Bacterial infection of GI3 Flashcards
Vibrio species like Vibrio cholera and parahaemolyticus
type, shape, oxygen, where live, pH and temps, what do they require for growth
- gram neg
- comma, curved shaped
- facultative anaerobes
- free living in water
- broad range of growth -temp/pH (susceptive to stomach acid)
- require sodium for growth
Vibrio cholera
- symptoms
- incubation
- duration
- how much diarrhea
- how does it spread
- inflammatory?
- asymptomatic to severe watery diarrhea
- 2-3 day incubation
- seven day duration
- 250 mL/kg rate of mucus, electrolyte and water-filled diarrhea
- spreads via contaminated water
- No
what’s important about immunity in regard to V. cholerae
- we can become immune to the particular O antigen type we were effected by but
- if bacteria use a different O antigen type then we are screwed!
what’s different in classic cholera biotype vs El Tor biotype
El tor is the current strain (7) that is more resilient and has a longer duration
pathogenesis of cholera toxin
- uses toxin co-regulated pilus to adherence to intestinal epithelial cells
- uses AB TOXIN to activate adenylate cyclase to increase cAMP and cause massive efflux of electrolytes and water with NO SIGNIFICANT CELL DAMAGE
how are Vibrio cholera diagnosed? Treatment?
- culture
- treat- rehydration-IV/Oral and without rehydration, mortality is 90%
Vibrio parahaemolyticus
symptoms
what causes V. parahaemolyticus
- symptoms- watery diarrhea TO BLOODY DIARRHEA, nausea, vomiting, abdominal cramps, low grade fever
- virulence is Kanagawa hemolysin- induces chloride secretion thus watery diarrhea
what is vibrio parahaemolyticus associated with eating
inflammatory?
treatment and prevention?
- shellfish and other seafood
- yes
- treatment- self limiting
- prevention- proper cooking of shellfish
Yersinia enterocolitica type of bacteria found in? symptoms? Inflammatory?
- gram neg coccobacilli
- found in contaminated water and food (improperly cooked pork)
- symptoms? FEVER, abdominal cramps and watery to bloody diarrhea
- last 1-2 wks
- yes
mechanism of Yersinia entercolitica
- not well understood but invades M cells in the terminal ileum like salmonella but invades via a different mechanism
- involves T3SS and injection of Yops (Yersinia outer proteins)
- products heat stable enterotoxin
diagnosis and treatment of Yersinia entercolitica
-diagnosis via culture of stool
treatment- self limiting
Clostridium difficile (C. diff)
type-
inflammatory?
symptoms
-gram pos anaerobe
-non invasive
-spore forming
-emerging nosocomial pathogen
-inflammation
symptoms-
1) asymptomatic,
2) CDAD (clostridium difficile associated diarrhea)
3) pseudomembrane colitis
4) fulminant colitis with toxic megacolon -which cause plaques on colon that may have to be removed
how does C diff work?
- Toxin AB causes damage to epithelial mucosa and causes host cell cytoskeleton to be damaged = BLOODY diarrhea
- this occurs when a pt is hospitalized and given many broad spectrum antibiotics that change the gut flora
- some hospital emplyees could have C diff on hands and touch them and they get c diff
- if immunosuppressed enough, get CDAD
diagnosis and treatment and prevention of C. diff
diagnosis- toxin in stool and culture is not helpful b/c it’s part of our normal biota
treatment- oral vanco and metronidazole
prevention- fecal transplant (EWW)
Enterohemorrhagic e. coli (EHEC) type reservoirs transmitted via inflammatory? body part?
- gram negative, facultative anaerobe
- animals like cattle
- transmitted via HAMBURGERS (eHec) and vegetables (washed with water from streams)
- yes
- large intestine
