W1 Flashcards

Question

What are examples of Bacteria without cell walls | - What colour do they stain?

Answer 1

They don't stain because they don't have a wall for the stain to attach too* Examples: Mycoplasma spp - Mycoplasma pneumoniae - Mycoplasma hominis Chlamydia spp - Chlamydia trachomatis Chlamydophila spp - Chlamydophila pneumonia - Chlamydophila psittaci

Answer 2

Capsule - fatty coat eg. Streptococcus pneumoniae Biofilms - where they live, hang out in possies, barf on each other, forming a sticky matrix that antiboitics don’t penetrate well i. e. catheters, deep central lines. The plastic ends form a biofilm that can cause an infection - Walking on river and slipping on the gooey rock = biofilms eg. Staphylococcus epidermidis Fimbriae - little hairs that make it stick on to a surface- nOT a pilus, a pilus is longer eg. Escherichia coli

Answer 3

another bacterial virulence factors ``` Lipopolysaccharide: Outer cell wall of Gram negative bacteria Endotoxin Leads to immune response - Cytokine release - Fever - Shock ```

Answer 4

Bacterial virulence factor They can work systemically or locally (G, CNS, resp)

Answer 5

Superantigens - Activate about 10% of lymphocyte pool - Directly bind MHCII presenting cells and T cells Toxic shock syndrome TSST-1 - S. aureus - S. pyogenes

Answer 6

Shigatoxin - Shigella dysenteriae - E. coli O157:H7 Shiga-like (vero)toxin - E. coli O157:H7 Toxins A and B - C. difficile Cholera toxin - V. cholerae ``` Food poisoning: - Staphylococcal enterotoxin S. aureus - CPE enterotoxin Clostridium perfringens ```

Answer 7

``` Botulinum toxin (Botox) -Paralysis “Sausage toxin” C. botulinum Tetanospasmin Tetanus C. tetani Shigatoxin seizures ```

Answer 8

Botulinum toxin (Botox) -Paralysis - “Sausage toxin” C. botulinum Tetanospasmin - Tetanus C. tetani Shigatoxin - seizures

Answer 9

Diphtheria toxin - Upper respiratory tract illness - Respiratory obstruction C. diphtheriae Pertussis toxin - Insulin-induced hypoglycemia - Whooping cough(?) B. pertussis Botulinum toxin - Through paralytic effect Necrotizing pneumonia - Panton Valentine Leukocidin - S. aureus

Answer 10

Tissue changes Alphatoxin - Gas gangrene - C. perfrigens Anthrax toxin - Edema factor - B. anthracis Exfoliatin - Staphylococcal scalded skin -syndrome - S. aureus Panton Valentine Leukocidin - Leukocyte and epithelial cell lysis Community-acquired MRSA Pyogenic exotoxin - Superantigen -Necrotizing fasciitis S. pyogenes

Answer 11

1. Shiga-like toxin 2. Verotoxin - Hemolytic Uremic Syndrome Hemolysis Bloody diarrhea Thrombocytopenia Renal failure - E. coli O157:H7 Enterohemorrhagic E. coli

Answer 12

gram positive bacterial toxin Causes lysis of phagosomes Allows the bacterium to replicate intracellularly Allows the bacterium to evade the immune system - L. monocytogenes

Answer 13

Resistance to antibiotics in the bacterial world all has to do with the concentration of the antibiotic that you can get into a specific tissue in order to overcome the *minimum inhibitory concentration* of that antibiotic for that particular bacterium

Answer 14

The lowest concentration of an antibiotic needed to prevent or inhibit the growth of a microorganism in the laboratory Must be able to correlate this clinically - Can we safely achieve such a concentration in a specific tissue?

Answer 15

a. Antibiotic Bioavailability | b. Antibiotic Toxicity

Answer 16

In their: Chromosomes AND on their plasmids These genes can be transferred from bacteria to baceries e.g. plasmids during bacterial conjugation

Answer 17

1. Are secreted and cleave antibiotics - Beta-lactamases, cephalosporinases - S. aureus, N. gonorrheae, Enterobacteriaceae (beta-lactamases, ESBL) 2. Form mutated binding sites for antibiotics Decrease antibiotic binding where they are supposed to act a. Mutated penicillin-binding proteins - S. pneumoniae and beta lactams - MRSA and all beta-lactams/cephalosporins/carbapenems b. Mutated cell wall - Vancomycin resistant enterococci c. Mutated gyrase enzyme - Ciprofloxacin resistance d. Mutated ribosomes - Aminoglycoside (eg. Gentamicin) resistance 3. Don't allow antibiotics (that act on ribsosomes or DNA) to enter the bacterium a. Mutates Porin proteins - Fluoroquinolone resistance b. Efflux pumps - Erythromycin resistance

Answer 18

They are either Yeast OR Mould Yeasts (examples include): Candida spp Moulds (examples include): Aspergillus spp Rhizopus spp Some fungi are dimorphic Yeast at 37oC AND mould at 25oC Histoplasma spp. Coccidioides spp

Answer 19

Contains CHITIN Polymer of N-acetylglucosamine Insects,crustaceans, mollusks, squid, and octopi also contain chitin Plants have cellulose instead- completely different Thus, Antibiotics would NOT work, because they target peptidoglycans specifically. you need anti-fungals

Answer 20

``` Not free living organisms Smallest of the micro-organisms Need a living host to replicate Use the host’s cellular machinery to replicate Host’s enzymes Host’s ribosomes etc ``` there are two major divisions DNA vs RNA viruses

Answer 21

``` Herpes virus group HSV 1 and 2 EBV, CMV. VZV HHV-6, 7, 8 Adenovirus Hepatitis B virus Human papilloma virus Parvovirus Poxvirus ```

Answer 22

``` Hepatitis A virus Hepatitis C virus Rhinovirus Measles virus Mumps virus Rubella virus Influenza virus Human Immunodeficiency Virus Enteroviruses Poliovirus Coronaviruses ``` Among many others

Answer 23

Many viruses cause chronic infections HIV, Hepatitis B, Hepatitis C, Human papilloma virus, HSV 1 and 2 Some viruses are never cleared from the human host Herpes group (HSV 1 and 2, EBV, VZV, HHV-6 etc) Adenovirus HIV Most of the viruses that remain in humans are DNA viruses Please note: HIV while an RNA virus initially, becomes a DNA virus once inside cells DNA viruses NEVER leave our bodies. They integrate into our own DNA i.e. chicken pox as a kid can become shingles later on Herpes comes back every time you’re stressed or immune system goes down. HPV: cervical cancer, anal warts/cancer RNA viruses are usually transient visitors EXCEPT HIV because it is a RETROVIRUS

Answer 24

RNA viruses are usually transient visitors EXCEPT HIV because it is a RETROVIRUS, that translates RNA into DNA and acts as a DNA virus that never leaves us. This is possible because it has an enzyme: reverse transcriptase

Answer 25

``` Some viruses cause cancer By integrating into our DNA By disrupting oncogenes - Hepatitis C - HIV - EBV - HPV - HHV-8 (Kaposi’s sarcoma virus) ``` Among others

Answer 26

Coronavirus group of viruses - Family of animal RNA viruses discovered in the 1930s (named in 1968) - Human coronaviruses discovered in the 1960s Name derives from the protein spikes it has on surface - Attachment to ACE receptors - Looks like a crown Latin: corona (“crown, “wreath”)

Answer 27

``` Like most respiratory viruses Large droplets (2 m or 6 feet away) ``` BUT: ``` Aerosols (potential for airborne spread) Aerosol generating procedures (AGP) CPAP Intubation/extubation Deep tracheal suctioning Open circuit suctioning (ventilated patients) Drilling Endoscopy with biopsy Flushing a high efficiency toilet Singing? Talking? Laughing? Shouting? Stool ```

Answer 28

Rapid Ag Tests (RATs) 50% sensitive when asymptomatic 70-80% sensitive when symptoms for more than 24 hours Repeat testing (12-48 hours later) needed if negative and you’ve tested “early” Close to 100% specific

Answer 29

10 days* to reduce your transmissibility | - throat is the first area that gets infected

Answer 30

NP (and throat) PCR is gold standard Almost 95% sensitive ( depends on a Cycle threshold) 100% specific - COVID infects throat area first so best to swab the throat, not nasal

Answer 31

significantly more infectious Multiple mutations in the spike protein Seems to have originated in parallel to other mutants Huge replication in throat and trachea Massive viral load in upper respiratory tract (main symptoms are sore throat and headache) Less predilection for lung tissue (not too much cough) Ro (R not) which was 2-3 for original wuhan virus has come up to 30!!! for omicron

Answer 32

It’s a mathematical equation: 1 – (1/R0) X 100% = “Herd immunity” calculation Then divide by vaccine efficacy (%) = TOTAL (not just eligible) population needed to be vaccinated in order to achieve said “herd immunity”. ``` Wuhan ancestral strain (R0 2.5) = 63% (remember that number?) Aα, Bβ variants (R0 4) = 79% Δδ variant (R0 8) = 97% Oo variant (R0 32) = 100% ``` This means young children (about 12% of Quebec population) need to be vaccinated, irrespective of whether the virus is “deadly” for them.

Answer 33

there is no cure or treatment however STEROIDS (anti-inflammatory) helps to suppress CYTOKINE STORM

Answer 34

Rare but serious syndrome <2% of children infected with COVID-19 (risk about 1 in 3,500) Mortality: <1% It occurs 4-6 weeks after (even from an asymptomatic) infection. Decreased by 90% after vaccinations

Answer 35

There are two types: | Protozoa vs Multi-Celled Organisms

Answer 36

anti-malaria drug | don't take it = become a skull

Answer 37

``` Single celled organisms Examples include: Plasmodium spp Entamoeba spp Dientamoeba spp Cyclospora spp Isospora spp Toxoplasma spp ```

Answer 38

``` Worms (examples include): - Nematodes/Roundworms Ascaris spp - Platyhelminths/Flatworms and Flukes Tinea spp Schistosoma spp Echinococcus spp ```

Answer 39

Increased risk of miscarriages, pre-term births, and maternal morbidity/mortality with COVID-19. Anti-COVID-19 vaccines have been approved and recommended for use in pregnancy (all trimesters) and for breastfeeding women. They are safe and effective and provide transfer of antibodies to the newborn. ``` Vaccines and menstruation changes? Study showed ½ day change only Other vaccines (and viral illnesses) can do this too. ``` Vaccines and infertility?

Answer 40

Start to acquire as soon as we are born After vaginal birth, neonate’s flora emulates maternal perineal flora; after C-section delivery, neonate’s flora emulates maternal cutaneous flora Quickly establish sites of colonization, especially after cessation of breast feeding There may be a role for the appendix as a source to colonize/repopulate the large bowel Flora maintains an equilibrium - Occupies binding sites, reduces available free nutrients - Contributes to host metabolism, provides host access to nutrients and vitamins In some circumstances, the flora can become opportunistic pathogens and contribute to disease.

Answer 41

Good = Commensal organisms Contribute to a stable ecosystem microflora which varies according to the site on or in the body Composition of the microbial flora is influenced by host microenvironments (nutrient availability, adhesion molecules, physical environment, atmosphere, etc) In a normal commensal state, interaction between the organisms and the host may or may not elicit a form of (protective) immune response

Answer 42

Bad: Opportunistic pathogens In situations of tissue breakdown, an otherwise benign member of the microflora may exploit the impaired defenses or upregulate virulence factors that result in disease pathogenesis

Answer 43

``` Evolved growth characteristics and/or virulence factors that facilitate: Adherence Invasion Immune evasion Tissue destruction Cellular dysfunction ``` Often result in an inflammatory response and upregulated immune response

Answer 44

``` CNS / PNS / ANS Lungs Heart Liver Spleen Pancreas Kidneys Uterus, ovaries, testicles ```

Answer 45

Blood Bone Muscle Tendons, ligaments

Answer 46

``` Pleural fluid Synovial fluid Peritoneal fluid Cerebrospinal fluid (Urine) ``` NB urine can become colonized, this does not necessarily represent an infection or disease state.

Answer 47

``` Skin (and its appendages) Sites of heavy colonization Conjunctiva Nose Mouth / Gums Pharynx Large bowel Vagina Anterior urethra (Bladder / urine) ```

Answer 48

Coagulase negative staphylococci - Staphylococcus epidermidis Corynebacterium spp. To a lesser extent - Viridans streptococcus - (much lesser extent) Beta hemolytic streptococci - (much lesser extent) Staphylococcus aureus

Answer 49

Gram positive cocci: Viridans streptococci Coagulase negative staphylococci Others, including Stomatococcus (Rothia) mucilaginosa

Answer 50

Aerobic: Pseudomonas aeruginosa Facultative anaerobic: E. coli, K pneumoniae, E cloacae Capnophilic: Capnocytophyga, Haemophilus, Neisseria Anaerobic: Fusobacterium, Prevotella, Leptotricha Others: HACEK, spirochetes

Answer 51

Neisseria spp Coagulase negative staphylococci Viridans streptococci Haemophilus spp.

Answer 52

99.9% Anaerobes – 1011 /g feces Bacteroides spp, Clostridium spp, Lactobacillus spp, Peptostreptococcus spp, Peptococcus spp. Spirochetes Aerobes / facultative anaerobes 108 /g feces – E coli 105-106 /g feces – Klebsiella spp, Proteus spp, Enterococcus spp, other Enterobacteriaciae Opportunistic Pathogens Normal flora resist colonization by pathogens, protect the balance

Answer 53

Lactobacillus spp Coagulase negative staphylococci ``` To a lesser extent: Streptococcus agalactiae (group B streptococci) Streptococcus spp. Mycoplasma Enteric gram negatives anaerobes ```

Answer 54

Advanced technologies and computational power has contributed to a new deeper understanding about the microbial flora We continue to learn about the intricacies of the microbial flora, and what can be cultured and identified (microbiota) and what makes up the entirety of the microbial genetic diversity whether it can be cultured or not (microbiome) Sites once considered “sterile” have been shown to have elaborate microbial ecosystems i.e urologic system, respiratory system Understanding the microbiome provides opportunities for basic research and even therapeutics

Answer 55

MALDI: cornerstone for microbiology, MALDI: uses mass spectrometry. specimen is crystalized then hit with a lazer in a vaccum tube that is chilled. Ions fly to sensor, depending on mass to charge ratio. Generates a spectrum and compared to the digital library to identify it.

Answer 56

D is most ACCURATE | however it is no readily available it most labs

Answer 57

Answer A, i.e its enough to allow us to treat and give antibiotics At least with broad spectrum antibacteria

Answer 58

Positive is Purple/blue = masculine Negative is Red/pink= feminine

Answer 59

Gram positive cocci | and Gram negative bacilli

Answer 60

1. Staphylococcus spp 2. Streptococcus spp 3. Enterococcus spp

Answer 61

1. Enterobacteriaceae/ Eneterobacteriales | 2. Haemophilus spp

Answer 62

``` Intracellular organisms minimal or NO cell wall Bizarre morphologies Difficult to culture Difficult to stain ``` i.e. chlamydia Rickettsia Mucoplasma Anaplasma

Answer 63

a. Catalase test: to see if it can utilize hydrogen peroxide at a high concentration to see if it will cause it to bubble catalyse positive = staphlococcus catalyase negative = streptoccus b. Coagulase Test: determines whether it can form a clot. This test helps define staphylococcus aureus c. Table top coagulase: also shows where the glutinase forms clumps d. Hemolysis: the degree to which an organism is able to completely lyse RBC Alpha = organisms that can partially lyse RBCs Beta = '' '' complete lyses Gamma = nil

Answer 64

s. aureus is a gram POSITIVE (purple, thick cell wall) it is a facultative anaerobe - colonization due to Fibronectin binding proteins - MSCRAMMs : marker molecule - NEVER consider this a contaminant infection: pyogenic (pus producing) - cellulitis, Furuncles, Abscesses, Osteomyelitis, endocarditis

Answer 65

Implies it is occupying an area, but not necessarily causing any important disease or inflammation low levels + intact skin = colonization high levels + break in skin = infection

Answer 66

TSST (Binds MCHII on APCs making them release proinflammatory cells= cytokine storm) leads to Toxic Shock Syndrome Exfoliatin Toxin causes SSSS(Staph scalded skin syndrome)/ Ritter's disease: painful, blistering red skin: self limiting Enterotoxin: on food, leads to food poisoning. In blood stream can =>TSS ^^ Hemolysins- attack RBC releasing Fe Leukocidin - attack leukocytes/WBC Two other things: - it also releases coagulase, which is able to form clots - Protein A: anchors antibodies inversely so it can't opsonize/compliment system neither.

Answer 67

a. staph are catalase positive: test that foams up confirms it is staph b. staph aureus is coagulase positive

Answer 68

These mutations progressively get worse and worse. People who frequently use antibiotics/develop greater resistance will have something lower on the list. ``` the SA at the end is for Staph Aureus first S = sensitive I = intermediate R = resistant M = Methacilin V = vancomycin ``` MSSA: penicillinase expression, Majority. 50% of cellulitis pts have MSSA, s for sensitivity. Penicilin gets degraded MRSA: expression of PBP-2a, mutation = resistance to B lactams used in AB VISA [Vancomycin sensitive]: Super bulky peptidoglycan wall, decoy targets VRSA: acquisition of vanA, genetically acquired, completely resistant to vancomycin

Answer 69

the degree to which we need AB to overcome resistance is increasing

Answer 70

s. epidermis - common skin flora - opportunistic pathogen- varied severity of disease - implant/foreign body biofilms [Forms biofilms on foreign bodies like catheters ] S. saprophyticus - fairly common agent of urinary tract infection S. Lugdunensis/ S. Schleiferi - potentially aggressive disease, including endocarditis

Answer 71

In hospital settings, patients are a group of people who are perscribed more antibiotics thus increased resistance levels: THUS increased virulence, multi-drug resistance will be seen Community acquired: PVL expression [?] tends towards cutaneous abscesses, some aggressive manifestations (pulmonary), stereotypical resistance pattern) so more options to treat with AB

Answer 72

These are the Beta-hemolytic strep They are catalase NEGATIVE (positive for staph*) organized as cocci in chains ex. steptococcus pyogenes leads to strep throat.

Answer 73

This is a GROUP A STREPTOCOCCUS Suppurative Diseases - pus forming Involve tissue, invasion damage and pus formation as opposed to i.e. Meningitis, Sinusitis, Pharyngitis, Tonsilitis, Pneumonia, Skin (Impetigo, Erysipelas, Cellulitis), Necrotizing Fasciitis, Myositis Non-suppurative Diseases - does not produce puss Non-suppurative complications occur after a latency period of a few weeks and include acute rheumatic fever, scarlet fever, streptococcal toxic shock syndrome, acute glomerulonephritis, and pediatric autoimmune neuropsychiatric disorder associated with group A streptococci

Answer 74

is an inflammation (swelling) of the protective membranes covering the brain and spinal cord. A bacterial or viral infection of the fluid surrounding the brain and spinal cord usually causes the swelling. However, injuries, cancer, certain drugs, and other types of infections also can cause meningitis.

Answer 75

is a common bacterial skin infection that causes redness, swelling, and pain in the infected area of the skin. If untreated, it can spread and cause serious health problems. Good wound care and hygiene are important for preventing cellulitis. Often Unilateral and lower extremities (athelete with swollen foot example in class)

Answer 76

is an infection of the upper layers of the skin (superficial). The most common cause is group A streptococcal bacteria, especially Streptococcus pyogenes. Erysipelas results in a fiery red rash with raised edges that can easily be distinguished from the skin around it.

Answer 77

aka flesh eating disease. s a rare bacterial infection that spreads quickly in the body and can cause death. Accurate diagnosis, rapid antibiotic treatment, and prompt surgery are important to stopping this infection. Cuts blood circulation which is what can lead to skin death

Answer 78

C! we are aggressive in treating step so we see less rhematic heart disease if not, can lead to RHD^ D. CAN'T be prevented with treatment. it will happen regardless.

Answer 79

ADHESION: - Lipoteichoic acid/Protein F - M protein > adhesive, anti-compliment, MOLECULAR MIMICRY* [bases for RHD] ANTIPHAGOCYTIC - Hyaluronic acid capsule ENZYMES: - DNase, Hyaluronidases, streptolysin SUPERANTIGENS - Toxic shock Syndrome

Answer 80

This is also a Beta Hemolytic Strep group most commonly: stepcocc agalactiae Neonatal Sepsis Neonatal Meningitis Prenatal Screening programs Diabetic Wound infections

Answer 81

This is an ALPHA hemolytic strep Diseases: - Pneumonia: common agent of community-acquired - Bacteremia - Meningitis - Sinusitis/ Acute Otitis media Asplenic host, antibody deficiences people are more susceptible

Answer 82

Virulence factors: - H2O2 production, pneumolysin, autolysin - most importantly: capsule, helps it avoid things Invasive strains/ Resistance strains - PRSP - 19 A Morphology - diplococci

Answer 83

``` Alpha hemolytic (some beta) Usually less virulent, can be members of the normal flora ```

Answer 84

Disease: Dental Caries, Bacteremia, Endocarditis, Abscesses S anginosus -> deep tissue abscesses - can mimic group A streptococcus but smaller colonies S mutans/ S Sanguis -> dental plaque and carries

Answer 85

Gram positive Non hemolytic [ but does group with the Lancefield group D] Normal Flora of the GI tract and biliary tract - Bile resistance, growth in high sodium content Two medically important species 1. E faecalis: LESS resistant 2. E faecium: Relatively quite resistant [IV therapies only mostly]

Answer 86

Disease: often a bystander- you don't need to treat it directly, treat everything else and it will go away UTIs, wound infections, intra-abdominal abscesses, cholangitis Bacteremia, endocarditis Therapeutics: Minimal number of oral agents with good activity Can employ syngergistic combinations Decreasing number of active agents VRE = Vancomycin Resistant Enterococcus - plasmid mediated resistance- vanA [gene] - Serious nosocomial [originating in hospitals] implications: wounds, lines, transfer or resistance genes

Answer 87

gram positive bacilli, spore forming Major food born illness ``` Disease INVASIVE: - Meningitis - chorioamnionitis -Granulomatous infantiseptics - Bacteremia, endocarditis ``` NON-INVASIVE - febrile diarrhea syndromes [culture negative]

Answer 88

Listerolysin, ActA - intracellular parasitism immune evasion by hijacking transport mechanism of host cell and pushing the organism into neighboring cells Difficult to diagnose in some cases - often confused for Corynbacteria in CSF** if you see coryn, think of LISTERIA as possibility*

Answer 89

Normal skin flora - rarely causing disease A few important pathogens: C diptheriae - toxin mediated- disruption of translational elongation - upper resp psuedomembrane - Multiorgan involvement - myocarditis, peripheral neuropathy, cutaneous lesions C urealyticum - renal disease/ calculi C Jeikeium - multiresistant, bacteremia

Answer 90

Gram positive and spore forming^ Disease B cereus - toxin mediated food poisoning (bad rice) - Immunocompromised infections ``` B anthracis Antharaz - zoonoses/ Cat A biological weapon - subterminal/ central spore - non motile - stereotypical appearance - White tenacious colonies, "snowy peaks", medusa heads ```

Answer 91

Larger family representing the gram negative rods that are commonly found in animal intestinal tracts General characteristics - gram NEGATIVE bacilli - oxidase NEG, catalase POS, - they FERMENT GLUCOSE*, reduce nitrate Vast majority are commensal organisms, some are opportunistic pathogens, some are virulent organisms unlikely to be found in abundance in a normal host - enteric pathogens, urinary pathogens, blood stream infection

Answer 92

``` Escherichia coli Klebsiella pneumoniae Salmonella enterica Enterobacter cloacae Shigella dysenteriae ```

Answer 93

All ferment glucose, but you can distinguish between them by a. Lactose fermenters b. Lactose non-fermenters

Answer 94

Klebsiella spp E coli Enterobacter Serratia spp (think Keys, KEES)

Answer 95

Salmonella spp Shigella spp Yersinia Enterocolitica

Answer 96

Helpful to identify "coliforms"/gram neg rods and lactose fermentation to distinguish between different enterobacteriaceae

Answer 97

B. because these are lactose NON FERMENTING so it will remain clear/yellow

Answer 98

The prototypical gram negative rod Primary culprit of urinary tract infections - Adhesion molecules, pili Can cause intra-abdominal infection, bacteremia and seed other sites Majority of E coli live in harmony with the colonic flora and immune system Some strains can make you very sick

Answer 99

ETEC = enterotoxigenic E coli Causes intraluminal accumulation of Na+ and water = dehydrated type of diarrhea Treatment is rehydrate

Answer 100

= enterotoxigenic E coli Diarrhea* Enterotoxigenic Escherichia coli (E. coli), or ETEC, is an important cause of bacterial diarrheal illness. Infection with ETEC is the leading cause of travelers’ diarrhea and a major cause of diarrheal disease in lower-income countries, especially among children. ETEC is transmitted by food or water contaminated with animal or human feces. Infection can be prevented by avoiding or safely preparing foods and beverages that could be contaminated with the bacteria, as well as washing hands with soap frequently. has the same pathogenesis of cholera Treatment: rehydrate

Answer 101

A zoonosis is an infectious disease that is transmitted between species from animals to humans

Answer 102

Zoonosis Not the only EHEC strain Shigatoxin like toxin production - Reactivation of lytic phage carrying toxin gene by physiologic stress (antibiotics) can enhance production and exposure - Damage to endothelium, glomerulus, CNS endothelium - TTP in adults, HUS in children (severe vascular outcomes) Majority are SORBITOL non- fermenting - use special SORB- MacConkey for diarrhea ( but may miss some!)

Answer 103

Disease Salmonella species - Gastroenteritis - Infection of vascular endothelium - Infection of organ systems i.e osteomyelitis - Typhoid fever Shigella species Has two mechanisms of disease: a. Direct invasion → apoptosis [bloody diarrhea] b. Shigatoxin → mucosal endothelial cell damage, Na disruption and intraluminal fluid accumulation

Answer 104

ingested into Small Intestine -> mesenteric lymph nodes -> Transient Bacteremia -> Multiplication in macrophages [liver, spleen, bone marrow] leads to a. Septicemia: Fever, kidney and other organs infected b. through bile into gall bladder -> cholecystitis, carrier state c. through bile into small intestine -> inflammation and ulceration of peyers patches -> diarrhea, hemorrhage, perforation This comes in WAVES, the different symptoms comes and goes and gets worse

Answer 105

Curved Gram negative rod Epidemic / Pandemic Toxin mediated disease Acquired from contaminated water, shellfish Profuse watery diarrhea Rehydration is most critical therapy Not distinctive on typical media for diarrhea

Answer 106

Gram negative bacilli - slightly thinner and longer than E coli Most commonly encountered **“glucose non-fermenter”** (NOT under enterobacteriaceae) Multiple species Soil and water pathogen P aeruginosa - Metallic sheen, smells of grapes - may express multiple important virulence factors - Characterized by green appearance → expression of pyocyanin and pyoverdin (these are both virulence factors) Can express a mucoid exopolysaccharide Can form BIOFILM- gel for organisms to exist in a metabolic state, difficult for AB to penetrate

Answer 107

Biofilms are a collective of one or more types of microorganisms that can grow on many different surfaces. Microorganisms that form biofilms include bacteria, fungi and protists. One common example of a biofilm dental plaque, a slimy buildup of bacteria that forms on the surfaces of teeth Biofilm Formation Process. Bacteria form biofilms in response to environmental stresses such as UV radiation, desiccation, limited nutrients, extreme pH, extreme temperature, high salt concentrations, high pressure, and antimicrobial agents.

Answer 108

Important nosocomial [hospital acquired] pathogen Severe manifestations in altered immunity - Febrile neutropenia, burns, cystic fibrosis patient Disease includes - Complicated urinary tract infections, ventilator associated pneumonia, line associated infections - Necrotizing otitis externa, “hot tub” folliculitis - Bacteremia, endocarditis, septic arthritis, osteomyelitis - Post surgical infection wide spectrum of disease seen^

Answer 109

Virulence factors - Pili, flagella, LPS, Exotoxin A, Proteases, Phospholipases - Alginate → antiphagocytic, biofilm formation Quorum Sensing - Autoinducers → “power in numbers” - like a pheromone system: send molecules into environement and other cells nearby will start to activate genes in concert to form biofilm, virulence, resistance factors etc. ``` MDR – Pseudomonas aeruginosa. Occurs due to: - Rapid acquisition of resistance genes - Alteration of outer membrane permeability - Limited therapeutic options ```

Answer 110

1. Pseudomonas 2. Stenotrophomonas maltophilia - ICU VAE/VAP ``` 3. Acinetobacter baumanii MDR Returned from Iraq ?via Germany ?via medical vessel ```

Answer 111

Gram negative diplococcus (paired-cocci) Obligate human pathogens Increased susceptibility in hosts with terminal complement cascade deficiencies, and humoral immune deficiencies Meningococcus (N meningitidis) - Agent of meningitis, meningococcemia → sepsis, shock, DIC - 5-10% asymptomatic nasopharyngeal carrier rate - Encapsulated - Multiplication in the blood stream vaccine preventable; YES vaccine for B extreme outcome: necrosis of tissue

Answer 112

This is a subtype of Neisseria/ (N gonorrhoeae) Agent of gonorrhea, PID, epididymitis, infertility Evade immune system by - phase variation – genetic mechanisms that facilitate oscillation between expression and repression of adhesion virulence factors - antigenic variation – genetic recombination resulting in altered pili expression Gonococcemia - Dermatitis-arthritis syndrome, bacteremia Increasing antibiotic resistance (British “super” GC)

Answer 113

Pelvic inflammatory disease is an infection of a woman's reproductive organs. It is a complication often caused by some STDs, like chlamydia and gonorrhea. Other infections that are not sexually transmitted can also cause PID

Answer 114

Gram negative small coccobacilli (coccoid-rods) Opportunistic pathogen Encapsulated – serotype a-f Disease - Classically Hib [heamo^ influenza b] associated with epiglotitis - Encapsulated → septicemia, meningitis - All → Pneumonia*, otitis media, conjunctivitis, sinusitis, osteomyelitis, skin infections Vaccination has protected most individuals from aggressive forms of disease

Answer 115

Septicemia, or sepsis, is the clinical name for blood poisoning by bacteria. It is the body's most extreme response to an infection.

Answer 116

put staph and this together on a plate: - Demonstrates “satellitism” - Growth around a streak of S aureus Identify different species given dependence  on growth supplements and hemolysis on a QUAD plate X – (unknown X-factor) hemin V – (vitamin) NAD

Answer 117

Neisseria meningitidis Haemophilus influenzae Streptococcus pneumoniae ``` There are others... However: there are vaccines available to protect against these specifically for people with: Hematologic disorders Splenectomy ```

Answer 118

``` HACEK agents of endocarditis: Aggrigatibacter (Haemophilus) aphrophilus Aggrigatibacter actinomycetemcomitans Cardiobacterium hominis Eikenella corodens Kingella kingae (Bartonella henselae → “?BAACEK” ) ```

Answer 119

Cat Pasteurella multocida - Rapidly progressive extreme cellulitis Dogs Capnocytophyga canimorsus Capnocytophyga cynodegnmi - these are problematic for people who are Asplenic, immunocompromised → shock, DIC Human bite Eikenella corrodens - Severe suppurative infection, septic arthritis, endocarditis

Answer 120

``` Disease Whooping cough - Catarrhal stage - Paroxysmal stage - Recovery stage ``` Chronic cough Virulence factors - Pertussis toxin (cAMP modulator), tracheal cytotoxin (murein analog), LPS, pili, filamentous hemagglutinin Extremely contagious, vaccine preventable

Answer 121

A few select examples of agents that mediate disease by toxin: B pertussis C diphtheriae V cholarae C difficile, C tetani, C botulinum

Answer 122

- these do not need oxygen at all. Normal microbial flora of colon In colon, outnumber E coli 1000 to 1 Some species found in oral pharynx, gums, deep structures of skin Often participate in polymicrobial infections Pulmonary abscess, peritonitis/abdominal abscess Pelvic infections Upper respiratory infections

Answer 123

Anerobes below the diaphram have B-lactamases but they don't above the diaphragm

Answer 124

Spore forming, Gram positive anaerobic bacilli Risk factors for serious infections: Antibiotic use Clindamycin, cephalosporins, fluoroquinolones Immunocompromised Elderly, cancer patient, low antibody levels ?Use of proton pump inhibitors Use of NG tube

Answer 125

Has 2 active toxins – TcdA and TcdB (A and B) Has a secondary binary toxin – cdtA and cdtB Treatments: Metronidazole, oral vancomycin**, fidaxomicin***, taper therapy, pulse therapy, IVIg, stool transplant (FMT)***

Answer 126

1. C. Difficile vegetative cells produce toxins A and B and hydrolytic enzymes. 2. Local production of toxins A and B leads to production of tumour necrosis factor-alpha and pro-inflammatory interleukins, increased vascular permeability, neutrophil and monocyte recruitment 3. Then the opening of epithelial cell junctions and epithelial cell apoptosis 4. Local production of hydrolytic enzymes leads to connective tissue degradation, leading to colitis, pseudomembrane formation and 5. WATERY DIARRHEA

Answer 127

The most prevalent bacterial component of the colonic flora Opportunistic pathogen once breach in colonic mucosa Minimal oxygen tolerance – upregulation of genes to defend against oxidative stress Antibiotic resistance and transmission of resistance elements by conjugative transposons - Clindamycin - >40% resistance  (go to for above the diaphragm) - Metronidazole - almost all susceptible (go to for below the diaphragm)

Answer 128

Oral spirochetes Fusobacterium necrophorum - Lemierre’s disease - Septicemia, jugular vein thrombosis, metastatic abscesses Aspiration resulting in anaerobic lung abscesses, empyema - Risk factors: Seizures, alcoholics, poor dentition

Answer 129

Chlamydophila pneumoniae, Chlamydophila psitacci, Coxiella burnetti, Mycoplasma pneumoniae, Legionella pneumophilia, Mycobacterium tuberculosis “walking pneumonia”: don't make people super sick Difficult to culture - It’s a problem when TB is the most likely organism to grow Molecular and serologic testing available - upper and lower respiratory tract discordance can occur with samples for molecular analysis Legionella urinary antigen can be performed - Only detects serovar 1

Answer 130

3. is false, one course is enough | everything else is true

Answer 131

Gram negative rod Associated with contaminated water systems in homes and institutions Acquisition via infectious aerosols and microaspiration Survives phagocytosis by immune phagocytes There are two forms: Replicative form ↔ transmissible form Immune response to virulence factors (flagellin) mainly responsible for signs and symptoms Pontiac fever- without the liver dysfunction and pneumonia

Answer 132

Draculunculus Medinensis

W1 Flashcards

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