BIOL444 Lecture Notes - Type Three Secretion System, Oral Rehydration Therapy, Cholera Toxin
25 Dec 2012
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Document Summary
Set 07 infectious diseases of the intestinal tract. Developing countries: normally viral infection (e. g. rotavirus), death due to severe diarrheal ~50% for kids. Developed countries (e. g. canada & us): normally due to bacterial infections. Major syndromes: diarrhea (e. g. cholera): fluid-feces discharges, large amounts of fluid & electrolyte loss. Shigellosis: invasive colonization, shiga toxin, destroys mucosal cells of the large intestine. Transmission: fecal-oral, or via fingers, vectors, fomites etc. usually foodborne/waterborne. Control: sanitary & hygienic measures (disinfection of drinking water) Cholera: a disease of poor sanitation: vibrio cholerae: gram-negative curved rod, polar flagellum, alkali-tolerant, facultative anaerobe. Natural host are humans, but other vibrios (e. g. v. parahaemolyticus) can cause shellfish poisoning (marine organisms picked up by filter feeders such as clamps or oysters) viable but non-culturable state, stays alive for a really long time. Serogroup o1 is associated with epidemic cholera. The o-polysaccharide of the lipopolysaccharide (lps) is antigen specific.
