Yersinia Seo

Question 1

Yersinia Pestis

Answer 1

causes plague

Question 2

Causes an endemic disease in what animals

Answer 2

voles and deer mice

Question 3

accidental animal hosts

Answer 3

• cattle, horses, swine, and sheep are not susceptible

- wild and domestic cats can acquire infection by ingesting infected rodents

Question 4

Disease in cats

Answer 4

• the bubonic plague is most common
• Lymphadenitis
• in cats it is often fatal
• suspected cases in cats should be placed in isolation and reported to CDC

Question 5

Disease in humans

Answer 5

• Bubonic plague (most common)
• Pneumonic plague
• Pneumonic plague is the most serious form of disease and is the only form of plague that can be spread from person to person
• Septicemic plague, a progression from either bubonic or pneumonic plague

Question 6

Transmission

Answer 6

• Infected flea bites (referred to as sylvatic plague), which usually result in bubonic plague
• From infected cats through scratches or bite
• People or cats infected with pneumonic plague shed Y. pestis through sputum or respiratory droplets and can directly spread this form from human to human

Question 7

Flea transmission

Answer 7

• Spread through infected oriental rat fleas (Xenopsylla cheopis), which feed primarily on rats and other rodents
• Cat and dog fleas do not transmit Y. pestis efficiently

Question 8

Pathogenesis

Answer 8

• Phagosome-lysosome fusion occurs, but Y. pestis is able to survive
• type III secretion system
• Released Yops also trigger apoptosis of macrophage
• Type III secretion system injects Yops directly into phagocytes to inhibit phagocytosis and proinflammatory cytokine release, and apoptosis is induced

Question 9

Yersinia pseudotuberculosis

Answer 9

an enteropathogen of wild and domestic animals in all continents.

Question 10

Yersinia pseudotuberculosis

disease

Answer 10

• Fecal-oral route
• The acute form is characterized by bloody, mucous diarrhea (gastroenteritis especially termial ileum) with death within 24-48 hours
• The chronic form is characterized by caseous abscesses form in intestinal wall, mesenteric lymph nodes, liver, and spleen (similar to tuberculosis).
• Gregarious wild birds (such as blackbirds, grackles, and starlings) and rats are important reservoirs.
• Cats are the most commonly infected domestic mammal, especially adult rural outdoor cats
• Y. pestis, disease is usually limited to gastroenteritis

Question 11

Yersinia pseudotuberculosis

pathogenesis

Answer 11

• Y. pseudotuberculosis also has three adhesins that adhere to luminal surface of M cells and basolateral surfaces of ileal enterocytes: Ail, Inv, and Yad
• Y. pseudotuberculosis passes through M cells; after that, pathogenesis is very similar to Y. pestis
• Facultative intracellular parasite of macrophages
• Diarrhea is the result of prostaglandin synthesis from recruited neutrophils

Question 12

Yersinia pseudotuberculosis

diagnosis

Answer 12

Culture from feces or lymph node aspirates; can be benefited by cold enrichment at 4 degrees C for several weeks

Question 13

Yersinia enterocolitica

transmission

Answer 13

• Widespread in the environment
• Swine are important carriers
• One of the major sources of human infection with serobiotype O: 3/4 is through the handling of swine and consumption of pork

Question 14

Yersinia enterocolitica

disease

Answer 14

Gastroenteritis (bloody diarrhea), ileitis, and mesenteric adentitis in people and animals; pseudoappendicitis In people.

Question 15

Yersinia enterocolitica

pathogenesis

Answer 15

• Invasion through M cells

- Initially it is an intracellular pathogen in macrophages, then it becomes extracellular

Question 16

Yersinia ruckeri

Answer 16

• Enteric red-mouth diesease of salmon and trout
• Transmitted through direct contact or through fomites
• Hemorrhagic septicemia
• Hemorrhages on body surface, characteristically around mouth
• Rainbow trout most susceptible