80 likes | 105 Views
Explore the characteristics, disease associations, and transmission methods of Gram-negative enterics like Escherichia, Salmonella, and Yersinia, along with other facultative anaerobic bacteria. Learn about their impact on health and the environment.
E N D
Gram Negatives 3: Enterics and other Facultative Anaerobes Includes: Escherichia Proteus Vibrio Enterobacter Serratia Pasteurella Klebsiella Hemophilus Salmonella Bordetella Yersinia
Family Enterobacteriaceae – “the enterics” • Assoc with GI tracts of animals • Identified by slight biochemical differences • IMViC, TSI, MAC, EMB • All small, fac. an. bacilli • Major nosocomial agent of septicemia, UTI’s, and intestinal infections • “non-path enterics” = EC,KP,EA,PV,SM • “path enterics” = Salmonella, Yersinia, Shigella
Escherichia • “workhorse” of biotech lab • 107-108 per gr fecal matter • Intestinal disease agent: • Gastroenteritis • 5 groups of path strains • Endotoxin and exotoxins • Extra-intestinal disease agent: • Community acquired UTI • Nosocomial (25%) • Neonatal meningitis & septicemia
Salmonella • Inhabit GI tract poultry/cattle • Transmitted via fecal-oral route • Extremely hardy! • Serovars and biovars • Disease states: • Gastroenteritis • Enteric (typhoid) fever • Bacteremia (chronic carrier) • Assoc with eggs/foods made with eggs
Yersinia • c.a. of bubonic/black plague • 3 large epidemics • Rat reservoir/flea vector or via infected tissue of rabbits/rodents • Bac migrate/accumulate in lymph nodes -> buboes! • Can be transmitted via aerosol
Vibrio • Slightly curved; fresh/marine • c.a. of cholera (V. cholerae) • Secrete choleragen exotoxin • Loss of up to 1 L per hour • Mortality >50% untreated (<1% with treatment) • V. parahemolyticus in VA From raw/undercooked seafood
Haemophilus • Encapsulated strains are pathogenic • H. influenza produces 2º infection of sinus membrane • Leads to: • Bac meningitis • Pneumonia • Bronchitis • Otitis media • Hib vaccine – 3 doses over 2 month intervals • Greatly reduced meningitis cases
Bordetella • c.a. of whooping cough (pertussis) • Most cases occur in infants; can be fatal • Mild -> progresses to severe • Immunization @ 2-3 months; short-lived protection (up to 7 yrs) • DTaP vaccine • Diptheria toxoid • Tetanus toxoid • Acellular pertussis antigens