Escherichia Flashcards Preview

RUSVM Bacteriology Gram Negatives > Escherichia > Flashcards

Flashcards in Escherichia Deck (23):
1

Escheria coli - General info

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

2

E. coli - Transmission

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

3

E. coli - Antigens

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

4

E. coli - Types of adhesions

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

5

E. coli - Enterotoxins

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

6

E. coli - ETEC age disposition

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

7

E. coli - ETEC -Enterotoxigenic - Virulence factors

Adhesions, enterotoxins (ST &/or LT)

8

E. coli - ETEC Pathogenesis

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

9

E. coli - ETEC clinical signs

Watery NON-BLOODY diarrhea, minimal inflammatory changes

10

E. coli - EPEC - Enteropathogenic

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

11

E. coli - EHEC - Enterohemorrhagic

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

12

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

EHEC!

13

E. coli - EIEC - Enteroinvasive pathogenesis

Ingestion--> adherence --> induction to uptake--> "RUFFLES"--> lymphatics & blood stream--> adhesins repressed--> replication & endotoxemia--> death

14

When I say ruffles, you think...

EIEC

15

E. coli - EIEC - Miscellaneous

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

16

E. coli - EAEC - Enteroaggregative

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

17

Edema disease in swine

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

18

When I say shiga-like toxin IIe, you say

Edema disease in swine!

19

Colibacilosis of Fowl

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

20

Culturing E. coli - Appearance on eosin methylene blue agar

Green metallic sheen indicates lactose fermentation

21

Culturing E. coli - Appearance on TSI slant

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

22

E. coli treatment

TREAT THE FLUID LOSS! - antimicrobial controversial

23

E. coli -prevention

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