Yersinia Flashcards Preview

RUSVM Bacteriology Gram Negatives > Yersinia > Flashcards

Flashcards in Yersinia Deck (33):
1

Yersinia description

Gram negative, lactose negative, bipolar staining in smears, most motile (except Y. pestis)

2

Yersinia Important species

Y. ruckeri (fish) - enterocolitica (domestics & primates) - pseudotuberculosis (birds,rodents, domestics, primates) - **Y. pestis (Plague! zoonosis, rodents, cats)

3

Yersinia pestis - Most known as

The bubonic plague! Bioweapon - Rodent based zoonotic disease

4

Yersinia pestis Presentations

Local lymphadenitis (bubonic plague) - Pneumonia (pneumonic plague, 50% fatal) - Septicemia (septicemic plague, fatal if untreated)

5

Yersinia pestis virulence factors

Incomplete LPS (no O-Ag) - Pla - Hms - Yops & LcrV - Ymt - Gsr

6

Pla

enhace visceral colonization, bacterial metastasis

7

Hms

Iron acquisition, colonization of flea proventriculus***

8

Yops & Lcrv

Effector proteins act as toxins

9

Ymt

protects bacteria from digestive enzymes in flea

10

Gsr

Survival of bacteria in phagolysosome in macrophages

11

Yersinia pestis reservoir

Rodents! Endemic areas: intermediate hosts- squirrels, prairie dogs, rats, rabbits

12

Yersinia pestis Transmission

Fleas, airborne, oral

13

Yersinia pestis pathogenesis

**First intracellular, then extracellular*** Fleas feed--> bacteria blocks proventriculus & contaminates feeding site --> bacteria killed at sige by PMNs & inflammation --> some survive in macrophages--> induce apoptosis--> secrete proteins --> further survival--> extracellular survival

14

Yersinia pestis in humans

Traced to feline infection - 15% fatality with treatment - Inoculation via cuts, bites, scratches, airborne, flea borne, ingestion of infected meat or necropsy exposure

15

Yersinia pestis in cats

Ingest infected prey - Regional lymphadenitis - Symptomatic cases are fatal - Cat & dog flease (Ctenocephalides) doesn't transmit bacteria (no proventricular blockage)

16

Yersinia pestis Culture

Blood or chocolate agar, stain with Wayson's or gram stain

17

Yersinia pestis treatment

Report suspected feline plague!! (isolate, treat for fleas) no vaccines

18

Yersinia pseudotuberculosis

Worldwide - cold months - Birds & rodents, occasionally cats

19

Yersinia pseudotuberculosis in birds & rodents

Mesenteric lymphadenitis - terminal ileitis - acute gastroenteritis - septicemia

20

Yersinia pseudotuberculosis virulence factors

Ail - Inv * Yad - Very similar to Y. pestis

21

Yersinia pseudotuberculosis Ail

Adhere M cells, protects from complement

22

Yersinia pseudotuberculosis Inv & Yad

Adherence to M cells & basolateral ileal epithelial cells - Yad protects from complemen

23

Yersinia pseudotuberculosis pathogenesis

Similar to pestis - Intracellular then Extracellular

24

Yersinia pseudotuberculosis disease patterns

Diarrhea (PMN recruitment & PG release) - Septicemia (immune system exhausted during local phase) - Necrosis of intestinal wall, abdominal lymph nodes, visceral organs

25

Yersinia pseudotuberculosis immunity

Natural infection leads to immunity - Avirulent live vaccines are protective but not available - Responds to same antimicrobials as Y. pestis

26

Yersinia enterocolitica species affected & disease pattern

Domestics & primates - Mesenteric lymphadenitis, terminal ileitis, acute gastroenteritis, septicemia

27

Yersinia enterocolitica virulence factors

Yst - Yersinia stable toxin - unique - Open Cl channels for secretion & diarrhea

28

Yersinia enterocolitica variability

2 subspecies, >70 serotypes from O antigen, 6 biogroups based on enzymatic reactivity

29

Yersinia enterocolitica pathogenesis

same as Y. pseudoTB - Addition of Yst induced diarrhea (more adapted to extracellular existence) - Most infections are self-limiting

30

Yersinia enterocolitica fastidious-ness

Requires cold enrichment - special culture media

31

Yersinia enterocolitica treatment

Fluoroquinolones, tetracycline etc (resistant plasmids to tetracycline & streptomycin are common)

32

Yersinia ruckeria

"Enteric redmouth - Rainbow trout - Hemorrhagic inflammation of perioral area - mortalities in hatcheries - Outbreaks controled with sulfonamides, tetracyclin etc. - Some sulfa bacterin vaccine help

33

If I say enteric redmouth of trout, you say...

Yersinia ruckeria