Lesson 8a, 8b Flashcards
Act as adhesins in E. coli facilitating attachment to mucosal surfaces
Proteinaceous fimbrial (F)
Give three parts of the E. coli that can be utilized as antigens for serotyping E. coli
Somatic (O), flagellar (H) capsular (K) antigens
Give the virulence factors of pathogenic strains of E. coli
- capsules
- endotoxins
- adherence and colonization
- enterotoxin
Interfere with the phagocytosis and with the antibacterial effectiveness of the complement system
Capsule
Released upon lysis or death of the bacteria then produce fever, DIC, endotoxic shock
Endotoxin
Allow attachment to mucosal surfaces and facilitates colonization by reducing the expulsive effects of peristalsis and the flushing effect of urine
Fimbrial adhesins
What is the most common adhesin present in strains of E. coli infecting pigs
K88
E. coli adhesins present in calves
F41
E. coli adhesins in calves and lambs
K99
Adhesins found only in older piglets due to lack of receptors in younger piglets
F18
These E. coli strains are important in post-weaning diarrhea and edema diseases in older piglets
F18+
An adhesin associated with attaching and effacing E. coli
Intimin
These E. coli are adhere to the host epithelial cell membrane with marked rearrangement of the cytoskeleton
Attaching and effacing E. coli (AEEC)
Derivatives of endotoxins of E. coli
- enterotoxin
- shigatoxins
- verotoxins
- cytotoxic necrotizing factors
What type of enterotoxin is common in pigs and induces hypersecretion of fluid into the intestine through stimulation of adenylate cyclase activity?
LT1
Heat labile enterotoxin demonstrated in some ETEC strains isolated from cattle?
LT2
This toxin produced by E. coli influence fluid and electrolyte secretion of the small intestine and inhibits fluid absorption
STa (heat-stable enterotoxin)
Which heat-stable toxin of E. coli causes secretion of chloride and bicarbonate ions and inhibit sodium absorption?
STb
STa of E. coli cause diarrhea through increasing ____ _____
guanosine monophosphate
Common under intensive systems of management due to build-up of infection in the environment
enteric colibacillosis
endotoxins produced during enteric colibacillosis
LT and STa
Which fimbrial adhesins are important for neonatal diarrhea in case of enteric colibacillosis?
K88 and K99
Common under intensive systems of management due to build-up of infection in the environment affecting newborn calves, lambs and piglets
Enteric colibacillosis
In poultry, colisepticaemia is referred to as _____ characterized by chronic inflammatory changes resembling tuberculous lesions
Coligranuloma (Hjarre’s disease)
Occurs 1 to 2 weeks after weaning in rapidly growing pigs
Edema disease of pigs
Which toxin is produced by noninvasive E.coli that damages endothelial cells with consequent perivascular edema?
ST2e
What disease is produced by isolated noninvasive E. coli strains which replicate in the tract and produce a shigatoxin (ST2e)
edema disease of pigs
Occurs within a week or two after weaning, after changes in feeding regimens or in management and with possible
involvement of rotaviruses
Post-weaning diarrhea of pigs
Majority outbreaks of post-weaning diarrhea in pigs are associated with?
Enterotoxigenic E. coli (ETEC)
Infection of the mammary glands of cows and sows by members of the Enterobacteriaceae, including E. coli
Coliform mastitis
In E. coli infections, specimens cultured on blood and MacConkey agar are incubated aerobically at what temp. and how many hours
37°C for 24 to 48 hours
The colonies of some E. coli strains have a ______ on EMB agar
metallic sheen
On _______, colonies of E. coli are bright pink
MacConkey agar
On ______, colonies of E. coli are greyish, round and shiny with a characteristic smell
Blood agar
Enterotoxins in the small intestine can be detected, using methods employing ______
Monoclonal antibodies
For expression of fimbrial antigens, isolates should be subcultured on?
Minca medium
Identify the 3 major enteric and systemic pathogens
Escherichia coli
Salmonella serotypes
Yersinia species
Name atleast 3 opportunistic pathogens of Enterobacteriaceae
Proteus species
Enterobacter species
Klebsiella species
Give at least 2 non-pathogenic enterobacteriaceae
Hafnia sp. and Erwinia sp.
Formerly used to describe enterobacteria capable of fermenting lactose
Coliform
