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