Escherichia coli - GI infections and disease Flashcards
Where is E. coli found?
gut microbiome of mammals
How is E. coli transmitted?
fecal-oral transmission
What are the enteric pathotypes of E. coli?
Enterotoxigeneic (ETEC)
Enteropathogenic (EPEC)
Shiga toxin-producing (STEC)
What are the extraintestinal pathotypes of E. coli?
Avian pathogenic (APEC)
Septicemic (SEPEC)
Uropathogenic (UPEC)
Describe the virulence factors of E. coli
adhesins
exotoxins
endotoxins
Describe the exotoxins of E. coli
enterotoxins - enterocyte hypersecretion and malabsorption
shiga toxins - damage to enterocytes and endothelial cells
cytotoxins - secreted by extraintestinal pathotypes
What are the important reservoirs of infection with E. coli?
carriers
How are young animals predisposed to infection and disease?
overcrowding & poor hygiene
stress
insufficient colostral immunity
Where do Enterotoxigenic (ETEC) strains infect?
jejunum & ileum
Who does ETEC primarily infect?
young piglets, calves, lambs
Where do Enteropathogenic (EPEC) strains infect?
ileum & colon
what can cause post weaning diarrhea in pigs?
ETEC and sometimes EPEC strains
what are clinical signs with post-weaning diarrhea in pigs? (mild and severe)
mild - reduced feed intake, watery diarrhea
severe - profuse watery diarrhea, bluish-red skin ears, sudden death
what causes edema disease in swine?
Shiga toxin producing (STEC)
Describe pathogenesis of STEC strains
Shiga toxin > BS, damages endothelial cells > perivascular edema
what is this pig infected with?
STEC E. coli
what are the factors contributing to edema disease in swine?
multifactorial etiology - new social and physical environments, dietary changes, loss of colostrum, etc.
what causes Colisepticemia in mammals?
Septicemic (SEPEC) strains
what animals primarily get Colisepticemia?
newborn ruminants
How do septicemic strains cause disease?
colonize and cross mucosae or invade via infected naval
endotoxin > endotoxic shock, high mortality
How is SEPEC bacteria excreted?
feces, urine, and oral & nasal secretions
what causes Colisepticemia in poultry?
Avian pathogenic (APEC) strains
How do Avian pathogenic (APEC) strains cause disease?
colonize & breach respiratory mucosa via inhalation of aerosolized dried feces
what are the factors contributing to Colisepticemia in poultry?
multifactorial etiology - stressful housing conditions + other respiratory pathogens > inc susceptibility to infection & disease
What does colisepticemia in poultry cause? What age?
acute septicemia & sudden death
primarily in birds <1 month old
what causes urogenital tract infections?
Uropathogenic (UPEC) strains
what population does UPEC strains primarily infect?
dogs and cats
what is the biggest risk of pyometra?
potentially fatal
what causes coliform mastitis?
no pathotype characterized
what population does coliform mastitis affect?
older, multiparous cows
How does coliform mastitis cause disease?
fecal contamination of skin of mammary gland > rapid growth in udder> endotoxin> local inflammation, systemic illness
which form of coliform mastitis has a high rate of spontaneous cure?
moderate coliform mastitis - slightly swollen quarter producing watery to serous secretion w/ flakes
what type of mastitis is coliform mastitis?
environmental - fecal contamination
What is the range of disease seen with Coliform mastitis?
subclinical infecto to severe (fatal) systemic disease
How is E. coli diagnosed?
clinical signs, history, age group
ID and culture
How is E. coli prevented and controlled?
hygiene
reduce stress
feed colostrum
manage dietary changes
breed for resistance
vaccinate
Which diseases can you vaccinate for?
enteric colibacillosis, edema disease, post-weaning diarrhea, E. coli mastitis
How is E. coli treated?
none of its bolded sooo…..
