Flashcards in Exam 2: E. coli - A. Lignieresii Deck (160)
Where does Enterobacteriaceae reside?
the GI tract of humans and animals
Is lipid A an endotoxin or exotoxin? What type of bacteria is it found in?
endotoxin, in gram negative bacteria
Is enterobacteriaceae gram positive or negative? Is it an aerobe or anaerobe?
gram negative, facultative anaerobe
Why is coliform enumeration performed?
to evaluate fecal/sewage contamination
What are the most common nosocomial infections? Are these obligate or opportunistic pathogens?
Klebsiella pneumonia, Klebsiella oxytoca, Enterobacter cloaca, Enterobacter aerogenes, Proteus mirabilis, and Citrobacter freundii. These are opportunistic pathogens.
What is a serotype? What do O, H, F, and K represent?
complete antigenic formula. O-antigen, H-Flagella, F-fimbriae, K-capsule.
Is Shigella spp. also considered and Escherichia?
Yes, but it is not present in animals.
What are ExPEC E. coli strains? What do they affect?
Extra-intestinal pathogenic strains. They affect resp., septicaemiae, UTI, mastitis
What are the 5 main enteric pathotypes of E. coli?
ETEC - enterotoxigenic, EHEC - enterohemorrhagic, VTEC/STEC - verotoxigenic/shiga-like toxic, EPEC - enteropathogenic, and RPEC - rabbit pathogenic.
What are the 4 main types of E. coli extra intestinal pathotypes? Who do each affect?
APEC - avian pathogenic, NTEC (necrotoxigenic) - cattle, Mastitis causing E. coli - cattle, and MMA in pigs.
What causes bacterial diarrhea in piglets?
ETEC and EPEC
T/F: Bacterial diarrhea in fattening pigs, sows, and boar is always caused by E. coli
False. It is seldom caused by e. coli
Which ETEC adhesion factor is seen in neonates->post weaning pigs and is expressed at body temp?
What ETEC adhesion factor is in both pigs and bovines, and expression is temperature dependent?
Which ETEC adhesion factor is mainly extrachromosomal and seen only in neonates?
Which enterotoxin is seen in ETEC, EPEC, and VTEC, and is also closely related to STa?
What are the clinical signs of ETEC?
animals remain drinkin, have smelly feces, and are dehydrated. Older animals have white-grey diarrhea that isn't as watery.
What is the ideal way to prevent ETEC?
keep infection pressure low and maternal immunity high by vaccines, hygiene, and selecting receptor free piglets.
Which E. coli strain causes oedema disease? In what age group?
VTEC, in post weaning
What are the VTEC virulence factors?
adhesion (F18), exotoxin (VT2e or Stx2e), and endotoxin which causes acute mortality
What are the clinical signs of VTEC?
acute mortality (some), diarrhea (some), anorexia, oedema (especially swollen eyelids), and CNS.
What is the course of treatment for VTEC affected animals?
fast them to eliminate the toxin, antimicrobial therapy after susceptibility testing (because of resistance).
T/F: You want to vaccinate and castrate piglets at the same time.
False. You want to keep stress levels to a minimum in order to prevent VTEC.
Which is the most important pathogen in UTIs in pigs?
T/F: Septicaemiae caused by E. coli us secondary to enteric infection.
True. It is rarely a primary disease.
What are the E. coli diseases in bovines and what age groups do they affect?
ETEC - animals less than 3 days of age, EPEC and EHEC - animals older than 1 week, Septicaemic (NTEC) - neonates, lack of colostrum.
Which is the most common virulence factor in ETEC in bovines?
T/F: EHEC and EPEC are both zoonotic.
False, only EHEC is.
Which are the most frequent E. coli serotypes in poultry and other birds?
O1, O2, and O78