Bacteria and Abx Flashcards

Question

Bacillus cereus

Answer 1

Gram + Bacilli Usually associated with food poisoning. Spores survive cooking rice. Keeping rice warm results in germination of spores and enterotoxin formation.

Answer 2

Gram + Bacilli Obligate Anerobe, spore forming Puncture wound with rust Causes a spastic paralysis (in contrast to botulinum) Toxin travels retrograde to spinal cord, cleaves SNARE, inhibits glyceine and GABA (inhibit the inhibitors, get spastic) in Renshaw cells Vaccine is toxoid vaccine so produce antibody response to toxin not to organism

Answer 3

Gram + Cocci Transmitted by improper canning of foods (preformed toxin). Spore forming, obligate anaerobe, only affect PNS (NOT CNS) Sx: flaccid paralysis that is descending (opposite from Guillon Barre). Cleaves SNARE protein, but target is motor neurons, ACh (when inhibitted, will cause flacid In babies, same flaccid paralysis. Likely ingested and lack flora. Usually from honey (spores in honey, not preformed)

Answer 4

Gram + bacilli, spore forming, obligate anerobe Nosocomial infection. can be caused by Clindamycin (esp by improper hand washing) Two exotoxins: A: binds to brush border of intestine (A for apple) cause wattery diarrhea B: Depolymerize actin, cause pseudomembrane colitis (B for licorice) PCR Assay to detect TOXIN, not bacteria in stool Tx: ORAL vancomycin (NOT IV), metronidazole

Answer 5

Gram + Bacilli, spore former that can be found in soil, obligate anaerobe 1. Motorcycle accident 2. Military accidents (both have large flesh exposed to soil) Can cause: 1. Gas Gangrene: gas produced under tissue as organism consumes carbohydrates. Produces α toxin lecithinase (produce a double zone of hemolysis on agar) Tx: IV PCN G 2. Food Poisoning: late onset (from ingesting spores), watery diarrhea. Transient, no tx

Answer 6

1. Clostridium Difficile 2. Clostridium Botulinism 3. Clostridium Perfringens 4. Clostridium Tetani Defined by: Gram-positive, spore-forming, obligate anaerobic bacilli.

Answer 7

Gram + bacilli, toxin inhibits Elongation factor 2 to inhibit protein synthesis (inhibiting the translocation step)--\> cell death --\> Pharyngitis with **pseudomembranes** (like C-Diff) in throat and severe lymphadenopathy (bull neck) Plated on Tellurite and Loeffler plates ELEK test to tell if toxic strain or not (usually immigrant who was not immunized) Toxoid vaccine routinely administered in US

Answer 8

Gram + Bacillus, catalase +, Beta hemolytic usually associated with infections in pregnent women (20x more likely) Motile (due to flagella) extracellular, when intracellular polymerizes actin (Actin rocket) Can survive cold temperatures (contaminate refrigerated items, milk, cheese) 3rd most common cause of meningitis in newborn (after group B strep and E. Colo) as well as adults \>60 years old Tx: ampicillin

Answer 9

Cause of pseudoappendicitis characterized by fever, vomiting, diarrhea, and right lower quadrant pain with imaging studies showing a normal appendix (also C. Jejuni is associated with pseudoappendicitis) - also associated with erythema nodosum (C. Jejuni is NOT) - associated with puppy feces, toddlers affected, transmitted via milk products, rodents are host in US, buboes form on skin, Streptomycin (with tetracycline) for treatment

Answer 10

**Bacteriostatic**: arrests the growth and replication of bacteria, thus allowing host immune system to complete pathogen elimination. Inhibition of protein synthesis (except aminoglycosides) **Bactericidal**: kills bacteria and reduces the total number of organisms. Inhibit cell wall synthesis, interference with DNA function or synthesis

Answer 11

Covers Gram + and Gram - bacteria ALL are Bacteriostatic! Ex: chloramphenicol, sulfonamides, tetracycline, trimethoprim - not really useful with immune compromised pts - Can cause superinfections, and growth of fungal infections

Answer 12

Pseudomonas aeruginosa, isolated in 38% of cases peaks between ages 7-12. Found in swimmers or someone who spends a lot of time in water (summer camp)

Answer 13

wild type terminus is D-alanyl-D-alanine, to which vancomycin binds. Vancomycin resistance is achieved by an enzyme that switches the terminus to D-alanyl-D-lactate, resulting in the loss of one hydrogen-bonding interaction, and a 1000-fold decrease in affinity. Alters cell wall peptidoglycan -Found in enterococcus often

Answer 14

sun sensitivity discoloration of teeth in children \<8 years old

Answer 15

_30S inhibitors_ **A** = Aminoglycosides [bactericidal] **T** = Tetracyclines [bacteriostatic] _50S inhibitors_ **C** = Chloramphenicol, **C**lindamycin [bacteriostatic] **E** = Erythromycin (macrolides) [bacteriostatic] **L** = Linezolid [variable] **“Buy AT 30, CCEL (sell) at 50.**

Answer 16

“part-of-a- virus” (parvovirus) is ssDNA. **B19 virus**—aplastic crises in sickle cell disease, “**slapped cheeks” rash in children** (erythema infectiosum, or fth disease) RBC destruction in fetus leads to hydrops fetalis and death, in adults leads to pure RBC aplasia and rheumatoid arthritis–like symptoms

Answer 17

Gram +: teichoic acid, thick peptidoglycan layer, stain purple on gram stain, single membrane, produce exotoxins primarily Gram -: endotoxin/LPS, double membrane, thin layer of peptidoglycan, outer membrane, stain red/pink

Answer 18

**T**hese **M**icrobes **M**ay **L**ack **R**eal **C**olor **T**reponema **M**ycobacteria **M**ycoplasma **L**egionella **R**ickettsia **C**hlamydia

Answer 19

stains glycogen, used to diagnose Whipple Disease "PaSs the sugar" Whipple Disease: foamy macrophages in intestinal lamina propria, mesenteric nodes. Cardiac symptoms, Arthralgias, and Neurologic symptoms are common. Most often occurs in older men.

Answer 20

1. PAS stain: Tropheryma Whipplei 2. Ziehl-Neelsen Stain: Acid fast bacteria (mycobacteria), Nocardia, protozoa 3. India Ink Stain: Cryptococcus neoformans 4. Silver Stain: Fungi, Legionella, H. Pylori

Answer 21

Lactose-fermenting enterics. Fermentation produces acid, causes colonies to turn pink ex: **K**lebsiella, **E**.Coli, **E**nterbacter and **S**erratia (weak) MacCon**KEE'S**

Answer 22

**Both** are gram + branching filamentous rods (Nocardia is weakly acid fast) **Nocardia** is aerobic, catalase and urease +, treat with sulfonuria **Actinomyces** is anaerobic, treat with PCN G

Answer 23

Partial reduction of hemoglobin causes greenish or brownish color without clearing around growth on blood agar - Strep pneumonia - Viridans Streptococci

Answer 24

Complete lysis of RBC. Clear area surrounding colony on blood agar - S. Aureus - Strep Pyrogens (GAS) - Strep Agalactiae (GBS) - Listeria

Answer 25

Easily spread in college dorms (has 15% mortality) - Has polysaccharide capsule, ferments maltose. - There is a vaccine but NO type B (most commonly infected with type B) - Resiratory/oral secretions Presentation: petechial hemorrhages, Waterhouse Friderichsen syndrome (adrenal insufficiency), fever, DIC, shock Tx: Ceftriaxone, Rifampin for prophylaxis in close contacts

Answer 26

Seen in Neisseria Meningocci -Hemorrhagic adrenalitis or fulminant meningococcemia is defined as adrenal gland failure due to bleeding into the adrenal glands

Answer 27

Gram - Dipplococci NO polysaccharide capsule NO maltose metabolism NO vaccine Can cause gonorrhea, septic arthritis (unilateral), PID (white purulent discharge), Fitz Hugh Curtic Syndrome (spreads to peritoneum), violin string adhesions to capsule of liver - cause neonatal blindness that happens immediately - hangs out in PMNs Tx: Ceftriaxone (add in azithromycin or doxycycline for possible concurrent Chlamydial infection

Answer 28

Small gram - coccobacillary (hybrid) rod. - Aerosol transmission - Culture on Chocolate agar (which contains factor V (NAD+) and X (hematin) Presentation: Ha**EMOP**hilis: Epiglottitis (cherry red, drooling child), Meningitis (capsular form, Type B), Otitis media, Pneumonia Tx: Amox/clav for mucosal, Ceftriaxone for meningitis Rifampin prophylaxis for close contacts

Answer 29

Gram - Rod...but gram stains poorly. Seem on Silver Stain. - Grows on charcoal yeast extract medium with iron and cysteine - Labs may show hyponatremia \<130 Concerning for Legionnaire's Disease and Pontiac Fever tx: macrolide or quinolone

Answer 30

**Legionnaires' Disease:** severe pneumonia (unilateral), fever (\>104), GI (diarrhea), CNS symptoms (HA, confusion). Common in smokers and in chronic lung disease Often arises from air conditioning sysyems, hot water tanks **Pontiac Fever**: flu-like syndrome that is self limiting

Answer 31

Gram - Rod, motile. Oxidase +, Obligate anaerobe. - Produces pyocyanin (blue-green pigment), has grape-like odor. - Produces endotoxin (fever, shock), and exotoxin A (inactivates EF-2) Associated with: Pneumonia (#1 cause), Ecthyma gangrenosum, UTI, Diabetes/IV drug use, Osteomyelitis, Otitis EXTERNA, Hot tub folliculitis Tx: Aminoglycosides, Fluoroquinolones, Extended spectrum PCN (piperacillin)

Answer 32

Rapidly progressive, necrotic cutaneous lesion caused by Pseudomonas bacteremia. Typically seen in immunocompromised patients

Answer 33

1. E**I**EC: microbe **I**nvades **I**ntestinal mucosa 2. E**T**EC: travelers diarrhea. Watery. from poor water (Montezuma Revenge) 3. E**P**EC: no toxin produced, diarrhea in **p**ediatrics 4. E**H**EC: **h**emorrhagic diarrhea, from undercooked **h**amburgers. associated O157:H7. Can cause **H**emolytic Uremic Syndrome (shiga-like toxin, damages 60S subunit). does NOT ferment sorbitol (defining feature from others)

Answer 34

Gram - Rod. Intestinal flora that causes lobar pneumonia in alcoholics and diabetics. Ferment lactose, Urease + **A**lcoholics **A**spiration pneumonia **A**bscess in lung and liver di**A**betics -Dark red "current jelly" sputum. Also causes nosocomial UTI's that are often MDR.

Answer 35

Gram - Rod, curved, terminally flagellated **TRIPLE +/TRIPLE therapy** **Catalase +, Oxidase +, Urease +** **A**moxicillin, **C**larithromycin, **P**PI (**A**bx **C**ure **P**ylori) -urease produces ammonia which creates alkaline environment which helps it survive acididc mucosa in stomach 95% duodenal ulcers caused H. Pylori, can progress to adenocarcinoma and MALT lymphoma

Answer 36

**Borellia Burgdoferi**-a spirochete, spiral shaped bacteria that does not gram stain well. Visualized wit aniline dyes (Wright or Giemsa stain) **Ixodes** deer tick is vector, mouse is reservoir, and white tailed dear is obligatory host. usually confined to Northeast USA Stage 1. erythema migrans (bulls eye rash), flu-like sx Stage 2: myocarditis, Bilateral Bells Palsy (CN VII) Stage 3: encephalopathy, arthritis (can migrate) Tx: Doxycycline if early, Ceftriaxone if later, more severe

Answer 37

**Spirochete** (spiral shaped bacteria with axial filaments) Found in water contaminated with **animal urine**. Prevelent in **tropics, esp Hawaii**. Causes **Leptospirosis**: flu-like symptoms, myalgias (calves classically), conjunctival suffusion (erythema without exudate), Cause **Weil Disease:** severe form with jaundice, and azotemia from liver and kidney dysfunction.

Answer 38

Caused by Spirochete Treponema Pallidum - Visualized by dark field microscopy or direct flourescent antibody (DFA) - Can do RPR or VLDR (although has false negatives with SLE, MONO, RF, Leprocy, IV drugs) - Primary - Secondary - Tertiary - Congenital Tx: ALL WITH PCN!!!!

Answer 39

Painless Chancre. Localized disease. VLDR + 80% in this stage. If not treated in 3-6 weeks, will progress to secondary

Answer 40

- Secondary=Systemic - Maculopapular Rash (including palms and soles) - Condylomata lata (smooth, moist, wart-like white lesions on genitals) - VDRL/RPR nonspecific. Use FTA-ABS test

Answer 41

Gummas (chronic granulomas) Aortitis (vasa vasorum destruction) Neurosyphilis (tabes dorsalis, general paresis) Argyll Robertson pupil (constricts with accomodation but is not reactive to light) = prostitute pupil

Answer 42

- Facial abnormalities such as rhagades (linear scars at angle of mouth) - Snuffles - Saddle nose - Notched Hutchinson teeth (notched incisors) - Mulberry molars - Short maxilla - Saber shins - CN VIII deafness

Answer 43

- Seen in syphilis patients several hours after abx are started. Flu-like syndrome (fever, chills, myalgia) - Due to killed bacteria (usually spirochetes) releasing toxins

Answer 44

- Caused by **Mycobacterium Leprae**, an **acid-fast bacillus** that likes **cool** temperatures. - Reservoir is **ARMADILLO** 2 forms: 1. **Lepromateous**: L=lethal. **Th2** response. Leonine (lion-like) facies. Highly communicable. 2. **Tuberculoid:** hairless skin plaques. **Th1** immune response. Tx: Tuberculoid: dapsone and rifampin (6 months) Lepromateous: **dapsone, rifampin, clofazimine** (2-5 years)

Answer 45

Usually positive in Syphilis, along with RPR -False positive in VDRL **V**: **V**iral infection (EBV, hepatitis) **D**: **D**rugs (IV drug use) **R**: **R**heumatic Fever **L**: **L**eprosy and **L**upus

Answer 46

Caused by Vancomycin due to a secondary realease of histamine -Can be avoided by slow injection (over 1-2 hours)

Answer 47

Alteration of Penicillin Binding Protein (PBP) and through expelling B-lactams with cell membrane efflux pumps

Answer 48

Pseudamonas and treatment is Gentamycin

Answer 49

**Bartonella Henselae** a gram - bacteria closely related to Rickettsia -appear as darkly staining bacilli on Warthin-Starry stain, a silver nitrate based stain

Answer 50

Painful genital ulcer with exudate, inguinal adenopathy Haemophilus ducreyi (it’s so painful, you “do cry”) 30% of people also present with painful inguinal lymph nodes Gram - coccobacillus

Answer 51

-Atypical pneumonias (Mycoplasma, Chlamydia, Legionella), STIs (Chlamydia), gram-positive cocci (streptococcal infections in patients allergic to penicillin), and B. pertussis.

Answer 52

- Gram - Dipplococci (synonymous with Neisseria) - Unable to grow on blood agar - Can be grown on headed blood agar called Chocolate Agar - VPN agar (polymycin, vancomycin, nistatin) - Thayer Martin agar = VPN agar - C5-C9 deficiency are more susceptible to Neisseria - Pillus is big virulence factor. Antigenic variation (why so good at evading) - IgA protease

Answer 53

**Endotoxin**: **LPS found in outer membrane of gram -** bacteria (both cocci and rods). Composed of **O antigen + core polysaccharide + Lipid A** (the toxic component\*\*). **Released upon lysis** or by living cells in bleds. Ex: **Meningococcemia**, sepsis by gram - rods **Exotoxin:** **Actively released** by certain species of gram + and gram - bacteria. Highly fatal at low doses. Toxoids used as vaccines. Ex: **Tetanus, botulism, diptheria**

Answer 54

**1. Cornybacterium diptheriae:** Inactive EF-2 **2. Pseudamonas aeruginosa:** Inactive EF-2 **3. Shigella:** Inactivate 60S ribosome by removing adenine **4. EHEC:** Inactivate 60S ribosome by removing adenine **5. ETEC:** Heat labile, increase cAMP. Heat stable, increase cGMP **6. Bacillus anthracis:** Mimic AC to increase cAMP **7. Vibrio Cholerae:** overactivate AC to increase cAMP **8. Bordetella Pertussis:** disable Gi, overactivate AC, increase cAMP **9. Clostridium Tetani/Botulinism:** cleave SNARE **10. Clostridium Perfringens**: alpha toxin phospholipase (lecithinase) that degrades tissue and cell membranes **11. Strep Pyogens:** Steptolysin O, degrades cell membrane **12. S. Aureus:** TSST, bind MHC II and TCR cause release of IL-1, IL-2, IFN-y, TNF-a --\> shock **13. Strep pyogens:** Exotoxin A, bind MHC II and TCR cause release of IL-1, IL-2, IFN-y, TNF-a --\> shock

Answer 55

Infectious agents that can cross placenta and cause congenital infections to fetus **ToRCHeS** * *T**oxoplasmosis * *R**ubella * *C**MV * *H**IV * *H**erpes virus * *S**yphilis

Answer 56

-Caliciviruses + ssRNA, Icosahedral, non-enveloped, fecal-oral transmission MAJOR cause of viral gastroenteritis. Often seen on cruise ships, can be caused by shellfish -Cause watery diarrhea, N/V

Answer 57

1. Mixed (also has the most Reed Sternberg cells) 2. Lymphocyte Poor

Answer 58

-Amoxicillin, Ampicillin, Aminopenicillin These are Animopenicillins that have wide spectrum. **"HHELPSS"** **H**. Pylori **H.** Infleunza **E.** Coli **L**isteria monocytogenes **P**roteus mirabilis **S**almonella **S**higella

Answer 59

**Cefazolin (ancef)**, a first generation cephalosporin given prior to non-abd surgery A subset of the second generation cephalosporins is the cephamycin group (cefoxitin). **Cephamycins** are used for their activity against **gram-negative gut anaerobes** (usually given before abdominal surgery), **B. fragilis** **E. coli** **Klebsiella** **Proteus**

Answer 60

- Meningitis, gonorrhea, disseminiated Lyme disease, Pseudomonas aeruginosa (ceftazidime only) - Important to note that 3rd generation cephalosporins can cross the CNS (reason why can treat meningitis)

Answer 61

-There are 5 different generations of cephalosporins with varying properties and coverage. As a general rule, progressive generations migrate from gram-positive to gram-negative coverage. Organisms typically not covered by cephalosporins can be remembered by the mnemonic **LAME** **L**isteria **A**typicals (Chlamydia, Mycoplasma) **M**RSA (ceftaroline is the exception) **E**nterococci

Answer 62

Group B Strep (Streptococcus agalactiae)

Answer 63

Cryptococcus Neoformans. India ink (clear halo). Tx with Amphotericin B

Answer 64

- Anaerobics (Bacteroides, Fusobacterium, Peptostreptococcus) or S. Aureus. - Most often found in R lung. Location depends on position during aspiration Upright: basal segment R lung Supine: posterior segment of right upper lobe or superior sebment of right lower lobe Tx: Clindamycin

Answer 65

-commonly found in **Purkinje cells of cerebellum** and in hippocampal neurons. Rabies has long incubation period (weeks to months) before symptom onset. Postexposure prophylaxis is wound cleaning plus immunization with killed vaccine and rabies immunoglobulin. Example of **passive-active immunity.** Travels to the **CNS by migrating in a retrograde fashion up nerve axons after binding to ACh receptors.**

Answer 66

Gram - Bacilli (zoonotic bacteria) - Lives in oropharynx of cats and dogs, often transmitted by bites. - Catalase +, Oxidase +, Grown 5% sheeps blood agar - Cause of osteomyelitis and cellulitis (\<24 hours) Demonstrates double staining (safety pin) Tx: PCN

Answer 67

Cause of Cat Scratch Fever Gram -, stained with Warthyn Starry Stain (SIlver) - Can cause lymphadenitis (axillary), can occur in healthy people - Also causes bacillary angiomatosis (raised red vascular lesions all over skin). Affects immunocompromised pts (HIV) (looks like kaposi sarcoma) Tx: Doxycycline for bacillary angiomatosis Bartonella usually self limiting, can use macrolides

Answer 68

-Gram - Bacilli Motility causes swarming on agar. Urease + Associated with struvite stones (ammonia, magnesium, phosophate), UTI Staghorn Calculus Tx: Sulfonamides

Answer 69

Gram - Zoonotic bacteria that causes Q fever. - Acquired through aerosols of cattle/sheep feces (via spores) - NO rash. - Obligate intracellular that resides within phagolysosomes (ONLY ONE TO LIVE IN THIS HOSTILE ENVIRONMENT)

Answer 70

DS linear DNA virus that is not enveloped -Most common cause of tonsilitis. Can cause pneumonia and conjunctivitis "pink eye" Can cause hemorrhagic cystitis Found in public swimming pools, children, military recruits Fecal/oral, respitatory droplet transmission Serotype 40,41 can cause gastroenteritis

Bacteria and Abx Flashcards

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