Veterinary Gram Negative Bacteriology, Veterinary Medicine. Exam Questions and answers, Graded A+

Veterinary Gram Negative Bacteriology, Veterinary Medicine. Exam Questions and answers, Graded A+ Family of 20 genera of gram–negative rods. • Enterics: natural habitat includes intestinal tract. – Grow in presence of bile salts, on MacConkey agar.--Enterobacteriaceae subset of enterics that ferment lactose. – E. coli – like organisms. Includes Klebsiella and Enterobacter species. – Indicators of fecal pollution: potential for presence of enteric pathogens such as Salmonella, viruses, etc.--Coliforms T/F: Escherichia coli are natural inhabitants of the large and lower small intestine of all mammals, and are in larger numbers in herbivors than omnivores and carnivores--F: E. coli are natural inhabitants of the GI tract but are more numberous in carnivores and omnivores than in herbivors Enteric infection: enteritis, diarrhea, scours. – Urinary tract infection (UTI). – Opportunistic infections: wounds, respiratory tract, mastitis, arthritis, etc. – Bacteremia, septicemia, septic shock (colisepticemia).--Escherichia coli How are Diarrheagenic types of E. coli. classified--Classification based on toxin production and pattern of intestinal colonization. – Most factors encoded by mobile genetic elements: plasmids, phages, transposons, pathogenicity islands. Enterobacteriaceae serotypes. • O = • H = • K = • F (P) =--• O = somatic, side–chains of LPS. • H = flagellar antigen. • K = capsular antigen. • F (P) = fimbria or pilus antigen. ETEC--Enterotoxigenic