Unit 2- E. coli Flashcards
E coli
Enterobacteriaceae, gram negative rod, facultative anaerobe, flagella, ferment glucose and lactose, catalase positive, gut microflora, antimicrobial resistance
E coli Surface Antigens
LPS O antigens, fimbrial F antigens, capsule K antigens, and flagellar H antigens
Peritrichous Flagella
Flagella distributed all over the body
Large Bowel E Coli
EHEC and EIEC
Small Bowel E Coli
ETEC and EPEC
ETEC
Enterotoxigenic E coli, F4, F5, F6, and F41 adhesins, attachment to small intestine, heat labile and heat stabile enterotoxin, causes watery diarrhea
Heat Labile Enterotoxin
LT, increases cAMP increasing villous secretion
Heat Stable Enterotoxin
ST, increases cGMP increasing villous secretion
Neonatal Diarrhea
ETEC causes enteric colibacillosis in calf, lamb, and piglet, treat with milk and electrolytes, control with colostrum
Post-Weaning Diarrhea
ETEC or EPEC causes watery diarrhea in piglets after weaning
EPEC
Enteropathogenic E coli, causes pedestal formation, attaching and effacing lesions, has type III secretion, and adhesin
Pedestal Formation
Loss of microvilli and rearrangement of cytoskeleon
EHEC
Enterohemorrhagic E coli with intimin, T3SS, and causes attaching and effacing lesions in large bowel, has shiga toxin
Intimin
Adhesin
Shiga Toxin
Causes hemorrhagic diarrhea and kidney failure
STEC
Shiga toxin producing E coli = EHEC
VTEC
Verocytotoxin producing E coli = EHEC
Cattle EHEC Reservoir
Do not have shiga toxin receptor allowing cells to internalize toxin, infected cows are healthy
Edema of Pigs
EHEC causes edema of eyelids, muscle tremor, squealing and snoring, and flaccid paralysis from shiga toxin in pigs
EIEC
Enteroinvasive E coli, non flagellated, enters and replicates in macrophages in colon, destroys colonic epithelium, causes watery to bloody diarrhea, animals resistant
ExPEC
Extraintestinal pathogenic E coli, septicemic, avian pathogenic, uropathogenic, and mammary pathogenic E coli
SEPEC
Septicemic E coli, invades bloodstream in newborns or immune compromised, has serum resistance, iron uptake system, fimbriae, LPS, and cytotoxic necrotizing factors
Cytotoxic Necrotizing Factors
Induces strong inflammatory response and leads to shock
SEPEC Clinical Signs
Pyrexia, depression, weakness, arthritis in calves, watery mouth and death in lambs, and pneumonia in horse dog and cat
APEC
Avian pathogenic E coli, causes systemic disease of birds, type 1 and P fimbriae, LPS, serum resistance, and aerobactin iron uptake
UPEC
Uropathogenic E coli, causes UTI, forms intracellular biofilm, type 1 pili, hemolysin, aerobactin,a nd capsule
UPEC in Dog
Cystitis, pyelonephritis, pyometra, prostatitis, females are more susceptible because bacteria enter urethra
MPEC
Mastitis from fecal contamination and relaxation of teat sphincter after milking
Mastitis Causes
E coli, Strep uberis, Staph auerus
Diagnosis
Hemolytic on blood agar, lactose fermenter on MacConkey, metallic on EMB agar, dark blue on chromogenic
IMViC Test
Positive indole, positive methyl red, negative voges-proskauer, negative citrate
Next Generation Sequencing
Multilocus sequence typing, Pulsed-field gel electrophoresis, randomly amplified polymorphic DNA
ETEC Diagnosis
Enterotoxin ELISA, virulence genes, latex agglutination for fimbrial antigens
EPEC Diagnosis
Positive urease test, virulence gene, mucosal effacement on histopath
STEC Diagnosis
Clinical findings, hemolytic, serotypes, virulence genes
SEPEC Diagnosis
Isolation from blood, colicin V plasmids
Colicin V Plasmids
Confer serum resistance
UPEC DIAgnosis
Isolation from urine, type 1 pili
Treatment
Rehydration, antibiotics
