Term
| Staph Aureus pathogenesis |
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Definition
• α toxin, exfoliatin, TSST and enterotoxin
• Superantigen
• Acts on neural receptors in upper GI |
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Term
| Bacillus Cereus pathogenesis |
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Definition
• forms endospores
• EMETIC FORM: fried rice, pasta; heat stabile
• DIARRHEAL FORM: meat/sauce; heat labile |
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Term
| Gram + Bacteria that causes secretory diarrhea |
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Definition
| S. Aureus, B. Cereus, C. Perfringens, |
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Term
| Gram + Bacteria causes both secretory and inflammatory diarrhea |
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Definition
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Term
| Major cause of food poisoning in the US? |
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Definition
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Term
| C. Perfringens distinguishing features |
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Definition
• resistant to heat/cooking for >1 hour- BUFFETS
• double zone of hemolysis
• part of natural flora
• longer incubation 8-18 hours
• rarely have vomiting! |
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Term
| C. Perfringens pathogenesis |
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Definition
• >12 toxins
• α and θ cause lysis
• enterotoxin
• forms spores |
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Term
|
Definition
• Toxin A: enterotoxin
• Toxin B: cytotoxin |
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Term
| C. Diff distinguishing features |
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Definition
• Pseudomembrane Formation
• Dx with ELIZA
• Part of natural flora |
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Term
| B. Anthracis pathogenesis |
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Definition
• Forms endospores
• Poly D-Glu Acid Capsule
• Tri-Part Toxin; protective Ag, lethal and necrotic factor |
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Term
| Staph Aureus distinguishing features |
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Definition
• Mannitol Fermentation
• Golden Yellow Colonies
• **Ashley potato salad story |
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Term
| Bacillus Cereus distinguishing features |
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Definition
• Motile
• β hemolytic
• opportunistic pathogen
• infective with >105 org/g in food.
• Transmitted by spores on grains, veggies, pasta, dairy, meats |
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Term
|
Definition
| Forms spores but not endospores |
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Term
|
Definition
| Cause persistant, intermittent diarrhea in developing areas with poor sanitation and abundant vectors |
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Term
|
Definition
| Giardia Lambilia-replicate via binary fission |
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Term
|
Definition
| Entamoeba Histolytica-move via pseudopods and replicate via binary fission |
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Term
|
Definition
| Cryptosporidium Parvum, Cylclospora Cayentenenis, Microsporidia: non-motile. replicate via asexual/sexual schizony/sporogony |
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Term
|
Definition
| ingest cysts which form sting-ray shaped trophozoites in D. New cysts form in LI. Sucking disk of troph adheres to enterocytes causing secretory diarrhea |
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Term
|
Definition
-withstand filtration and chlorination
-need to be boiled for 1 minute at least
-cysts are infective upon release
-spread easily in daycare (fecal-oral) or while camping
-Sxs: abd pain, n/v/d x 1-3 wks with malabsorption (fatty, foul smelling d) |
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Term
|
Definition
| ingest cysts, which form trophozites in LI, then invade mucosa and produce more cysts. Troph in LI destroy RBC and produce protease (inflam diarrhea). Cysts are released in stool. |
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Term
|
Definition
-aqr'd via contaminated fruit, water, veggies or by fecal exposure during sexual contact.
-10% ppl are show sxs: flask shaped lesions and dysentary
-can have systemic infection (lung and liver abscess)
-85% are asymptomatic if bacteria is just in the lumen |
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Term
| Cryptosporum Parvum lifecycle |
|
Definition
ingest water contaminated by cysts, ingested oocysts release sporozoites in SI that invade enterocyte vacuoles (only destroy gap junctions)
-oocysts are immediately infective once outside the body |
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Term
| Cryptosporum Parvum features |
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Definition
-often transmitted in water parks
-most common cause of secretory diarrhea in kids
-may be life threatening in the immunocompromised.
-stain pink in acid fast stain |
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Term
| Cyclospora Cayetanensis lifecycle |
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Definition
| -ingest oocyts which have matured in the environ for at least 1 week.. Cysts continue dev in SI forming sporozoites |
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Term
| Cyclospora Cayetanensis features |
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Definition
-person to person spread is unlikely
-causes secretory diarrhea x 1-2 wks which may be prolonged, severe.
-dx with PCR assays
-often transmitted on basil, raspberries and other fresh produce |
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Term
|
Definition
-humans ingest or inhale spores which get into gut, lungs or eyes.
-usually infects ppl with low CD4 count
-intracellular spore formation
-causing sev diarrhea, disseminated dz and corneal infections |
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