Enterobacteriaceae Flashcards
family characteristics
- rod shaped
- facultative anaerobes
- gram negative
- don’t form spores
- can have capsule, can produce exotoxins (enterotoxins)
- ferment sugar
genus: escherichia, species: escherichia coli basic info
- found in intestinal tract of all warm blooded animals (absent in fish, cold blooded)
- gram neg, short rods
- peritrichous flagella, capsule, no spores
- ferments lactose!!
4 types of diseases caused by e coli
- enterotoxic
- enterotoxemia
- local invasive
- septicemic form
enterotoxic (enteric colibacillosis) e coli
lumen of small intestine –> enterotoxin –> fluid secretion –> diarrhea –> enterotoxin unnecessary
enterotoxemic e coli (colibacillosis)
small intestine –> toxin –> absorption of toxin –> action of toxin elsewhere
local invasive e coli (colibacillosis)
local invasion and destruction of intestinal epithelium –> not enterotoxigenic, do not become bacteremic
septicemic e coli (colibacillosis)
- bacteremia or extraintestinal localization of e coli with endotoxin mediated damage
- entry through respiratory tract or intestine
e coli and endotoxins
- part of the outer layer of the cell wall
- released in soluble form during bacterial growth, liberated when bacteria lyse
- less toxic than exotoxins
- leukopenia, hypotension, complement activation, intravascular coagulation, death
e coli and exotoxins
- called enterotoxins
- activate adenylate cyclase –> increased cAMP
- hypersecretion of water –> fluid loss
2 forms of e coli in cattle
- septicemic (very severe, young age)
- enteric (intestinal issues)
e coli infections in cattle
- septicemic colibacillosis or coli septicemia
- 4-5 day old calves
- acute –> no scouring, no fever (overwhelming)
- enteric –> calves under 2 weeks, up to 1 month (diarrhea)
importance of colostrum to calves and e coli
- colostrum may inhibit the sudden and abnormal rate of multiplication of e coli
- should receive 5% of body weight within first 12 hours of birth, repeat 18-20 hours
mastitis
- e coli associated with acute mastitis
- poor sanitation
- one or more quarters –> high temp, drop in milk production
e coli in dogs/cats
commonly isolated pathogen in urinary tract infections, pyometra
e coli infection in pigs (young)
- susceptible in first 14 weeks of age
- neonatal colibacillosis/piglet scours (1-12d old)
- diarrhea, dehydration –> high mortality
- diagnose with cultures from SI/LI
e coli causing edema disease in pigs
- occurs 1 week after weaning
- acute, highly fatal neurologic disorder
- associated with dietary changes
- dependent on colonization of SI –> toxin produced (hemolysin, K88 pili antigens) –> arterial degeneration, vascular permeability
control of e coli in pigs
- sanitation
- immunization of sows
- electrolytes as supportive therapy
- determine sensitivity to antibiotics
3 types of e coli infection in poultry (colisepticaemia)
- neonatal colisepticaemia
- respiratory colisepticaemia
- enteric colisepticaemia
neonatal colisepticaemia
- chicks within 2 days of hatching
- high mortality, stunting
- darkened lungs, splenomegaly, pericarditis, pleuritis, peritonitis, air sacculitis
- yolk sac infection from pores in egg
respiratory colisepticaemia
- access the bloodstream after crossing damaged respiratory tract lining or epithelium
- tracheitis, bronchitis, pneumonia, air sacculitis, pericardits, peritonitis
- air sacs thicken –.> fibrinous forms
enteric colisepticaemia
- sequel to something that has damaged lining of digestive tract
- main lesion is liver congestion
- internal lesions similar to respiratory colisepticaemia
egg peritonitis
- e coli can contribute
- yolk debris, insippated tolk, caseous material
- inflammation of ovaries (salpingitis)
- some deaths
what else can e coli contribute to (3)
- synovitis
- joint infections - arthritis
- septicemic conditions
are there vaccines for e coli
yes –> given to pregnant female cows and pigs
e coli in humans
- O157:H7
- intestines of healthy cattle and on udders
- infants, elderly especially susceptible
- diarrhea, UTIs
- hemolytic uremia syndrome, kidney failure
e coli O157:H7 in animals
not perceived as an animal health pathogen
e coli in lambs
- enteritis
- vulnerable in first 2 days of life especially
- mild: scouring, sickness
- severe: toxemia, lameness, diarhea
genus: enterobacter
- lactose fermenter, non-hemolytic
- cause opportunistic infections in immunocompromised hosts
- mastitis, uterine infections (horses), bacterimia (humans)
genus: klebsiella
- lactose fermenter, non-hemolytic
- opportunistic pathogen
- capsule
- mastitis (cow), cervicitis and metritis (mares), UTIs, pneumonia (humans), cystitis (dogs)
genus: proteus
- lactose non-fermenter
- four species
- motile, non-hemolytic
- concentric rings on plate
- UTIs in dogs and cats
- not an enteric pathogen in animals
genus: providencia
- lactose non-fermenter
- rarely cause animal infections, not an enteric pathogen
- diarrhea in humans
genus: morganella
- lactose non-fermenter
- opportunistic pathogen
- intestinal tract of humans and animals
- not an enteric pathogen
- isolated from wound and UTIs
genus: shigella
- affects only humans and non-human primates
- dysentery
