Yersinia spp.

Question 1

Yersinia spp.

Morphology

Answer 1

Gr- rods, non-spore forming
O & H

Question 2

Yersinia spp.

Antigenic structure

Answer 2

LPS - O and H - flagella

Question 3

Yersinia spp.

Diagnostic characteristics

Answer 3

Motile (25°, not 37°)
Glu fermenter & NON-lactose fermenter
urease +
catalase + and oxidase -

Question 4

Yersinia eneterocolitica

Yersinia pathogenesis (transmission)

Answer 4

Fecal-oral (& contaminated food/water)
invasion of M cells –> T3 secretion system to phagocytic cells, secreting YOP (Y. outer membrane protein) –> disruption of host’s actin filaments –> cytotoxic effects on phagocytic cell –> apoptosis of macrophages & inactvaito of phagocytosis proteins –> evasion/killing of phagocytes –> Y. spp multiplication, inflammation & ulceration –> microabcesses and leukocyte appearance in feces.
Extension to mesenteric lymph nodes –> specific symptoms

Question 5

Yersinia enterocolitica

Symptoms (early & late)

Answer 5

Early: fever, abdominal pain, diarrhea (watery to bloody), mesenteric adenitis or terminal ileitis.
late: (1-2weeks after onset of diarrhea) arthalgia, arthitis and erythema nodosum

Question 6

Yersinia eneterocolitica

Prophylaxis & treatment

Answer 6

1. non-specific
2. antibiotics and symptomatic

Question 7

Yersinia enterocolitica

Incubation & invasion factors

Answer 7

Incubation: 3-7days
Invasion: urease, lecithinase, hyaluronidase & invasin