Escherichia

Question 1

Escheria coli - General info

Answer 1

Only important pathogen - Facultative anaerobe, gram negative, motile, peritrichous flagella, fimbriae, Normal flora of GI tract

Question 2

E. coli - Transmission

Answer 2

Fecal-oral - Most don’t cause disease but can acquire pathologic genes through transduction, conjugation, transformation

Question 3

E. coli - Antigens

Answer 3

LPS - K antigen (capsule) - H antigen (flagella) - F/P antigen (adhesions)

Question 4

E. coli - Types of adhesions

Answer 4

ETEC (fimbrial) - EIEC, EAEC, AAF (aggregative adherence fimbriae) - EPEC Bfp (bundle forming pilus) EHEC (OmpA) CURLY (promote adherence to extracellular matrix proteins)

Question 5

E. coli - Enterotoxins

Answer 5

Labile - Stabile - EAST1 - Shigalike toxins - CNF (cytotoxic necrotizing factor) - Plasmid-encoded toxin

Question 6

E. coli - ETEC age disposition

Answer 6

Neonatal/weanling pigs, calves, lambs. Dogs & horses

Question 7

E. coli - ETEC -Enterotoxigenic - Virulence factors

Answer 7

Adhesions, enterotoxins (ST &/or LT)

Question 8

E. coli - ETEC Pathogenesis

Answer 8

Ingestion–> adherence–> multiplication & secretion of enterotoxins–> diarrhea, dehydration, imbalance of e’lytes –> high mortality

Question 9

E. coli - ETEC clinical signs

Answer 9

Watery NON-BLOODY diarrhea, minimal inflammatory changes

Question 10

E. coli - EPEC - Enteropathogenic

Answer 10

Oral route, diarrhea, all animals. **Attaching and Effacing lesions!!!!!!! - Collapse of microvilli in distal SI and upper LI

Question 11

E. coli - EHEC - Enterohemorrhagic

Answer 11

Attaching & Effacing lesions!! - No binding to Bfp but the OmpA - SHIGA LIKE TOXINS BLOODY/Hemorrhagic diarrhea (hemolytic uremic syndrome if systemic. Zoonotic potential)

Question 12

If I say animal has attaching & effacing lesions, shiga like toxins and bloody diarrhea involved, you say….

Answer 12

EHEC!

Question 13

E. coli - EIEC - Enteroinvasive pathogenesis

Answer 13

Ingestion–> adherence –> induction to uptake–> “RUFFLES”–> lymphatics & blood stream–> adhesins repressed–> replication & endotoxemia–> death

Question 14

When I say ruffles, you think…

Answer 14

EIEC

Question 15

E. coli - EIEC - Miscellaneous

Answer 15

Must escape phagocytosis & complement - Must acquire iron with siderophores - Hemolysins act at pericardium, peritoneal surfaces, adrenal cortices - Inflammatory changes in liver, spleen, joints, meninges

Question 16

E. coli - EAEC - Enteroaggregative

Answer 16

Diarrhea - Weaned pigs & calves - Virulenc: AAF, agg gene, EAST 1

Question 17

Edema disease in swine

Answer 17

Extensive, generalized edema!! Ansarca!! Acute, fatal “enterotoxemia” of weaned pigs - From EHEC-like bacteria - SQ & subserosal edema from SHIGA-LIKE toxin IIe - Flaccid & dilated small intestine

Question 18

When I say shiga-like toxin IIe, you say

Answer 18

Edema disease in swine!

Question 19

Colibacilosis of Fowl

Answer 19

Many forms, ages, modes of infection - Bacteria penetrates egg shell, embryonic death or soon after hatching. **Adult Fowl can have respiratory or septicemic diseases

Question 20

Culturing E. coli - Appearance on eosin methylene blue agar

Answer 20

Green metallic sheen indicates lactose fermentation

Question 21

Culturing E. coli - Appearance on TSI slant

Answer 21

Yellow butt and slant = fermented fructose & lactose, and/or sucrose

Question 22

E. coli treatment

Answer 22

TREAT THE FLUID LOSS! - antimicrobial controversial

Question 23

E. coli -prevention

Answer 23

Dam must be exposed pre-parturition, need antibodies to go into colostrum & milk - Immunization or genetically resistant strains for pigs