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Medical Microbiology (Subject) / Diseases of Digestive tract (Lesson)
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- Transmission 4F Food Finger Feces Flies
- severe diarrhea Dysentery
- Intoxication Food containing toxin 1-48h
- Foodborne infection Entering and proliferation 12h-2 weeks
- toxin mediated infection bacteria infecting host production of toxin damages host
- S.aureus amino acids and B-vitamins needed (from animal origin) High osmolarity heat stable superantigen
- Bacillus cereus endospore formation heat stable toxin :vomiting & diarrhea
- Clostridium botulinum endospores anaerobic spoiled canned food toxin denatures at 80° after 10 minutes or 2-3min boiling flacid paralysis
- Clostridium perfringens endospores anaerobic chilli uncooled 8-10 min generation time watery diarrhea gas gangrene (tissue destruction, anaerobic conditions)
- Entero bacteriaceae: Salmonella S.enterica >2400 serovar can enter epithelial cells tyhpoid fever infect macrophages (systemic infection)
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- Entero bacteriaceae: Shigella Shigellosis S.dysenteriae, S.flexmeri, S.sommei shiga toxin kills host type III invasion system drill into neighbouring cells
- Entero bacteriaceae: Yersinia Yersinia enterocolitica infect intestinal tract contaminated food able to multiplay at 4°C Diarrhea ,fever + extreme abdominal pain
- Entero bacteriaceae: E.coli EHEC: Enteroheamorrhagic EPEC: Enteropathogenic ETEC: Enterotoxic EaggEC: Entero aggregative (O cell wall antigen, H flagella antigen)
- Entero bacteriaceae: EHEC & EPEC EHEC harmless to cattle may contaminate meat low infectious dosis <100 cells hemorrhagic colitis + hemolytic uremic syndrome shiga like toxin from phage infection
- Entero bacteriaceae: ETEC invasion of epithelial cells travelers diarrhea heat labile toxin (activates host adenyl cyclase) heat stable toxin (activates host guanyl cyclase) no inflammation no fever
- Entero bacteriaceae: Vibrio Cholerae G(-) f.aerobic, curved rods contaminated food(shellfish) or water (high dosis needed) penetrates mucous layer adheres to microvilli produces cholera toxin: diarrhea(water loss) ,muscle cramps(electrolyte loss) to survive drink 20L wata daily
- Helicobacter pylori peptic ulcer disease flagellated, moves into and within mucous layer of stomach posseses urease --> produces ammonia from urea (raises pH) also inflammatory HCL destroy weakened mucous --> ulcers formed
- Lysteria Monocytogenes G(+) non spore rods beta-hemolytic contaminated food (dairy) can grow at 4°C mild influenza ,meningitis pregnant women may lose child invading (act A) steals cytoskeleton
- Grow at 4°C Yersinia entericolitica Lysteria Monocytogenes