiety, confusion, seizure Hematologic: agranulocytosis, anemia, eosinophilia, hemo anemia Renal: crystalluria

Answer 314

high % of patients have developed rash during therapy, don't use in these patients

Answer 315

Allopurinol: may enhance risk of hypersensitivity rxn of PCN BCG: diminish effect of BCG methotrexate: may increase metho coc tetracycline: may diminish effects of PCNs Warfarin: PCNs may enhance effect OCPs: PCNs may decrease efficacy

Answer 316

carbenicillin and ticarcillin activity: strep, enteric gram-neg bacilli (e. coli, klebsiella, pneumoniae, enterobacter cloacea, enterobacter aerogenes and proteus miriabilis), pseudomonas, and anaerobes - IV only: std therapy as anti-pseudomonal med in hosp.

Answer 317

derivative of ampicillin, covers same spectrum as 3rd generation, but more active against Klebsiella, enterococci and bacteroides \*\*piperacillin w/ tazobacatm (zosyn): broad spectrum, used for cellulitis, postpartem endometritis, peritonitis, comm-acquired pneumonia, nosocomial pneumonia

Answer 318

can cause bleeding problems can cause nephritis IN high doses can cause near complications and seizures - common to see secondary infections such as vaginal candidiasis

Answer 319

clavulanic acid, sublactam, tazobactam activity: inhibitors of many bacterial b-lactamases, inactivate ahminoglycosides Use: only in comb with PCN -\> PCN determines spectrum: -intra-abdominal/gynecological infections -skin and soft tissue infections RTI, sinusitis, and lung abcesses -Don't have any antimicrobial activity by themselves.

Answer 320

as they progress from 1st to 3rd generation they increase in gm - coverage and lose gram positive coverage. - well absorbed from GI tract, and food enhances absorption. - allergic reactions are similar to PCNs (3-10% cross-reactivity)

Answer 321

are susceptible to B-lactamases and they have similar SE's as penicillin.

Answer 322

1st: cephalexin (keflex), 2nd: cefaclor (ceclor), 3rd: cefixime (suprax)

Answer 323

cefadroxil=oldest, cephalexin= keflex cefazolin= Ancef (IV) activity: good against gram +: strep and staph (not MRSA), some gram -, good against anaerobic cocci SE: GI, allergic reactions, C. diff

Answer 324

cephalexin: uncomplicated cellulitis cefazolin: more complicated cellulitis or IV prophylaxis prior to surgery

Answer 325

cefaclor PO (more susceptible b-lactamase hydrolysis, not as useful), cefuroxime; IV, cefoxitin IV, cefotetan IV activity: gram +, better gram - against klebsiellae, H. influenza, none against pseudomonas

Answer 326

cefuroxime: sinusitis, otitis, RTI, comm acquired pneumonia (H. flu, K. pneumonia, and penicillin resistant pneumococci). cefoxitin: anaerobic activity- prophylactic GI surgeries, peritonitis, and diverticulitis (active against gm - rods)

Answer 327

cefotaxime IV, ceftazidime IV, ceftriaxone activity: expanded gram - against meningicoccus, citrobacter, b-lactamase strains of homophiles and neisseria ceftazidime- active against pseudomonas cefotaxime and ceftriaxone: cross blood/brain barrier

Answer 328

ceftriaxone and ceftotaxime: meningitis empirical therapy for serious infections -\> effective against PCN resistant strains pnemonococci ceftriaxone: used to tx gonorrhea, lyme disease SE: rash, N/V, LFTs, eosinophilia, HA

Answer 329

cefepime IV activity: gram + and -, including pseudomonas, staph aureus, strep pneuma, Haemphilus and Neisseria

Answer 330

penetrates BBB well -\> meningitis, other serious infections and sepsis sometimes used with amino glycoside w/ tx pseudomonas SE: N/V/D, HA, rash

Answer 331

1st gen: cephalexin and cefazolin still used a lot 2nd gen: tx otitis, sinusitis, and RTI (Ceftin) 3rd and 4th: DOC for gram - meningitis, good alt to aminogly. need to watch for resistance strains -\> combo therapy good for pseudomonas, Ceftriaxone: DOC for gonorrhea Ceftazidime: effective for pseudomonas meningitis

Answer 332

Imipenem/cilastatin - better coverage than meropenem (IV( activity: very resistant to cleavage (b-lactamase), effective against gram + (enterococcus faecalis, and listeria), gram - (H influenza, N gonorrhoaea, enterobacter, and pseudomonas), anaerobes (bactericides)

Answer 333

meropenem= meningitis, intra-abdominal infections, resistant UTIs, pseudomonas, and w/ or w/o aminoglyc for neutropenic pt SE: N/V/D, rashes, imipenem: renal failure and seizures

Answer 334

The concentration of antibiotic that can be achieved in a clinical setting If the bacteria can divide at a concentration at or higher than the breakpoint, it is deemed resistant

Answer 335

Pseudomonas aeruginosa Klebsiella Salmonella Acinetobacter baumanii Neisseria gonorrheae

Answer 336

Staphylococcus aureus (MRSA) Streptococcus pneumoniae Clostridium dificile Enterococcus spp. Mycobacterium tuberculosis

Answer 337

Beta-lactams Aminoglycosides Chloramphenicol Tetracycline Quinolones Sulphonamides Macrolides

Answer 338

Penicillin and Methicillin They have a beta-lactam ring that is a similar shape to a precursor of peptidoglycan in the bacterial cell wall and hence interferes with the synthesis of the cell wall

Answer 339

Quinolones inhibit the functioning of DNA gyrase (Gram-negative) and topoisomerase (Gram-positive) hence hampering the unravelling of DNA during replication

Answer 340

Only Gram-positive infections Targets the 50S ribosomal subunit and prevents the peptidyl transfer step Erythromycin

Answer 341

Aminoglycosides affect RNA proofreading leading to misfolded proteins Some of these proteins get incorporated into the membrane and cause leakage Gentamycin and Streptomycin

Answer 342

Inhibits the folate pathway

Answer 343

Prevents charged amino-acyl tRNAs from binding to the mRNA/ribosome complex

Answer 344

Inhibits the peptidyl transfer step Binds to the 50S subunit

Answer 345

Altered target site Inactivation of antibiotic Altered metabolism Decreased drug accumulation

Answer 346

nafcillin (IV) and dicloxacillin (PO) provide excellent coverage and are not destroyed by penicillinases (beta- lactamases) 1st gen Cephalosporins (cephalexin and cefazolin) are effective against most skin infections

Answer 347

3rd generation Cephalosporins are good, and not destroyed by cephalosporinases. They also penetrate CNS Cephalosporins and penicillins may enhance the activity of aminoglycosides against Gram - neg. Combo of Amp and Gent provides good coverage of both positive and negatives. Trimethoprim-sulfamethoxazole (Bactrim/Septra) is active against most UTI's. Amoxicillin is used for otitis media and other bact. URI's

Answer 348

Ticarcillin or ceftazidime cover most Gm neg including Pseudomonas but fail to tx some Gram positive Imipenem and meropenem good against pseudomonas

Answer 349

Metronidazole or clindamycin cover most mouth anaerobes are adequately coverage by penicillin

Answer 350

Macrolides (erythro, clarithro, azithro) tx mycoplasma pneumonia along with other organisms that cause community acquired pneumonia

Answer 351

Amphotericin is DOC for fungemia. (only for use in severe systemic infections)

Answer 352

abx that kill bacteria

Answer 353

only inhibit bacterial proliferation while host's immune system does the killing. (not very effective in immunocompromised patients: cancer, HIV, diabetes, or in overwhelming infections).

Answer 354

Have developed resistance to basic penicillins and some specialized penicillins Have a peptidoglycan cell wall that surrounds bacteria, makes the cell impermeable (unlike gm -), Will stain blue Effective tx: penicillins, cephalosporins, bacitracin, vanco, and cycloserine inhibit the synthesis of the peptidoglycan cell wall.

Answer 355

staph aureus and staph epidermidis: inhabit skin, most likely to infect wounds, surgical sites, and indwelling catheters Strep pneumo is often cause of community-acquired pneumonia and adult bact. meningitis Strep throat is caused by Group A beta-hemolytic Streptococcus (if left untx --\> cause rheumatic fever)

Answer 356

common anaerobes: Bacteroides fragile, C. diff, and Fusobacterium. C. botulinum and C. tetani produce toxins responsible for botulism and tetanus. Metronidazole, chloramphenicol or clindamycin are effective against anaerobic infections Appearance: mixed gm + and - compost of most anaerobic infections. Frequently are encased in abcess wall.

Answer 357

mouth, GI, and skin infections occur when anaerobes penetrate poorly oxygenated tissues (diabetic foot) or tissues that are normally sterile (peritoneum). C. diff flourishes in bowel when broad spectrum abx diminish normal flora. C. diff proliferates and releases a toxin that causes pseudomembranous colitis

Answer 358

1. enterics, organism that normally inhabit GI (escherichia, shigella, salmonella, klebsiella, enterobacter, Serrate, proteus). 2. H. influenzae 3. Neisseria 4. Pseudomonas

Answer 359

Enterics and H. influenzae are red and elongated Plasma membrane is protected by an adjacent rigid peptidoglycan cell wall which is encased by an outer membrane. This membrane is made of lipopolysaccharides interrupted by transmembrane protein pores (which prohibit entry of most penicillins and cephalosporins).

Answer 360

Depends, penicillins must first penetrate outer membrane in order to act on inner cell wall. Broad spectrum penicillins and 3rd gen cephalosporins are more hydrophilic and able to get through pores but even so some strains are resistant to penicillins b/c they produce B-lactamases that are concentrated in space between outer membrane and cell wall. Neisseria meningitides and N. gonorrhea are the only gm - that are susceptible to penicillin G and other narrow spectrum penicillins. \*ceftriaxone is DOC for N. gonorrhea due to resistant penicillin strains

Answer 361

Enterics responsible for UTIs and aspiration pneumonia N. gonorrhea is responsible for sexually transmitted gonorrhea N. menigitides and H. influenzae both cause meningitis H. influenza causes pneumonia more commonly in the elderly Pseudomonas aeruginosa is sometimes responsible for hospital acquired infections.

Answer 362

-susceptible organism -MOA -drug inhibits bacterial growth (bacteriostatic), or if it is lethal to cells (bacteriocidal)

Answer 363

narrow: active only against few microorganisms broad: active against a wide variety

Answer 364

Disruption of bacterial cell wall: penicillins, cephalosporins -\> act to weaken cell wall and thereby promote cell lysis inhibition of enzyme: sulfonamide drugs suppress bacterial growth by inhibiting enzyme required to produce folic acid from PABA. Disruption of bacterial protein synthesis: disrupt function of bacterial ribosomes Inhibition of bacterial nucleic acid synthesis

Answer 365

B-lactam abx: penicilllins, cephalosporins, carbapenems, monobactams - clavulanic acid, sulbactam, taxobactam

Answer 366

Aminoglycosides: gentamicin, tobramycin, amikacin Tetracyclines: tetracycline, doxycycline, minocycline

Answer 367

macrolides: erythromycin, clarithromycin, azithromycin others: chloramphenicol, clindamycin, linezolid, streptogramins

Answer 368

Fluoroquinolones: cipro, oflaxacin, norfloxacin, levofloxacin, gatiflocacin, moxifloxacin Metronidazole

Answer 369

sulfonamides, trimethoprim

Answer 370

GI tract: aids in digestion mucous membranes: mucosal immunity in general: protects host from colonization with pathogenic microbes

Answer 371

cause disease when immune defenses are altered, when they change their usual anatomic location -the blood, brain, muscle and CSF are normally free of flora

Answer 372

streptococci viridans Lactobacilli Staph (aureus and epidermidis) corynebacterium sp. bacteroides sp. streptococcus sanguis streptococcus mutans actinomyces sp.

Answer 373

staphylococcus epidermidis corynebacteria staph aureus Neisseria sp.\* Haemphilus sp\* strep pneumoniae\*

Answer 374

non-hemolytic strep alpha-hemolytic strep Neisseria sp. strep pneumoniae strep pyogenes H. influenzae Neisseria meningitidis

Answer 375

usually sterile individual becomes infected by the pathogen descending from the nasopharynx (H. influenzae, and S. pneumoniae)

Answer 376

staph epidermidis staph aureus corynebacterium sp.

Answer 377

Enterobacteriaceae enterococci bacteroides staph lactobacilli clostridia

Answer 378

staph epidermidis enterococcus faeccalis Alpha-hemolytic strep E coli proteus corynebaceria sp. acinetobacter sp. mycoplasma sp. candida sp mycobacterium smegmatis

Answer 379

corynebacterium sp. staph nonpyogenic strep (Group B) E coli lactobaciluus acidophilus flavobacterium sp. clostridium sp. viridans strep other enterobacteria

Answer 380

native valve: sterp viridans -\> Pen G or Amp+Nafcillin IV drug user: MSSA, MRSA -\> vanco Prosthetic valve: S. epi, S. aureus, S. viridans -\> vanco+rifampin+gentamicin

Answer 381

Diverticulitis, perirectal abscess, peritonitis-\> E. coli, p. aeruginosa, enterococci tx: TMP-SMX-DS or cipro, or levofloxacin+ metronidazole (outpt)

Answer 382

gen. cellulits: staph aureus, strep-\> MSSA: cephalexin, MRSA: TMP-SMX-DS or clindamycin strep: cephalexin diabetic ulcer: staph, strep or pyogenes-\> Doxy or TMP-SMX-DS or clindamycin Animal bites -\> cat: amox-clav (augmentin) Necrotizing fasciitis: GABS, C. perfringens -\> PCN G, cefoxitin, chloramphenicol, clindamycin, metronidazole

Answer 383

E. coli, gram - aerobic bacilli, enterococcus, staph saprophyticus -\> TMP-SMX-DS if resistance is \>20% to TMP -\> use cipro, levo, moxi

Answer 384

Aspiration pneumonia: anaerobic or aerobic -\> clindamycin or ampicillin-sulbactam or A carbapenem Lower/hosp acquired: pseudomonas aeruginosa, gram - aerobic bacilli -\> imipenem -cilastatin or meropenem + cipro if suspect pseudo Hx of HIV: pneuomocystis carinii, S. pneumoniae -\> Trimethoprim-sulfamethoxazole (Bactrim, Septra)

Answer 385

sinusitis: S. pneumo, H. influenzae, M. catarrhalis, S. auerus, Grp A strep --\> peds: amox or amox-clav, pcn allergy: clinda adult: amox-clav, pcn allergy: levo or doxy Community acquired pneumonia: all same as sinusitis plus klebsiella, mycoplasma, chlaymdia -\> azithro, clarithro, doxycycline

Answer 386

child ampicillin + gentamicin child 2 months - 12 years: strep pneuma, N. meningitis, H. influenza -\> vanco + cerfriaxone

Answer 387

1 mo -\> 50 years: S. pneumoniae, meningococci: cefotaxime or ceftriaxone+ vanco amp+cefotaxime or gentamycin

Answer 388

should be admin. before surgery begins via IV -often used to irrigate surgical site as well - Cefazolon (Ancef) 30 minutes before incision for pcn allergies: use vanco

Answer 389

prosthetic heart valves congenital heart disease

Answer 390

30-60 minutes prior to dental procedures: amoxicillin 2 gm PO if PCN allergy: clinda, azithro, clarithro

Answer 391

toxicity C. diff alt of gut flora and change of Vit K levels leading to difficulty managing warfarin therapy candida overgrowth serious side effects

Answer 392

can be life threatening, sever inflammation of colon, may lead to colectomy, highly contagious

Answer 393

Most frequent: Ampicillin/amoxicillin cephalosporins clindamycin quinolones

Answer 394

ciprofolxacin\* levofloxacin\* moxifloxacin\* gemifloxacin norfloxacin oflaxacin

Answer 395

-good tissue and fluids distribution except CNS -all undergo renal elimination except moxifloxacin -Half lives range from 4-12 hours (allows for 1/day dosing)

Answer 396

bactericidal - inhibit DNA gyrase and topoisomerase necessary for replication of bacteria

Answer 397

Aerobic gram neg: all fluoroquinolones Pseudomonas Aeroginosa: cipro or levofloxacin Gram + (including Strep pneumonia): levofloxacin, moxifloxacin, and gemfloxacin Anaerobic: moxifloxacin

Answer 398

Urinary tract= DOC -\> cipro -pneumonia -STIs -skin and soft tissue (not first line) -GI infections -Traveler's diarrhea -osteomyelitis (good penetration into bone)

Answer 399

Levofloxacin, moxifloxacin, and gemifloxacin

Answer 400

associated with an increased risk of tendinitis and tendon ruptures in all ages, risk is increased in older patients usually over 60 you, in patients taking corticosteroids, and pts with kidney, hearth or lung transplants

Answer 401

N/D, dizziness, confusion, tendon rupture, QT prolongation (ventricular tachycardia= death) tendonitis -\> RF for rupture, peripheral neuropathy (on long term therapy)

Answer 402

- ciprofloxacin potent inhibitor of CYP4501A2 -\> theophylline, warfarin, tizanidine, propranolol -antacids, sucrlafate, magnesium, calcium, iron all decrease the absorption of FQs -corticosteroids increase risk of tendon ruptures

Answer 403

if they are on moxifloxacin

Answer 404

Yes, contains the only oral agents against pseudomonas

Answer 405

not for use in pregnancy or children -\> in pregnancy and lactation= exposure to infant (crosses placental barrier) in peds= arthropathy and osteochondrosis - caution when using in hepatic dysfunction

Answer 406

sulfamethoxazole/Trimethoprim (SMX-TMP) (Bactrim DS, Septra)

Answer 407

oral med with good distribution to all body tissues and fluids -\> CSF, pleural fluid, synovial fluid -eliminated through liver and kidneys

Answer 408

Folic acid synthesis inhibitors: Bacteria need to produce folic acid to survive -\> SMX inhibits dihydropteroate syntheses and TMP inhibits dihydrofolate reductase

Answer 409

UTIs PCP (pneumonia seen in immunocompromised pts) toxoplasmosis Gram + and - infections MRSA (have resistance to strep pneumo)

Answer 410

\*\*Rash (very obvious it is sulfa related), fever, N/V/D, SJS (shed skin), vasculitis, hemolytic anemia if underlying G6PD deficiency, thrombocytopenia

Answer 411

cell death causes the dermis and epidermis to separate -hypersensitivity reaction of skin and mucous membranes

Answer 412

up to 70% protein bound -\> displaced other drugs potentiates the effects of: warfarin, phenytoin, hypoglycemic agents, methotrexate(folic acid inhibitor -\> together could cause folic def) B blockers: increase activity -\> severe bradycardia

Answer 413

metabolized in liver excreted renally -reduce dose by 50% if CrCl 15-30 not recommended if CrCl

Answer 414

due to development of kernicterus in infants (bilirubin induced brain dysfunction b/c of hemolytic anemia leads to increased bilirubin)

Answer 415

don't use with a sulfa allergy

Answer 416

only for treatment and prevention of uncomplicated UTIs PO

Answer 417

rabidly absorbed and only in serum for 30 minutes -cleared renally and concentrated in urine -inadequate drug levels in bladder if CrCl abnormal (GFR

Answer 418

thought to disrupt bacterial cell wall synthesis through inhibition of bacterial enzymes

Answer 419

E. coli Citrobacter Staph saprophyticus enterococus faecalis enterococcus faecium -some emerging resistance against enterobacter and Klebsiella

Answer 420

Most common: N/V pulmonary reactions: pulmonary infiltrates, pneumonitis, pulmonary fibrosis Hepatic effects (rare): hepatitis, hepatic necrosis peripheral neuropathy in long term use in patients with renal failure

Answer 421

-acute pulmonary reactions usually manifested by sudden, severe dyspnea, chills, chest pain, fever, and cough -pulmonary infiltration with consolidation or pleural effusion on radiographs and eosinophilia also may occur - usually evident within first week of tx and reversible when drug d/c -Resolution is often dramatic

Answer 422

No significant drug interactions because it isn't in plasma for more than 30 minutes -\> urinary tract

Answer 423

pregnancy: category B But CI at term due to possibility of causing hemolytic anemia in newborn -dont use in lactation -safety and efficacy not established in children

Answer 424

avoid use in older adults, avoid using for long term suppression of infection

Answer 425

Metronidazole (flagyl)

Answer 426

metabolized by the liver -adjust dose with hx of liver failure -absorbed well PO -good tissue penetration in most locations -Half life 6-9 hours

Answer 427

inhibitor of bacterial protein synthesis -\> causes DNA strand breakage therefore inhibiting bacterial protein synthesis

Answer 428

good against gram + and - anaerobes Helicobacter pylori Trichomonas vaginalis (STI in men and women)

Answer 429

Anerobic infections bacterial vaginosis trichomoniasis C. diff diarrhea

Answer 430

oral, IV, topical (roseacea), intravaginal

Answer 431

metronidazole has been shown to be carcinogenic in mice and rats. Unnecessary use of drug should be avoided.

Answer 432

most common: N/V, abdominal pain and metallic taste -seizures (high doses), -peripheral neuropathy (prolonged courses) -pancreatitis

Answer 433

enhances anticoag effects of warfarin -alcohol: flushing, palpitations, nausea, vomiting -inhibitor of CYP34A so potential for many drug interactions -phenobarbital, phenytoin, rifampin: all increase metabolism of metronidazole which decreases the serum concentration and may lead to tx failure

Answer 434

-- most common opportunistic infection assoc. with AIDS (very rarely does it occur outside of immunocompromised pts) -fever, cough, SOB (hypoxia: w/o PO2

Answer 435

- CXR: cornerstone of dx see diffuse or perihelia infiltrates -Wright-Giemsa stain or direct fluorescence AB (DNA) test on induced sputum - bronchoalveolar lavage - Elevated lactase dehydrogenase (LDH): occurs in 95% of cases

Answer 436

- continued until CD4 count is above levels used to initiate tx - hx of infection: continue until they have had a durable virologic response to HAART for at least 3-6 months and maintain CD4 count \>250

Answer 437

- increased incidence of pneumothorax, especially with hx of PCP and tx with aerosolized pentamidine

Answer 438

- R/O disseminated first if symptomatic - meningeal involvement is most common form of disseminated disease dx: blood cultures will be positive if disseminated

Answer 439

- spiking fevers - night sweats - diarrhea - wt loss - wasting - anemia and neutropenia - meningeal signs

Answer 440

- when CD4 is less than 50

Answer 441

- should be initiated with CD4

Answer 442

- Moritz Kaposi: 1872 - 4 subtypes - classic K.S. - middle aged men of mediterranean descent - African endemic K.S. - in iatrogenically immunosupressed pts - AIDS related K.S.(most common form seen in U.S.)

Answer 443

- may appear anywhere: most often on face and legs, palate, eyelids, conjunctiva, pinnae, toe webs - look purplish, will be NONBLANCHING, may be papular or nodular, appear more brown in dark skinned people, they are not painful

Answer 444

- Dermatological Kaposi's isn't life threatening - but may progress to visceral disease in about 40% of patients with derm. K.S., thus becoming life-threatening.

Answer 445

- abdominal pain - diarrhea - intestinal obstruction

Answer 446

-swelling of arms or legs

Answer 447

- cough, chest pain, SOB, difficulty breathing, extremity swelling, pulmonary blockage (alveoli or vascular system in lungs)

Answer 448

- w/ contained skin lesions, tx may not be necessary. Lesions that involve large areas of skin or internal organs, tx is recommended. Tx include: topical meds, surgical removal, freezing with liquid nitrogen, chemo drugs

Answer 449

- chemotherapy has proven effective - unpleasant SEs as N/V and hair loss - drugs can have damaging affects on the heart and bone marrow, resulting in decrease in number of white blood cells, furthering the risk of acquiring opportunistic infections

Answer 450

Daunoxome (liposomal form of Daunorubicin) -\> tx KS - these are similar to chemo drugs with one exception: they are encased in microscopic fat bubbles which seem to lessen adverse SEs - studies have shown that these forms of drugs last longer and are able to move to the KS affected areas better.

Answer 451

- most common life-threatening fungal infection in AIDS -\> meningitis - signs and sxs: meningitis/ subtle sxs: fever,, HA, malaise

Answer 452

- latex agglutination serum/CSF testing for AG (CRAG) Tx: amphotericin B (Fungizone, Amphocin) prophylaxis: fluconazole (Diflucan)

Answer 453

- diarrheal disease caused by microscopic parasite Cryptosporidium - can live in the intestine of humans and animals and passed in the stool - Protected by an outer shell that protects it: allows it to survive outside of the body for extended periods, makes it very resistant to chlorine-based disinfectants - one of the most common causes of waterborne diseases in humans in the US - Parasite is found in every region of US and throughout the world. - \*\* Generally only affects immunocompromised pts

Answer 454

- most common: watery diarrhea -stomach cramps, dehydration, N/V, fever, wt loss - some pts asymptomatic - small intestine is most commonly infected - sxs begin 2-10 days following infection - non-immunocompromised sxs last 1-2 weeks - HIV pts w/ CD4 200: 2-4 weeks, however, may remain in carrier state and give to others or infect self if CD4 count drops

Answer 455

- millions of crypto parasites are released in each BM from infected pts: transmission through fecal oral route, swimming or bathing in contaminated water, drinking contaminated water (most filtration systems don't filter crypto spores)

Answer 456

- stool specimens for cryptosporidium - specifically ask for the test (not done on routine O&P on stools) - Acid fast staining, direct fluorescent Ab (DFA), or enzyme immunoassays

Answer 457

- no approved tx for HIV+ pts, if CD-4 count can be improved, they may have remission but no cure

Answer 458

- most common retinal infection in AIDS pts - signs: perivascular hemorrhages sxs: usually a painless loss of vision, often unilateral, blurred vision, floaters

Answer 459

- ganciclovir (cytovene) given in 2 phases: induction and maintenance, due to high relapse rates - alt: foscarnet (Foscavir): less likely to cause neutropenia, but has many other possible AEs

Answer 460

- candidal esophagitis: very common in HIV pts, suggestive sxs are tx and only non-responsive pts are give endoscopy - Hepatic disease: autopsy shows that liver is very frequent site for disease/neoplasms, many of these are subclinical, co-infection with Hep B and C is common, low level hepatic disease may be cause for persistent N/V - Biliary Disease: acalculous cholecystitis with sclerosing cholangitis

Answer 461

- is an AIDS defining illness, as opposed to oral candidiasis. occurring in individuals with CD4 counts less than 100

Answer 462

- a presumptive dx can usually be made with a recent onset of dysphagia, especially in the presence of thrush, and empiric anti fungal therapy may be started - if pt fails to improve clinically after 3-7 days of therapy, an endoscopy should be performed for a definitive dx - endoscopy reveals: classiv diffuse raised plaques that characteristically can be removed from mucosa by the endoscope. - brushing or bx of the plaques show hyphae that are characteristic of Candida species.

Answer 463

- fluconazole 200 mg as initial dose, then 100 mg by mouth once daily for 14 days, IV therapy can be given to pt if pt is unable to swallow pills. - alt (less effective) txs include itraconazole capsules 200 mg once daily or ketoconazole 200 mg once daily for 14 days

Answer 464

- its the time between infection and detectable HIV abs (before 25 days)

Answer 465

- time between infection and detectable HIV RNA (0-10 days)

Answer 466

- symptomatic disease: often precedes positive AB test (b/t day 15 and day 25), when HIV RNA peaks

Answer 467

Growth factor Cell-cell adhesion ECM-cell adhesion

Answer 468

It will begin to settle and spread across the surface It will gain some sort of polarity It will become motile NOTE: this is an active process, it is not just happening because of gravity. Energy is required to modulate cell adhesion and changes inthe cytoskeleton during spreading

Answer 469

a. Non-adhesive agar Very few cells enter S phase b. Small adhesive patch A small proportion of cells will proliferation c. Large adhesive patch Almost all the cells will start proliferating

Answer 470

a. A small patch of fibronectin The cell can stick but it can’t spread so it will probably die via apoptosis b. The same amount of fibronectin spread over a larger area The cell is able to stick AND spread so it will survive and grow NOTE: this shows that adhesion AND spreading is important for cell survival and proliferation

Answer 471

Anchorage dependence

Answer 472

There are heterodimer complexes of alpha and beta subunits They associate extracellularly via their head and each of the tail regions spans the plasma membrane

Answer 473

10 alpha and 8 beta There are over 20 known combinations

Answer 474

Short, specific peptide sequences (e.g. arg-gly-asp (RGD sequence))

Answer 475

Actin cytoskeleton

Answer 476

The alpha6beta4 integrin is found in hemidesmosomes in epithelia and it binds to cytokeratin instead

Answer 477

Most integrins – local adhesions al[ha6beta4 integrin - hemidesmosomes

Answer 478

It is a platform for signal transduction

Answer 479

Growth factors can generate signals inside the cell, which can act on the integrin complex and alter its affinity (this is important in bloodclotting)

Answer 480

A cell can receive information about its surrounding via adhesion to the ECM The ligand binds and opens the legs of the complex, allowing cytoplasmic signalling molecules to bind

Answer 481

When the mammary cells were placed on a culture medium with interstitial matrix (type 1 collagen), they formed clumps and were loosely associated When placed on a culture medium with basement membrane matrix (e.g. laminin), the cells formed a very ordered system (organoid) and even began producing milk proteins

Answer 482

Contact inhibition of cell division

Answer 483

Density-dependence – increased competition for growth factors

Answer 484

Anchorage dependence (ECM dependent) Density dependence (growth factor dependent)

Answer 485

They will move away from each other The motility on the side that made contact will become paralysed meaning that the cells can then move away from each other This prevents multi-layering This is CONTACT INHIBITION OF LOCOMOTION

Answer 486

Epithelial cells Endothelial cells Neurones Myocardium

Answer 487

Zonulae (belts) Maculae (spots)

Answer 488

Contact-induced spreading of epithelial cells Contact between epithelial cells leads to mutual induction of spreading, so that the total spread area of the contacted cells is greater than the sum of the two separated cells. This could result in a stable monolayer.

Answer 489

Many cell-cell junctions are calcium dependent In the absence of calcium/low calcium, the junctions will break down This leads to:  Increased MAPK activation  Decrease activity of p27KIP1 (Cdk inhibitor)  INCREASED PROLIFERATION When calcium returned to normal and the junctions were reformed:  Decreased MAPK activation  Increased activity of p27KIP1 (Cdk inhibitor)  DECREASED PROLIFERATION

Answer 490

The same results were achieved This showed that cell-adhesion affects proliferation

Answer 491

There is a cadherin domain that is transmembrane and projects extracellularly Cadherins are homophilic and associate with similar structures on adjacent cells Intracellularly, the cadherin is bound to beta-catenin, which is bound to alpha-catenin, which, in turn, is bound to the actin cytoskeleton

Answer 492

Normally, beta-catenin is rapidly degraded by APC so it doesn’t tend to achieve high concentrations in the cytoplasm Free beta-catenin in the cytoplasm (that is not broken down by APC) can bind to LEF-1 to form a complex that acts as a transcription factor This complex can then regulate gene expression and promote proliferation

Answer 493

The APC mutation means that the APC protein can no longer degrade beta-catenin as efficiently So beta-catenin accumulates in the cytoplasm, associated with LEF-1 and triggers increased proliferation

Answer 494

When bound to cadherin at the plasma membrane, beta-catenin is NOT available to bind to LEF-1 and cause nuclear effects Cytoplasmic levels of beta-catenin can rise if there is:  Inhibition of degradation  Loss of cadherin-mediated adhesion This can lead to the formation of beta-catenin/LEF-1 complexes that promote proliferation

Answer 495

When cadherins cluster together you can get changes in the activation of some of the small GTPases including Rac and Rho Changes in the small GTPases can induce proliferation

Answer 496

Proliferate uncontrollably (loss of density dependence) Become less adherent and multi-layer (loss of contact inhibition of locomotion and loss of anchorage dependence) Epithelia break down cell-cell contacts Not hayflick limited (express telomerase and become immortal)

Answer 497

Anything that will make the signalling pathway constitutively active e.g. Ras mutation, over-expression of growth factor receptors, signalling intermediates and signalling targets

Answer 498

v-Raf v-Jun

Answer 499

Cell-cell adhesion must be down-regulated (e.g. reduced cadherin levels) Cells must be motile Degradation of ECM must take place (matrix metalloproteinases (MMP) levels increased in order to migrate through the basal lamina and interstitial ECM) NOTE: the degree of carcinoma cell-cell adhesion is an indicator of how differentiated the primary tumour is and indicates its invasiveness and prognosis

Answer 500

gentamycin\* tobramycin\* amikacin\* streptomycin neomycin \* used the most

Answer 501

crosses outer bacterial membrane by passive diffusion via porin channels, then binds to 30s ribosomal subunit and thus inhibits protein synthesis Bactericidal: create fissures in outer cell membrane, resulting in leakage of intracellular contents and enhanced antibiotic uptake

Answer 502

\*transferase enzyme inactivates aminoglycoside -impaired entry of amino glycoside into the cell - receptor protein on 30s subunit may be altered or deleted Resistance depends on the amino glycoside: amikacin shows less resistance -\> only one locus that may be inactivated genta and tobra: 6 loci that may be inactivated

Answer 503

poorly distributed (no PO) and poorly protein bound but distribution is increased in pts with ascites, burns, pregnancy Don't undergo any significant metabolism Nearly all administered dose is excreted unchanged in urine \* dose adjustment is required in renal insufficiency Not required in hepatic disease

Answer 504

most common: serious infections caused by aerobic gram-negative bacilli including pseudomonas, enterobacter, serratia, acinetobacter, and Klebsiella - also used synergistically w/ other abx in tx of gram + infections -protozoa - mycobacterial: tobra, strepto, amikacin

Answer 505

against gram positive cocci - enterococcus faecalis endocarditis -\> ampicillin or penicillin +gentamycin or strept - staph aureus endocarditis -\> quicker killing (naficillin+gentamicin) -\> neglible anaerobic coverage

Answer 506

dose dependent -\> increasing concentrations kill an increasing proportion of bacteria at a more rapid rate -postantibiotic effect: antibacterial activity persists despite unmeasurable drug concentrations -may last for several hours

Answer 507

-serious, life threatening gm - infection -complicated skin, bone, or soft tissue infection - complicated UTI - sepsis - osteomyelitis - peritonitis and other sever intra-abdominal infections - severe pelvic inflammatory disease -endocarditis -mycobacterium infection -neonatal sepsis -ocular infections (topical) - otitis externa (topical)

Answer 508

septicemia, nosocomial RTI, endocarditis, complicated UTI, complicated intraabdominal infections, osteomyelitis caused by aerobic gram - bacilli - often d/c in favor of less toxic abx once organism identity and susceptibility has been confirmed. - enterococci in absence of high level resistance

Answer 509

-most widely used -both gm - and +(resistance can occur) -almost always used in combo (beta-lactam) - IV, IM -topical and ophthalmic

Answer 510

similar coverage as gentamicin, better pseudomonas coverage - more expensive than gentamicin - comes in soon for inhalation for cystic fibrosis -IV, IM, ophthalmic

Answer 511

used for resistant bacteria IV, IM

Answer 512

2nd line for TB in combo w/ other agents used w/ pen or ampicillin for enterococcus faceless endocarditis or viridian's strep endocarditis (some resistance) - IM

Answer 513

limited to topical and oral use (bowel prep for surgery -\> colorectal).

Answer 514

for intestinal amebiasis and hepatic coma/encephalopathy

Answer 515

Pregnancy: D (human risk, but benefits may outweigh risks) Lactation: unknown, probably safe - enter breast milk but not well absorbed orally

Answer 516

previous allergy or hypersensitivity reaction to aminoglycosides - myasthenia gravis: neuromuscular blockade risk too high

Answer 517

nephrotoxicity ototoxicity neurotoxicity neuromuscular blockade \*this is why serum levels are monitored

Answer 518

reversible, non-oliguric renal failure - elevated troughs RFs: old, renal dysfunction, dehydration, hypotension, liver disease, use of other nephrotoxins Monitor: renal casts, urine output, Cr, BUN - once daily dosing is less toxic - most nephrotoxic: neomycin, tobramycin, gentamicin

Answer 519

both vestibular and cochlear vestibular: 2/3-\> vertigo, ataxia, loss of balance, tinnitus cochlear: 1/3 -\> high freq hearing loss, deafness unusal - often irreversible, relationship to peak levels - neomycin, kanamycin, amikacin: most ototoxic

Answer 520

can produce curare-like neuromuscular blockade at very high doses given too fast in resp. paralysis. -possible w/ any route of admin -usually reversible w/ Ca gluconate

Answer 521

Chemotherapy agents- agalsidase Alfa/beta: gentamicin may diminish effect of drugs loop diuretics: may enhance adverse effect of ahminoglycosides -\> nephro and ototoxicity neuromuscular blocking agents: enhance respiratory depressant effect of NM blocking agents B-lactam: synergistic effect, cephalosporins can increase risk of nephrotoxicity Warfarin: enhance anticoag effect

Answer 522

use limited b/c of availability of less toxic agents with comparable efficacy and w/o need for serum [drug] monitoring. - still impt as 2nd line agent in tx of serious infections due to aerobic gram - and certain gram + - also impt in multi-drug regimen for certain mycobacterial infections

Answer 523

tularemia plague uncomplicated UTI caused by drug resistant negative organisms

Answer 524

b/c neuromuscular blockade risk is too high -\> paralyze diaphragm and die!

Answer 525

gram + -\> strep pneumo

Answer 526

inflammation of parenchymal structures of the lung in the lower respiratory tract (alveoli and bronchioles)

Answer 527

CAP: occurred outside of hospital or w/in 48 hours of hospital admission - in a person who has not resided in a nursing home or hospital in past 2 weeks Nosocomial pneumonia: hospital acquired, ventilator associated, health care associated (more drug resistant and virulent)

Answer 528

typical: caused by bacteria that multiply in alveoli, neutrophils and pus in alveoli, congregate in alveoli sacs, multiply and produce pus atypical: caused by infectious agents that multiply in spaces b/t alveoli (septum and interstitum) - viral infections, mycoplasm (lack a cell wall around their cell membrane)

Answer 529

- defect in usual respiratory defense mechanisms (cough, cilia, immune response) - large infectious inoculum or a virulent pathogen overwhelms the immune system

Answer 530

pneumonia infection occurred outside the hospital or w/in 48 hrs of hosp. admission - patients who are residents of long term care facilities are not included her because they are living in a healthcare facility

Answer 531

- 4-5 million cases a year in U.S. - 25% will require hospitalization - most common infectious cause of death world wide - among top 3 causes of death worldwide - incidence peaks in winter months - more common in older adults \> 65 - incidence has decreased since pneumococcal vaccine

Answer 532

- advanced age - alcoholism (aspiration) - tobacco use - COPD - asthma - immunosuppression - underweight - gastric acid suppressive therapy: allows pathogens to survive in gastric contents that normally would be killed by acid - regular contact with kids (daycare) - frequent visits to a health care provider

Answer 533

- strep pneumo (#1 causative agent) - H. influenzae - mycoplasma pneumoniae - chlamydia pneumoniae - staph aureus - Neisseria meningitidis - M catarrhalis - klebsiella pneumonia - gram - rods - legionella

Answer 534

influenza A & B rhinovirus respiratory syncytial virus (kids) adenovirus parainfluenza virus

Answer 535

- S. pneumoniae - M. pneumoniae - C. pneumoniae - respiratory viruses (less severe)

Answer 536

- S. pneumo - M. pneumo - C. pneumo - H. influenzae - legionella - respiratory viruses (worse symptoms)

Answer 537

- S. pneumo - Legionella (bad) - H. influenza - enterobacteriaceae\* - staph aureus\* - pseudomonas\* (\*= virulent)

Answer 538

- fungal: if insidious onset with a possibility of immunocompromise (on immunosuppressive meds, HIV?) consider fungal etiologies

Answer 539

Recent travel within 2 weeks, hotel stays or cruise ships - high fever \>104 F - male - multilobar involvement - GI sxs (watery diarrhea) \*\*\*\*unique to legionella - neuro involvement - diffuse parenchymal involvement on xray

Answer 540

- strep pneumo: most common, may have rust colored sputum - mycoplasma pneumonia:

Answer 541

- fever - cough - +/- sputum production - dyspnea - sweats - chills - H/A - rigors - pleuritic chest pains - pleurisy - hemoptysis - fatigue - myalgias - anorexia - abdominal pain

Answer 542

- appear acutely ill - fever - may have hypothermia (elderly) 36 C - tachypnea - tachycardia - decreased SpO2 - Rales/crackles (inspiratory) - bronchial breath sounds - dullness to percussion

Answer 543

- more likely to have subtle symptoms - weakness - decline in fxnl status - confusion or change in mental status - tachypnea is common

Answer 544

CXR: +/- urinary antigen testing: +/- (strep pneumo, legionella) CBC: +/- BMP: +/- ( maybe not necessary in younger pts)

Answer 545

CXR sputum gram stain urinary antigen testing: s. pneumo, legionella - rapid antigen test for influenza - prior to initiation of abx therapy: sputum culture (2 sets) -\> want to start abx within 6 hours - CBC with diff - CMP (legionella messes with electrolyte balance) - arterial blood gases for hypoxic patients - consider HIV testing in all adult patients

Answer 546

- always order a PA, and lateral Xray if possible - findings: patchy opacities, lobar consolidation with air bronchograms, diffuse alveolar or interstitial opacities, pleural effusions, cavitation

Answer 547

- helpful to assess severity - assess response to therapy - may take 6 weeks to completely clear (f/u until CXR is clear)

Answer 548

- consider a thoracentesis - dx eval of pleural fluid includes: glucose, LDH, total protein, leukocyte count, pH, gram stain and culture \*fluid will shift if turned on side - pleural effusion occurs in cancer, cancer increases risk for pneumonia because of decrease in immunity

Answer 549

- order fungal tests on sputum and test for mycobacterium if cavitary opacities are seen - likely need to obtain samples from bronchoscopy

Answer 550

when: - influenza infection preceded present illness - necrotizing pneumonia (destroying the lung tissue) - empyema: collection of pus secondary to infection - respiratory failure or shock - if MRSA infection: tx with vanco or linezolid \* CA MRSA is genetically different from HA MRSA

Answer 551

- determine if the pt warrants hospital admission or if it safe to tx as an output

Answer 552

C= confusion U= BUN\> 19 mg/dl R= RR\> 30 min B= BP= 90/60 age = \>65 \* 1 pt for each yes, hospitalize if \> 1, higher the points the higher the mortality \* get confusion from being hypoxic, hyper carbon -\> dehydration, elect. imbalance \* hypotension: worried about sepsis

Answer 553

- low sensitivity (39%) for ID of those needing intensive respiratory support - it is good at predicting 30 day mortality: 0-1: 0.7-2.1% 2 = 9.2% 3 or more = 15-40%

Answer 554

- 74% sensitivity for prediction of those needing intensive respiratory support

Answer 555

- azithro or clarithomycin or doxy (covers H. flu and is better for pts with hx of smoking

Answer 556

- Resp FQ or azithro or clarithro + high dose amox or high dose Amox-CL or cefdinir, cefpodoxime, cefprozil

Answer 557

- Respiratory FQ (levo) - or macrolide + Beta lactam: cefriaxone, ampicillin, cefotaxime

Answer 558

- respiratory FQ or Azithro - + antipseudomonal B-lactam: cefotaxime, ceftriaxone, ampicillin/sublactam - if at risk for pseudomonas add antipneumococcal + antipseudomonal b-lactams: piperacillin/tazobactam, cefepime, imipenem, miropenem + cipro or levo or antipseudomonal B-lactam + aminoglycoside + azithro or resp. FQ \* If MRSA is suspected: add vanco

Answer 559

- best outcomes if abx started within 6 hours of admission - customary to require first dose to be given in ED

Answer 560

- based on severity of presentation - recent abx use in the last 3 months - post influenza infection -\> think staph (MRSA) - suspicion of drug resistant organisms in the community - after obtaining culture and sensitivity results

Answer 561

- min. of 5 days (tx longer then a week, no benefit) - afebrile for 48-72 hours - average for meds other than azithro 5-7 days unless severe infection or other sites infected - azithro has a very long half life so duration of therapy doesn't equate to other drugs

Answer 562

- pneumococcal vaccine (against 23 strains of S. pneumonia), seasonal influenza vaccine

Answer 563

- decreased level of consciousness due to drug or ETOH use - seizures - general anesthesia - CNS disease - impaired swallowing - GERD - hiatal hernia - tracheal tubes - NG tubes - periodontal disease - poor dental hygiene

Answer 564

- inhalation of oropharyngeal secretions colonized by pathogenic bacteria: macro aspiration and chronic micro aspiration - Goes to dependent lung zones: posterior segments of upper lobes and superior and basilar segments of lower lobes

Answer 565

- necrotizing pneumonia - lung abscess - empyema

Answer 566

- Prevotella melaninogenica - Peptostreptococcus - Fusovacterium nucleatum - Bacteroides

Answer 567

onset: insidious fever, wt loss, malaise - cough productive of foul smelling sputum

Answer 568

- CXR and most likely CT scan of chest (won't see extent of damage with CXR -\> need CT) - can't do sputum culture due to contamination from oropharyngeal secretions - if sputum sample is needed: do a bronchoscopy or transthoracic/transtracheal aspiration - if aspiration suspected a swallowing eval is needed -\> RF: is having sleep apnea

Answer 569

- DOC: Clindamycin or augmentin or amoxicillin or PCN G + metronidazole - longer courses of therapy are generally needed, continue abx until CXR improves which may be a month or more - lf lung abscess -\> continue abx until resolution of abscess - may require surgical removal of abscess or empyema

Answer 570

if lung abscess, empyema, necrotizing pneumonia or sig. risk factors like recent LOC due to multiple factors \* not all cases of aspiration pneumonia are caused by anaerobes.

Answer 571

Methicillin is an antibiotic that is stable to a beta-lactamase producing organism so if something is resistant to methicillin it can be very dangerous because it means it is resistant to something that typically works against bugs that are resistant.

Answer 572

Because it lacks a peptidoglycan cell wall, not because it produces beta-lactamase. (penicillins and cephalosporins are inhibitors of cell wall synthesis - they will have no effect on this organism).

Answer 573

target the bacterial ribosome within the cell, not the cell wall.

Answer 574

It has a smaller (70S) than the mammalian ribosome which is 80S -\> it is composed of 50s and 30s subunits as opposed to 60s and 40s in humans -\> so protein synthesis inhibitors won't effect human ribosomes, it's selective.

Answer 575

tetracyclines macrolides chloramphenicol (ind. drug) clindamycin (ind. drug).

Answer 576

tetracycline: prototype, hardly used doxycycline: Super important!!! minocycline: acne demeclocycline

Answer 577

Binds to 30s subunit of bacterial ribosome, believed to block access of amino acyl-tRNA to mRNA-ribosome complex at the acceptor site, thus inhibiting bacterial protein synthesis.

Answer 578

Broad spectrum: active against many gram positive and gram negative organisms including anaerobes.

Answer 579

- any organism resistant to one tetracycline is resistant to all tetracyclines - cell develops efflux pumps (pumps drug out of cell) - forms ribosomal protection proteins

Answer 580

all tetracyclines adequately but incompletely absorbed thru oral ingestion

Answer 581

dairy foods (less of a problem with doxy)

Answer 582

concentrate in liver, kidney, spleen, and skin and bind to tissues undergoing calcification --\> teeth and bones -Doesn't penetrate CSF -All cross placental barrier and concentrate in fetal bones and dentition

Answer 583

concentration in liver -\> metabolized and conjugated--\> released in bile --\> reabsorbed in intestine and enter urine via glomerular filtration (doxy -\> bile and into feces)

Answer 584

Because instead of being filtered by the kidneys it stays in bile and is excreted into the feces.

Answer 585

Calcified tissues: deposition in the bone and primary dentition occurs during calcification of growing children -\> causes discoloration and hypoplasia of teeth and temporary stunting of bones for growth. Gastric discomfort: controlled if taken with foods other than dairy products. Phototoxicity: severe sunburn can occur when the patient taking a tetracycline is exposed to sun or UV rays Vestibular problems: dizziness, nausea, and vomiting occur with minocycline.

Answer 586

pregnant women (category D) Breast feeding women Children

Answer 587

Oral, IV, IM (not recommended b/c of pain and inflammation at injection site).

Answer 588

STDs, atypical pneumonia, exacerbations of chronic bronchitis, acne vulgaris, and great alternative for sinusitis and acute prostatitis

Answer 589

Because of decreased activity against staph aureus

Answer 590

DOC for mycoplasma pneumonia, chlamydiae (resp for variety of STI's), rickettsiae (Rocky Mountain Spotted Fever), and excellent for Lyme Disease

Answer 591

acne vulgaris (rarely anything else)

Answer 592

Tx of SIADH because of its inhibiting action of ADH. \*SIADH= syndrome of inappropriate antidiuretic hormone secretion

Answer 593

erythromycin: first one in drug class and prototype, not used nearly as much any more. azithromycin (Zithromax): most popular macrolide, used extensively in a variety of circumstances. Clarithromycin (Biaxin)

Answer 594

bind irreversibly to a site on the 50S subunit of bacterial ribosome, thus inhibiting the translocation steps of protein synthesis - Bacteriostatic

Answer 595

yes, because they are protein inhibitors not cell wall inhibitors

Answer 596

effective against same organisms as PCN G -\> used in pts allergic to penicillins. Also effective against chlamydial species and mycoplasma pneumoniae and legionella pneumophila

Answer 597

similar to erythro but also effective against H\> influenzae (community acquired pneumonia) \* Use instead of Azithro -\> new trend

Answer 598

less active against strep and staph than erythro but more active against respiratory infections due to H. influenzae and Moraxella catarrhalis. Excellent for urethritis caused by Chlamydia trachomatis

Answer 599

most strains of staph in hospital isolates are resistant to erythro clarithro and azithro show cross resistance to erythro \*Not good in skin coverage -\> don't use for staph aureus (MRSA)

Answer 600

alteration in the binding site of the ribosome. manifestation of an efflux pump to get the drug out of the cell. Enzymatic inactivation

Answer 601

Erythro: destroyed by gastric acid and therefore need enteric coated tablet, adequately absorbed on oral administration Clarithro and Azithro: stable to stomach acid and readily absorbed

Answer 602

widely distributed in tissue except for CSF

Answer 603

Erythro: cytochrome P450 drug Clarithro: metabolized by liver and may also interfere with other drugs Azithro: not a p450 drug and tends to have few interactions with other meds

Answer 604

Erythro and azithro primarily concentrated in the bile Clarithro and its metabolites are eliminated by kidney and liver -\> recommended that dosage be adjusted in pts with compromised renal function

Answer 605

GI distress including diarrhea big problem with erythro -\> leads to poor pt compliance (sometimes used for constipation even) Azithro and Clarithro are much better tolerated in GI Ototoxicity: transient deafness has been associated with erythromycin especially at high dosages. prolonged QT with erythro and clarithro (rare)

Answer 606

Fewer adverse effects fewer drug interactions don't have to worry about adjusting dose with kidney and liver disease unless severe Long half life -\> easy to use and pts are more compliant (daily dosing compared to 2x daily or 4x daily)

Answer 607

Nope, not good for staph just like doxycycline

Answer 608

because it works really well against chlamydial species - only have to dose single 1 gram versus a 7-10 day course of doxy

Answer 609

Excellent for broad spectrum coverage of both typical and atypical pneumonias, used all the time for exacerbations of chronic bronchitis in the patient with COPD - used first line alt. for group A strep pharyngitis (strep throat)

Answer 610

Active against wide range of gram + and gram - organisms but because of its HIGH toxicity, its use is restricted to life-threatening infections in which there are no alternatives!!

Answer 611

Binds to bacterial 50S ribosomal subunit and inhibits protein synthesis at the peptidyl transferase reaction

Answer 612

very broad -\> including anaerobes - not effective against pseudomonas or chlamydiae

Answer 613

completely absorbed orally Readily enters CSF

Answer 614

-Hemolytic anemia -aplastic anemia --\> idiosyncratic and usually fatal, occurs independent of dose and may occur after therapy has ceased! -Gray Baby syndrome -\> because of interference with human mitochondrial ribosomes, can lead to poor feeding, depressed breathing, cardiovascular collapse, cyanosis, and death - can interfere with a number of other drugs

Answer 615

same as macrolides --\> bind to 50s subunit of bacterial ribosome.

Answer 616

great coverage against anaerobic bacteria but also active against many gram + cocci: staph and strep

Answer 617

well absorbed orally, distributes well into all body fluids except CSF

Answer 618

Clostridium difficile -\> which is a bug that hangs out in gut and is usually harmless but with the administration of Clindamycin there can potentially be overgrowth of C. difficile which can lead to potentially fatal disease --\> pseudomembranous colitis with side effects of diarrhea, nausea, and skin rash

Answer 619

Clindamycin or Metronidazole (Flagyl) - Excellent in treating infections of the gut and used to treat penetrating wounds of abdomen and gut

Answer 620

gut flora or female genital tract flora

Answer 621

- sterility, cancer, and death

Answer 622

- unmarried - residence in urban area - new sex partners - multiple sex partners (concurrent) - history of a prior STI - illicit drug use - contact with sex workers - young age (15-24) - African-American race - admission to correctional facility or juvenile detention center -meeting partners on the internet

Answer 623

STI: - HSV - Treponema pallidum (syphilis) - Haemophilus ducreyi (chancroid) - chlamydia trachomatis (lymphogranuloma venereum; LGV) noninfectious etiology: Behcet's disease fixed drug reactions and trauma

Answer 624

- causative agents: HSV- 1 and HSV-2 - no longer separated into genital and oral - both serotypes can cause either type of infection Very common: 50 mill people in US - frequently under-recognized b/c infection is often subclinical

Answer 625

Primary: infection in a pt w/o abs to HSV-1 or HSV-2 nonprimary: 1st episode infection due to acquiring HSV-1 w/ preexisting abs to HSV-2 or vice versa Recurrent: reactivation of genital herpes in which the HSV type recovered in the lesion is the same type as the abs recovered in the serum

Answer 626

- Primary: highly variable from very symptomatic to asymptomatic - sxs tend to be more severe in women than in men - systemic sxs, local pain/itching, dysuria, lymphadenopathy - Dysuria can be due to acute urinary retention or more rarely to lumbosacral radiculomyelitis nonprimary: less symptomatic than first episode recurrent: less severe, shorter duration - asymptomatic shedding - if women get in cervix or vagina it could go unnoticed, shedding virus without lesions

Answer 627

- highly transmittable - can be transmitted by oral-genital contact - greater risk of acquiring HSV w/ male source - 70% of transmission occurred during periods of asymptomatic shedding - condom use 50% decline in transmission - HSV -2 genital ulcer disease has been linked to an increased risk for acquiring HIV-1 infection (any break in the skin increases risk of HIV)

Answer 628

- viral culture: if active lesions present - PCR: more sensitive - Direct fluorescent ab serology: - type-specific ab testing of serum - helps to determine if the pt is at risk of acquisition - determines if pt has hard evidence of prior infection - can do screening for HSV

Answer 629

drugs: acyclovir Famcilovir -\> more bioavailable Valacyclovir -\> more bioavailable/BID primary genital HSV: should be treated (w/in 72 hours) - decreases duration of symptoms - increases healing of lesions - decreases viral shedding - analgesics may be required/ sitz baths helpful Recurrent disease: chronic suppressive therapy: expensive and may not be covered by all insurance carriers - episodic therapy: start at 1st sign of prodromal symptoms usually take for 3 days - no intervention

Answer 630

- most common mode of transmission is from direct contact of fetus w/ infected vaginal secretions during delivery - Maternal immunity is impt: if mother contracted HSV before pregnancy -\> have abs that will transfer to baby - biggest risk: if mother contracted HSV while pregnant - Acyclovir can be used to tx a primary infection prophylactic C-section: do if active lesions at birth canal, not recommended if mother has no active lesions or if lesions have crusted at time of delivery (or have feeling of prodromal sxs), not recommended if have active nongenital HSV lesions

Answer 631

- counseling!!! - pts need to be educated that they may not have acquired the infection recenetly and that there has not necessarily been infidelity in a monogamous partner - education on recurrences - monogamous partner testing - telling future sexual partners

Answer 632

- Treponema palidum can't be cultured, can be seen with dark field microscopy - serologic tests available: nontreponemal: VDRL, RPR, TRUST/ reported as titers treponemal: reported as reactive or nonreactive: - fluorescent treponemal ab absorption - microhemagglutination test for abs to T. palidum - Treponema palidum particle agglutination assay - Treponema pallidum enzyme immunoassay

Answer 633

- pt with suspected disease - screening high risk populations (pts with other STIs, persons with multiple sex partners) - routine screening of pregnant women - commercial sex workers - all sexually active HIV infected pts at least annually, more frequent screening for those w/ multiple sex partners and unprotected intercourse

Answer 634

- reportable infection in the U.S. - number of cases increasing since 2001: primarily in MSM (HIV pop not using protection, syphilis started to spread then branched out into other populations - also in heterosexual pop. \*\*It is associated with an increased risk for acquisition and transmission of HIV - all pts who are dx with syphilis should be offered HIV testing and counseling

Answer 635

- Primary and secondary syphilis produce chancres, mucous patches and condyloma lata - estimated transmission occurs in 30% exposed to someone who is infected - syphilis can be spread by kissing or touching a person who has active lesions on the lips, oral cavities, breasts or genitals - it can be acquired through passage through the placenta

Answer 636

- incubation period of 2-3 weeks from inoculation - a papule forms and soon ulcerates to the chancre - chancre is usually painless - usually there is bilateral lymphadenopathy - chancres heal spontaneously within 3-6 weeks even without tx - widespread dissemination of the organism occurs at the same time

Answer 637

\* weeks to a few months later 25% of people with untreated infections will develop systemic illness: - rash: any form BUT vesicular, includes palms and soles. - Gray/white lesions warm moist areas -\> condyloma lata - systemic sxs - lymphadenopathy - alopecia (patchy) - hepatitis - GI abnormalities ( can be misdx as lymphoma) - musculoskeletal and renal abnormalities - ocular disease

Answer 638

- 1-25 years after secondary syphilis: early tertiary syphilis presents = year - late tertiary syphilis presents \> 1 year from initial infection systems involved: -subcutaneous tissue (gumma) - granulomas -CV: ascending thoracic aorta becomes dilated aortic valve regurgitation occurs. CNS (most common): early: meningitis, meningiovascular disease late: general paresis, tabes dorsalis, ocular, otosyphilis

Answer 639

- when suspected need to do a lumbar puncture CSF findings: lymphocytic pleocytosis, elevated protein, + CSF-VDRL and or FTA-ABS Need to follow CSF during tx to make sure there is a response (lumbar punctures)

Answer 640

For primary, secondary syphilis and early latent: - 2.4 mill units of benzathine PCN G IM - for PCN allergies DOC: doxy 100 mg BID for 14 days - tetracycline, azithro, and ceftriaxone are other alternatives although not well documented.

Answer 641

- pts with gumbos or CV involvement need to have a LP to r/o neurosyphilis tx - if they have localized disease tx is: - 2.4 mill units of benzathine pin G IM weeks for 3 weeks - gumma will resolve - it will only halt progression of CV disease and some prefer to treat CV disease like neurosyphilis

Answer 642

- IV PCN G either 3-4 mill units q 4 hrs or 18-24 mill units per day by continuous infusion for 10-14 days - pts who are allergic to PCN should undergo desensitization since PCN G is doc for tx neurosyphilis and an allergist should be consulted \* non-pcn regimens are not recommended for pts w/ documents neurosyphilis

Answer 643

- pts need to be reexamined clinically and serologically at 6 and 12 months after tx - a fourfold reduction in titer of the nontreponemal ab test is evidence of a response to therapy - a titer should be drawn just prior to starting tx and the same test and lab should be used for f/u - Think tx failure or reinfection if not getting better

Answer 644

- double stranded DNA viruses Papillomavirus genus - Human HPV only infects humans - more than 100 types of HPV - 75-80% sexually active adults will acquire genital tract HPV b/f age of 50

Answer 645

- genital warts (condyloma acuminatum) - Bowenoid papule and Bowen's disease - Giant condyloma (Buschke-Lowenstein tumors) - intraepithelial neoplasia and/or carcinoma of the vagina, vulva, cervix, anus or penis - plays a role in squamous cell carcinomas of the head and neck particularly in the oral cavity

Answer 646

- over 40 mucosal HPV genotypes infect lower female genital tract - carcinogenic types HPV16 & HPV18 account for 70% of all cervical cancers worldwide - HPV6 and HPV11 cause about 90% of genital warts

Answer 647

- most HPV infections usually resolve w/in 6-12 months (Including the carcinogenic HPV genotypes) - paradigm of cervical carcinogenesis: - HPV acquisition - HPV persistence - Progression of persisting infection to precancerous lesion - local invasion

Answer 648

- most common viral STI disease in the U.S. - 67% of pts -\> women - persistent infection especially w/ other risk factors (such as infection w/ HIV) can result in development of squamous cell carcinoma - acquisition is related to sexual activity - Fomites can also spread the virus

Answer 649

- depends on number, size, and location - asx - pruritus, burning - bleeding - tenderness, pain - discharge (women) - large condylomata can interfere with defecation intercourse and vaginal delivery - lesions in proximal anal canal may cause strictures

Answer 650

- usually made by visual inspection - document extent of involvement by PE, anoscopy, sigmoidosopy, colposcopy (looks at vagina and cervix), and/or vaginal speculum exam - 5% acetic acid causes lesions to turn white - biopsy can be considered: when dx is uncertain or presence of atypical features - lesions that don't respond to tx

Answer 651

- spontaneous regression occurs 20-30% of cases - al therapies have a 30-70% recurrence rate ablative: Podophyllin (CI in pregnancy) Imiguimod (Aldara) Trichloroacetic acid 5-fluoruracil (5-FU) - intralesional injected alpha interferon Excisional: cryotherapy (freezing) - laser therapy: reqrs anesthesia/ risk of scarring - excisional procedures w. knif or scissors: reqrs anesthesia, risks of infection and hemorrhage, need to send specimen to path

Answer 652

- gardisil 9: 16, 18, 31, 33, 45, 52, 58 (cancers: cervical, vulva, penile, vaginal, throat) 6 and 11 -\> anogenital warts recommendations for vaccine: - 9-26 in women -9-15 in males monitoring of women with pap smears currently recommended, needs to continue

Answer 653

-3 main causes: gonorrhea: common cause - usually can get discharge w/ milking the urethra, urethral swab: +WBC & +gram negative intracellular diplococci - chlamydia: common concurrent infection or may be primary - Trichomonas vaginalis: cause of nongonococcal urethritis (NGU)

Answer 654

- accounts for 20-35% of vaginitis dx in sx women in primary care settings - flagellated protozoan, humans only natural host - Trichomoniasis: - always sexually transmitted - assoc w/ high prevalence of coinfection w/ other STIs - organism can be ID in 30-40% of male sex partners of infected women

Answer 655

- asymptomatic carrier state - symptomatic cases: purulent, malodorous, thin discharge (70%) - burning, pruritus - dysuria, frequency -\> urethral involvement - dyspareunia, postcoital bleeding

Answer 656

- vaginal swab: wet mount for microscopy in normal saline - can see motile trichomonads (dx) - classic: green, frothy, foul-smelling discharge (4.5) & increased PMNs - culture on diamond's media: test not readily available, takes up to 7 days for results

Answer 657

- Metronidazole (Flagyl): single oral dose of 2 gems 500 mg BID for 7 days (if recurrent infection) - metranidazole tx for symptomatic pregnant women (if not sx -\> not tx) - male partners need to be tx for maximal cure rates in women - no intercourse until all parties are tx

Answer 658

- usually transient q/ spontaneous resolution and asx - sxs are typical for urethritis - no definitive dx tests: low yield with swabs for motile organisms - tx is usually b/c of + female dx or empirically for NGU

Answer 659

- 2nd most commonly reported communicable disease in U.S. - trend toward decreasing infections, lowest 1970s highest rates among: adolescents/ young adults minorities persons living in the SE U.S - increasing abx resistance

Answer 660

- women: any portion of the genital tract (PID -\> causes infertilitry, abscesses), most common site is the cervix, urethritis -men: urethritis, epididymitis, proctitis (anal region) - oropharyngeal infections: frequently asymptomatic

Answer 661

- occurs in 1-3% of pts infected - 3x more common in women than in men - hx of recent symptomatic genital infection is uncommon - asymptomatic mucosal infection predisposes - pt w/ decreased immunity more at risk: pregnancy, SLE, complement deficiencies

Answer 662

- triad: tenosynovitis, dermatitis, polyarthralgias: acutely systemic signs/sxs occur multiple tendons are inflamed (small joints) skin: painless lesions, few in #, transient purulent arthritis w/o skin lesions: - knees. wrist, and ankles most common joints - typically asymmetric, sometimes there is overlap with triad (joint will become septic if you don't tap and tx)

Answer 663

culture: can be difficult-\> organism fastidious gram stain: used primarily dx of urethritis in men Nucleic acid amplification testing (NAAT): recommended as optimal method for dx amplifies N. gonorrhoeae DNA or RNA sequences using various techniques - samples: endocervix, vagina, urine, urethra in men - not approved for nongenital sites (culture those)

Answer 664

- ceftriaxone preferred tx: resistance emerging -\> 250 mg IM single dose + (to cover tx of chlamydia) azithro 1 gram single dose or doxy 100 mg BID for 7 days except in pregnant women \* give in office - if allergic to ceftriaxone can give azithro 2 g single dose alt: cefotaxime and cefoxitin w/ probenecid

Answer 665

in men if intolerance to doxy then can use azithro \> but f/u evals are needed

Answer 666

- small gram - organism, oblique intracellular parasite - immunity to infection isn't long lived hence reinfection or persistent infection is common -4,000,000 cases in women are estimated to occur annually in U.S. -\> making it the most common STI - prevalence in men more difficult to determine -\> common to screen women and tx men empirically - chlamydia is on the rise in both genders

Answer 667

- asymptomatic, common presentation, usually picked up on routine check or culture - cervicitis - urethritis - PID: 30% of women w/ chlamydia will develop PID if left untx pregnancy: if left untx can increase risk of premature rupture of membranes and low birth weight - newborns can develop conjunctivitis and pneumonia (when mother untx)

Answer 668

- often coexists w/ gonorrhea so tx for both - 1st line agents: azithro: 1 g single dose - or doxy: 100 mg BID for 7 days (cheap) 2nd line agents: expensive and CIs: - ofloxacin for 7 days - levofloxacin for 7 days \* test for cure in pregnant pts

Answer 669

urethritis epididymitis: men

Answer 670

- culture - NAAT: vaginal, urethral, urine specimens (gold std) - AG detection: swab from cervix/ urethra - genetic probe: swab from cervix/ urethra - chlamydia rapid testing: under development \* reportable infection

Answer 671

- chlamydia - gonorrhea - syphilis - Hep B - offered test for HIV - take hx for HSV - pap done to assess for HPV

Answer 672

- ID those at high risk and screen - HIV positive persons need to be screened for other STIs - counsel safe sex behavior and protection especially those who are most likely to engage in risky behavior

Answer 673

- spore forming: rod, gram +: clostridium - nonspore-forming: gm +rod -\> propionibacterium, bifidobacterium, lactobacillus, eubacterium, actinomyces nonspore-forming gm - rod --\> bacteroides, fusobacterium, camplyobacter nonspore-forming gm + cocci -\> peptococcus, peptostreptococcus nonspore forming gm - cocci -\> veillonella

Answer 674

- clostridia are opportunistic pathogens, but they are responsible for some of the deadliest diseases including gas gangrene, tetanus and botulism. Less life threatening diseases include pseudomembranous colitis (c. difficile) and food poisoning. - cause disease primarily through the production of numerous exotoxins

Answer 675

perfringens, tetani, botulinum, difficile

Answer 676

1. entry through wound (rusty nail) 2. spread of toxin 3. disease: rigid paralysis ex: lockjaw, cardiac failure, respiratory failure 4. no exit

Answer 677

worldwide, ubiquitous in the soil, it is occasionally found in intestinal flora of humans and animals

Answer 678

tetanus or lockjaw. When spores are introduced into wounds by contaminated soil or foreign objects such as nails or glass splinters (no inhibition of ACh (in constant contraction --\> tetany)

Answer 679

Morphology: long and slender, flagella no capsule, terminal located round spore (drum stick appearance) Culture: obligate anaerobic, gram +, swarming occurs on blood agar, faint hemolysis Biochem activities: doesn't ferment any carbohydrate and proteins resistance: tolerate boiling for 60 min. Live for several years in the soil. classification and antigenic types: C. tetani is only species, no serotypes

Answer 680

-produces 2 exotoxins: tetanolysin, and tetanospasmin (type of neurotoxin, toxicity strong) - taken up at neuromuscular junction - Actions of tetanospasmin are complex and involve 3 components of the nervous system: central motor control, autonomic fxn, and neuromusc. junction. - retrograde transport to CNS -delitescence (latency): few days to several weeks - the 2 animal species most susceptible to toxemia are horses and humans

Answer 681

disseminates systemically -binds to ganglioside receptors, inhibitory neurons in CNS -glycine: neurotransmitter - spastic paralysis - severe muscle contractions and spasms - can be fatal

Answer 682

- initial sx: cramping and twitching of muscles around a wound, pt usually has no fever but sweats profusely and begins to experience pain, especially in area of the wound and around the neck and jaw muscles (trismus -\> lock jaw) - portions of the body may become extremely rigid, and opisthotonos (a spasm in which the head and heels are bent backward and body bowed forward) is common - complications: fractures, bowel impaction, intramuscular hematoma, muscle ruptures, and pulmonary, renal, and cardiac problems

Answer 683

involvement of bulbar and paraspinal muscles (truisms, rises sardonicus (creepy smile), difficulty swallowing, irritability, opisthotonos), involvement of autonomic nervous system (sweating, hyperthermia, cardiac arrhythmias, fluctuations in BP

Answer 684

- primary infection in head, particularly in the ear, isolated or combined involvement of CNs, particularly the 7th, very poor prognosis

Answer 685

involvement of muscles in area of primary injury, infection may precede generalized disease, favorable prognosis

Answer 686

generalized disease in neonates, infection typically originates from umbilical stump; very poor prognosis in infants whose mothers are nonimmune

Answer 687

- 1 mill. cases occur annually in the world -\> mortality rate ranging from 20-50%, rare in most developed countries - in developing countries, tetanus is still one of the ten leading causes of death, and neonatal tetanus accounts for 1/2 of these cases - in less developed countries -\> mortality: 85% neonatal tetanus and 50% non-neonatal tetanus - in U.S. -\> IV drug users victim to this - in untx tetanus, fatality rate is 90% for newborn and 40% for adults

Answer 688

humoral immunity (antitoxin), there is little, if any, innate immunity and the disease doesn't produce immunity in the patient - active immunity follows vaccination with tetanus toxoid

Answer 689

dx is primarily by clinical sxs, the wound may not be obvious - C. tetani can be recovered from the wound in only about 1/3 of the cases - it is imp. for the clinician to be aware that toxigenic strains of C. tetani can grow actively in the wound of an immunized person - numerous syndromes, including rabies, and meningitis, have sxs similar to those of tetanus and must be considered in d. dx

Answer 690

- infant: get DTap - (diphtheria, pertussis, tetanus) - tetanus toxoid: antigenic, no exotoxic activity

Answer 691

- offending organism must be removed by local debridement - toxoid - TAT (tetanus antitoxin; metronidazole (for more serious wounds - AIDS patients may not respond to prophylactic injections for tetanus toxoid

Answer 692

-found in soil, fecal contamination - causes gas gangrene: swelling of tissues, gas release from fermentation products (spores in anaerobic environment: release exotoxins) - wound contamination

Answer 693

- tissue degrading enzymes: lecithinase (toxin), proteolytic enzymes, saccharolytic enzymes --\> spongy, crackling noise made when palpated, gas is produced by enzymes and is a waste product from toxins - destruction of blood vessels - tissue necrosis - anaerobic enviro created - organism spreads

Answer 694

DEATH occurs within 2 days - effective abx therapy -debridement: get rid of necrotic tissue - anti-toxin - amputation & death is rare

Answer 695

- life threatening disease w/ poor prognosis and often fatal outcome - initial trauma to host tissue damages muscle and impairs blood supply -\> lack of oxygenation - initial sxs: fever & pain in infected tissue, more local tissue necrosis and systemic toxemia. Infected muscle is discolored (purple mottling) and edematous and produces a foul-smelling exudate; gas bubbles form from the products of anaerobic fermentation

Answer 696

- as capillary permeability increases, the accumulation of fluid increases, and venous return eventually is curtailed - as more tissue becomes involved, the clostridia multiply w/in the increasing area of dead tissue, releasing more toxins into the local tissue and the systemic circulation

Answer 697

- anaerobic -gram + - rod shaped - spore former - produces a protein neurotoxin - soil, sediments of lakes, ponds, decaying vegetation - intestinal tracts of birds, mammals, fish - found in honey, natural spores (don't give to infants less than 1 -\> don't have immunity) - found in improperly canned foods

Answer 698

- spores that are heat resistant, canning, anaerobic environment - botulism: eating uncooked foods, spores - GI, duodenum, blood stream, neuromuscular synapses - Binds to peripheral nerve receptors and block ACh neurotransmitter, - inhibits nerve impulses - leads to flacci paralysis - death b/c of respiratory and cardiac failure

Answer 699

- not an infection - resembles a chemical attack - 10 ng can kill a normal adult

Answer 700

- 18-36 hours - weakness, dizziness, dryness of the mouth - N/V - neuro features: blurred vision, inability to swallow, difficulty in speech, descending weakness of skeletal muscles, respiratory paralysis

Answer 701

- food poisoning: rare but fatal - comes from germination of spore - inadequately sterilized canned food -\> from home - not an infection

Answer 702

- uncommon, the predominant form of botulism - colonization occurs - no normal flora to compete - unlike adult botulism - don't give babies honey until 1 yo

Answer 703

- by clinical sxs alone - differentiation difficult - most direct and effective: serum or feces - most sensitive and widely used: mouse neutralization test 48 h - culturing of specimens 5-7 days

Answer 704

- individuals known to have ingested food w/ botulism should be tx immediately w/ antiserum - abx therapy if infection - vaccination will not protect hosts from botulism, however passive immunization w/ ab is the tx of choice for cases of botulism - need supp. care: respiratory support

Answer 705

- proper food handling and preparation - spores surviving boling (100 degrees at 1 atm) 1 hr - toxin heat-labile, boiling or intense heating, inactivate the toxin - bulge, gas -\> spoiled

Answer 706

after abx use - intestinal normal flora -\> greatly decreased - colonization occurs - enterotoxin secreted - pseudomembranous colitis

Answer 707

results predominantly as consequence of elimination of normal intestinal flora through abx therapy - sxs include abdominal pain w/ watery diarrhea and leukocytosis - pseudomembranous consisting of fibrin, mucus, and leukocytes can be observed by colonoscopy - untx pseudomembranous colitis can be fatal in about 27-44%

Answer 708

1st: discontinue initial abx (usually clindamycin) 2nd: specific abx therapy (doc: vanco , resistance to flagyl increasing)

Answer 709

throughout the body, in the muscle, cutaneous/sub-cutaneous necrosis - abscesses - deep: ex -\> liver infections - wound will be foul smelling - also see dental and sinus infections

Answer 710

- air in sampling -\> no growth b/c of O2 - ID takes several days at least -\> limiting usefulness - often derived from normal flora: sample contamination can confuse

Answer 711

1. most pathogenic anaerobes are usually commensals -\> originate from our own flora 2. predisposing conditions: breeches in mucocutaneous barrier so normal flora gets displaced, compromised vascular supply, trauma with tissue destruction - antecedent infection

Answer 712

complex flora: multiple species, less complex than normal flora, fecal flora: 400 diff species, species uniquely suited to cause infection predominate - synergistic mixture of aerobes and anaerobes: e. coli consumes O2 so anaerobes are allowed to grow and anaerobes promote the growth of other bacteria by being antiphagocytic and producing B-lactamases

Answer 713

1. infections in continuity to mucosal surfaces 2. infections with tissue necrosis, and abscess formation 3. putrid odor 4. gas in tissues 5. polymicrobial flora 6. failure to grow in the lab

Answer 714

Major disease causing strict anaerobic after abdominal surgery, non-spore-former -prominent capsule: anti-phagocytic, abscess formation -endotoxin: low toxicity, structure different than other lipopolysaccharide

Answer 715

- swelling and inflammation of the membranes covering the brain and spinal cord

Answer 716

- inflammation of the brain

Answer 717

- confined pocket of pus that collects in tissue, organs, or spaces inside the body

Answer 718

- newborn-1 month: Group B strep - 70% - age 1-23 months: S. pneumonia - 50% - age 2-18: N. meningitidis - 60% - adults to 50: S.pneumo - 60% - 50 and above S. pneumo

Answer 719

- disease of neurosurgical pts, trauma - organisms: E. coli, K. pneumonia, P. auruginosa strep, S. aureus, and coag neg staph listeria

Answer 720

- decline in Hib - increasing incidence of S. pneumo (50+% of cases in US) - shift from peds to adult disease - increase incidence of ATB resistance organisms esp S. pneumo PCN resistance: 35% Ceph resistance: 15-20%

Answer 721

- colonization of nasopharynx (N. menigitidis, S. pneumo, and Hib) - invasion of CNS following bacteremia due to localized source - direct entry of organisms in CNS from contiguous infection, trauma, neurosurgery, CSF leak or medical device (pacemaker) - host risk factors: asplenia chronic corticosteroid use immune comp - HIV or on immunosuppresants exposure to someone with meningitis

Answer 722

- virulence factors of pathogen overcome host defense mechanisms and invade CSF - CSF has inadequate humoral immunity so bacteria can multiply to high concentrations - bacteria can produce an inflammatory response through inflammatory cytokines - leads to vasogenic brain edema, increased ICP resulting in brain ischemia, cytotoxic injury (from bacterial secretions) and neuronal apoptosis

Answer 723

- duration of sxs 2-3 days sometimes but it can also progress over hours - triad: fever (95% have over 100.4 temp) nuchal rigidity: 88% change in mental status (lethargy) - other sxs: HA photophobia charcteristic rash (N. meningitidis) N/V neuro complications: seizures, focal beuro deficits, papilledema

Answer 724

- due to small hemorrhages under body - all parts of body are affected - rashes don't fade under pressure (non blanching) pathogenesis: septicemia wide spread endothelial damage activation of coag thrombosis and platelets aggreg reduction of platelets - sign of septicemia

Answer 725

- thorough physical exam including complete neuro exam - 2 tests that are specific: kernig sign: supine position, flex hip and inabilty to allow full extension when hip is flexed brudzinski sign: spontaneous flexion of hips during attempted passive flexion of neck - also check for passive flexion, extension and rotation of neck

Answer 726

- if pt has no fever, no neck stiffness, and no alt mental status - utility of PE in detecting meningitis not great, if you suspect meningitis strongly consider LP to definitely rule it out

Answer 727

- CBC with diff - CMP - UA - blood cultures x 2: 50-75% - LP: if delayed or deferred obtain blood cultures and start empiric ab therapy - possible CT to r/o mass lesion or other causes of IICP or route of infection

Answer 728

- immunocomp. or impaired cellular immunity - hx of seizure w/in 1 wk prior to presentation - any of following neuro abnormalities: \*hx of CNS disease (stroke, lesion, focal infection) \*alt Level of consciousness \*papilledema \*focal neuro deficit \* pts with these RFs should have CT done to ID possible mass lesions and other causes of IICP - over-employed dx modality leads to unnecessary delays in tx and added cost - rarely indicated in pt with suspected acute meningitis - mandatory in pt with possible focal infection - increased sensitivity with contrast enhancement (see cerebral edema)

Answer 729

- used to ID CIs to LP and complications that reqr prompt neurosurgical intervention such as sx hydrocephalus, subdural empyema, and cerebral abscess - indicated in pts who have evidence of head trauma, sinus or mastoid infection, skull fracture and congenital anomalies - may ID cerebral edema, effusion, hydrocephalus, abscess - may reveal cause of infection - may provide normal findings - dx of acute BM isn't made on basis of imaging - made by hx, PE and labs!

Answer 730

- not generally useful in acute dx - very helpful in investigating potential complications developing later in clinical course such as venous sinus thrombosis or subdural empyema

Answer 731

- elevated opening pressure - cloudy, purulent appearance - leukocytosis (1000-5000 with greater than 80% neutrophils) - protein of 100-500 mg/dL - glucose of less than 40 mg/dl

Answer 732

- gram + diplococci suggest S. pneumo - gram - diplococci suggest N. meningitidis - small pleomorphic gram - coccobacilli suggest H flu - gram + rods and coccobacilli suggest listeria

Answer 733

- mainly aimed at S. pneumo and N, meningitidis: cefotaxime (claforan) or ceftriaxone (rocephin) + vanco - for L monocytogenes (older than 50): ampicillin or PCN G + gentamicin alt: TMP-SMX or meropenem - nosocomiaL cover gram (-) (E.coli, K, pneumoniae and pseudomonas) and gram + use ceftazidime (Fortaz) + vanco \*tx time doubled in immunocompromised pts

Answer 734

- extremes of age - recent ATB rx - significant comorbid disease - HIV infection or other immunodeficiency - day care or day care pt/sib - recent hospitalization - congregate settings (correctional facilities, military, college dorms)

Answer 735

- IICP and cerebral edema - seizures - CN palsies (5-11%) - hemiparesis CV complications (rare): - vessel wall irregularities and focal dilatations - arterial occlusions - focal arterial bleeding - venous thrombosis - sensorineural hearing loss: greater with s. pneumo as cause

Answer 736

- early IV admin of glucocortiocoids has been eval as adjuvant therapy in an attempt to diminish the rate of hearing loss, cerebral edema, and other neuro complications as well as mortality - adding dexamethasone 0.15 mg/kg q 6 IV b/f or w/ start of abx reduces mortality and neuro disability in pts with GCS scores of 8-11 and pneumococcal dx - must be given early for best results - continued for 4 days if gram stain and/or culture consistent consistent with S. pneumoniae

Answer 737

- avoid sharing anything personal with anyone who could potentially be sick - good hand washing/sanitizing vaccines: -Hib (routine childhood) -PCV13 (routine) -PPSV23 (older children and adults) -Meningococcal conjugate vaccine (menactra): older children and adults -serogroup B meningococcal vaccine (Bexsero) CDC recommends all 11-12 yos be vaccinated with quadrivalent vaccine with booster at 16 - adolescents and young adults may also be vaccinated with serogroup B vaccine at age 16-18 if outbreak or complement component deficiences, fxnl or anatomic asplenia

Answer 738

-complement deficiency -fxnl or anatomic asplenia - microbio exposed to N.meningitidis - traveling to countries where disease is common - part of pop id'd to be at risk b/c of outbreak - first year college student living in residence hall -military recruit

Answer 739

- clinical and lab evidence for meningeal inflammation with neg bacterial cultures, most common cause is enterovirus, but other etiologies: mycobacteria, fungi, spirochetes, parameningeal infections, meds and malignancy

Answer 740

- fever - HA - stiff neck - photophobia - contrast to BM: aseptic meningitis is self limited course that resolves w/o specific therapy

Answer 741

- enterovirus, HSV, HIV, West Nile, varicella zoster, mumps, influenza, lymphocytic chorio-meningis virus (LCM), syphilis, lyme dz, fungal infections, TB, neoplasms of leptomeninges (breast, lung, melanoma, GI), NSAIDs, IVIG, TMP-SMZ

Answer 742

- comprehensive hx: travel, exposure, exanthems, drugs - if CSF with LP fairly clear, you can observe pt w/o abx - if uncertain, start on abx and wait 24-48 hrs for culture results: if pt improving and cultures neg then abx can be stopped if pt not improving and cultures neg may need to repeat LP and send for viral cultures and other specialized tests (PCR) depending on clinical situation - tx is supportive

Answer 743

- inflammation of brain parenchyma, manifested by neuro dysfxn - true incidence of encephalitis is difficult to determine b/c the clinical syndromes and results of routine lab tests are typically nonspecific - causes: viral post infectious autoimmune paraneoplastic med induced

Answer 744

- alt mental status (hall mark) - seizures common - focal neuro abnorm can occur - exaggerated DTRs and/or pathologic reflexes - motor or sensory deficits - altered behavior and personality changes - speech or movement disorders - hemiparesis, flaccid paralysis, and parasthesias

Answer 745

- CT can r/o space-occupying lesion or brain abscess - MRI detects demyelination and certain pattern clues to specific etiologies - EEG often abnormal

Answer 746

- status epilepticus - cerebral edema - inapprop secretion of ADH - cardiorespiratory failure - DIC - death

Answer 747

- presence or absence of normal brain fxn is impt distinguishing feature b/t encephalitis and meningitis - pts with men. may be uncomfortable, lethargic, or distracted by HA, but their cerebral fxn remains norm. - in encephalitis: abnorm in brain fxn are expected, included alt mental status, motor or sensory deficits, alt behavior, and personality changes and speech or movement disorders - seizures and postictal states can be seen in meningitis and shouldnt be just assoc with encephalitis - sxs and signs of meningeal irritation (photophobia and nuchal rigidity) usually absent with pure encephalitis - distinction b/t 2 entities is frequently blurred since some pts may have both parenchymal and meningeal process - meningoencephalitis

Answer 748

- only found in 35% of cases - HSV type 1 - arbovirus (arthropod vectored) - \*3 alpha viruses: Western, Easter, and Venezualan equine encephalitis \*flaviviruses: west nile virus, st. louis encephalitis, japanese B encephalitis, dengue and yellow fever - buny viruses: california encephalitis

Answer 749

- lyme disease - RMSF - rabies encephalitis - syphilis - TB - hx depending on travel, activity, area, time of year can give clues to etiologies

Answer 750

CSF: - may have increased WBCs with diff showing mostly lymphocytes - elevated protein, but less than 150 mg/dL - normal glucose

Answer 751

- knowledge of pts immune status is critical - dx: after all other tests a brain bx can be done as last resort, but in majority of cases of aseptic meningitis and encephalitis the cause isn't determined

Answer 752

- fever - malaise - stiff neck - sore throat - N/V - stupor leads to convulsions leads to coma - signs of UMNL (exaggerated DTRs, absent superficial reflexes, pathologic reflexes, spastic paralysis) - CSF protein and opening pressure increased and there will be lymphocytic leukocytosis - approx 1/150 infections will result in severe neuro disease - most sig RF is advanced age tx is supportive and RIBAVARIN - helpful

Answer 753

- rickettsia rickettsii: gram - intracellular bacteria endothelial cells: small vessel vasculitis - Southeast, summer - 2nd most common tick borne illness: Fever, HA, N, rash: 80% rash: blanching maculopapular, palms and soles, spreads centrally, later petechial and purpuric - hyponatremia, thrombocytopenia - CSF: increased lymphocytes/PMNs, increased protein, and neg gram stain - mild increase in LFTs

Answer 754

- clinical suspicion - low threshold to empirically tx - rash may be absent in 20% - RMSF serologies: initial may be negative, need convalescent titers several weeks later

Answer 755

- doxycycline 100 BID x 7 days - don't delay! - no indication for proph. tx after uncomplicated tick bite

Answer 756

- empiric tx if even suspected - in NC - any fever, HA, neuro syndrome will need tx - first serology titers not reliable - hyponatremia, low platelets, elevated LFTs, think RMSF - Don't wait for the rash

Answer 757

- Borrelia burgdorferi - deer tick (smaller) - NE/great lakes, but reported in almost all states - most common cause of tick borne disease - stages: 1. erythema migrans rash, viral like syndrome 2. multiple EM lesions and/or neuro and/or cardiac findings 3. late/chronic: intermittent or persistent arthritis and possibly subtle encephalopathy or polyneuropathy

Answer 758

- early: doxy 18-21 days amoxicillin 21-28 days cefuroxime 21 days -late or severe: cefotaxime (claforan) q 8 hrs PCN G q 4 hrs

Answer 759

- focal pyogenic infection, ringed by granulation tissue and outer fibrous capsule surrounded by edematous brain tissue

Answer 760

- chronic pulm infections, lung abscess or empyema - skin infections - pelvic infections - intraabdominal infections - esophageal dilation and endoscopic sclerosis of esophageal varices - bacterial endocarditis (brain abscess complicates 2-4% of cases) - cyanotic congenital heart disease (most common in children)

Answer 761

- (middle ear, sinus, teeth): otogenic (strep, bacteroides)- temporal lobe/cerebellum - sinogenic and odontogenic (anaerobic and microaerophilic streptococci) - frontol lobe - trauma: can develop years after the injury - post neurosurgical procedures: may also be delayed, more difficult to tx

Answer 762

- HA, fever, focal deficit (less than 1/3 of cases) - toxic appearance rare - seizures, vomiting, confusion, obtundation possible - frontal lobe - hemiparesis - temporal lobe-homonymous superior quadrant visual field deficit or aphasia - cerebellum - lim incoordination or nystagmus

Answer 763

- CT with contrast or MRI - LP CI!!! - needle guided bx or aspiration for confirmation or to direct tx in cases not responding - tx: -otogenic: cefotaxime -sino or odontogenic: Pen + flagyl - penetrating trauma or neurosurgery: Nafcillin + ceftazidime - hematogenous: Pen + flagyl - no obvious source: cefotaxime + flagyl

Answer 764

- LP - screening CT scan if worried about IICP but isn't necessary in majority of pts

Answer 765

- elevated WBCs, elevated protein and low glucose - absence of one or more ot typical findings is of little value

Answer 766

- advantage of suggesting the bacterial etiology one day or more b/f cultures are available

Answer 767

- CP - sore throat - fever - abdominal pain - N/V/D - rash - can be either primary or post infectious, but typically viral - get a good hx!!

33. Bacteriology 💢 Flashcards

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