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39 Cards in this Set
- Front
- Back
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What bacteria causes Traveler's Diarrhea (Montezuma's Revenge) and how does it cause it?
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Enterotoxigenic E. coli (ETEC)
produces LT and ST toxins causing release of chloride ions into the bowel (Gs protein is stimulated) and blockade of ions causing a gradient inside the bowel pulling water out of the tissues (stimulates guanalyate cyclase and an increase in cGMP), respectively |
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What E. coli causes a "stacked brick" appearance on culture?
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Enteroaggregative E. coli
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How does enterohemorrhagic E. coli (EHEC) cause bloody diarrhea?
How is it spread? |
Inhibits enterocyte protein synthesis resulting in cell death leading to bloody diarrhea, abdominal cramps d/t the Shiga-like toxin produced by EHEC
Fecal oral contact (sheep, goats, cows, deer - HAMBURGER) |
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What is the difference between EHEC and E.coli 0157:H7?
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EHEC produces hemorrhagic colitis (bloody diarrhea)
O157:H7 produces hemorrhagic colitis AND non-immune hemolytic anemia, thrombocytopenia, and acute renal failure d/t its preferential coagulation in the renal arteries (presents with hemorrhagic colitis and thrombotic thrombocytic purpura). |
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What are the types of E. coli that cause diarrhea?
What type of diarrhea do they cause? |
ETEC (enterotoxigenic) - watery
EIEC (enteroinvasive) - bloody EAEC (enteroaggregative) - watery EHEC (enterohemorrhagic) - bloody EPEC (enteropathogenic) - watery |
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What preformed toxins can be produced by Staph aureus to cause food poisoning w/in 30m?
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Enterotoxins A thru F (act as super antigens binding MHC II directly, causing massive T cell stim and cytokine release resulting in fever and hypotension).
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What symptoms does Toxic Shock Syndrome toxin cause?
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nausea, vomiting, watery diarrhea; may damage the liver, kidneys, CNS, mm, and blood cells
also causes a macular, erythematous rash that will undergo desquamation |
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What layer of the skin (top, middle, bottom) is cleaved by exfoliatin toxin?
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Middle layer is cleaved (palms and soles and hair and nails are affected - also causes electrolyte and water loss)
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What action does alpha toxin have on cells?
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Forms pores in cell membranes causing cell death and tissue necrosis
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What is group B strep?
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Streptococcus agalactiae
(Sepsis/meningitis in neonates) |
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What is group A beta hemolytic strep?
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Streptococcus pyogenes
(pharyngitis, tonsillitis, impetigo, scarlet fever, immunologic dz - glomerulonephritis or acute rheumatic fever, necrotizing fasciitis, cellulitis/skin infections) |
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What are the top 3 causes of sepsis in the neonate?
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GBS (Strep agalactiae)
E. coli Listeria monocytogenes |
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What are the top 3 causes of meningitis in the neonate?
may not be correct |
GBS
E. coli Listeria |
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What is an infectious marker for colon cancer?
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Streptococcus bovis (group D strep)
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What are the top 4 causes of biliary tree?
EEEK |
E. coli
Enterobacter Enterococcus Klebsiella |
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What two bacterias are most likely to cause endocarditis?
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Enterococcus and Strep viridans
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What three diseases can group A beta hemolytic strep cause?
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Pyogenic disease (purulent lesions)
Toxigenic disease (necrotizing fasciitis, scarlet fever, etc) Immunologic disease (rheumatic or post-strep glomerulonephritis) Strep pyogenes |
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What is the virulence factor that determines the type of group A beta-hemolytic strep and what does it do for the bacteria?
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M protein - interferes with phagocyte ingestion making it less vulnerable and it determines if the bacteria will be more rheumatogenic or nephritogenic
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What does streptokinase do in the body?
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activates plasminogen to dissolve clots
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What does streptodornase do in the body?
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DNAse
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What does hyaluronidase do in the body?
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spreading factor - digests a major component of connective tissue allowing the bacteria to spread between the layers of the skin - major factor in cellulitis
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What does erythrogenic toxin cause?
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Rash of scarlet fever - it's a super antigen that causes a fever with a rough, erythematous, diffuse rash with strawberry toungue and focal strep infection
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What is the importance of ASO titers?
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Measures antibodies to streptolysin O (anti-streptolysin O=ASO) which is used to confirm recent Strep pyogenes when post-strep glomerulonephritis or rheumatic fever is suspected
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Are Neisseria oxidase + or - and what culture dish do they need to be grown?
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Oxidase positive
Chocolate agar |
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What enzyme does Niesseria meningitidis use to colonize the throat?
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IgA protease - destroys IgA antibodies on mucosal surface allowing it to spread into the blood and on to the meninges
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What symptoms does Waterhouse-Friderichsen Syndrome cause in pts?
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In addition to meningitis, pt develops fever, cyanosis, petechiae, and bilateral adrenal hemorrhage
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Why can a pt develop antibodies to N. meningitidis but not N. gonorrheae?
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Gonorrhea doesn't have a capsule so it is more easily phagocytosed which results in no ab production
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Why does N. gonorrheae not typically develop into a systemic infection? What is the most common outcome of systemic spread?
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It's not encapsulated so the immune system keeps it under control in a focused area
Typically systemic spread will cause gonococcal arthritis or tenosynovitis (PURULENT synovial fluid!) |
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What are the gram - rods of the respiratory pathogens?
"Gram neg rods cause Her to Lose Breath." |
Hemophilus
Legionella Bordetella |
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What are the gram - zoonotic rods?
Yaks Browse in Fenced Pastures |
Brucella
Francisella Pasteurella Yersinia |
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All enterobacteriaceae are able to ferment what substance? What is the exception?
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All are able to ferment glucose for alternate energy when O2 isn't available
Pseudomonas, obligate aerobe |
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What are the medically important gram + rods?
Which two are spore forming? B, Cl Which two are non-spore forming? Co, L |
Bacillus
Clostridium Corynebacterium Listeria |
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What are the 3 components of Anthrax Toxin?
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Edema factor (can crush organs/blood supply)
Protective antigen (forms pores in cell membranes to allow edema and lethal factors to enter - ANTIGENIC!) Lethal factor (blocks messenger system for cell growth) |
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What is the cutaneous symptom of anthrax?
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Black, crusty, painless ulcer
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What is the alternate name for Pulmonary Anthrax?
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Woolsorter's disease
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What is the pharmacologic treatment protocol for anthrax?
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PCN is the DOC but until it is proven sensitive tx it with:
Cipro or Levofloxacin or Doxycycline PLUS Clindamycin and/or Rifampin +/- Raxibacumab Continue his protocol until confirmed PCN sensitive OR for 60d (bioterrorist form) or 7-10d for endemic |
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How does Corynebacterium diphtheriae produce its toxin?
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It only produces the exotoxin when it is infected with a bacteriophage (which is what actually produces the toxin)
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What is the tx for diphtheria?
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Antitoxin + Erythromycin (PCN G is alt)
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How does Listeria move from cell to cell? What foods are the MC source?
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Actin rockets
Unpasteurized dairy (esp cheese like brie), processed meats, undercooked chicken |
