Exam 3: Yersinia Flashcards
What does Yersinia pestis cause?
Plague
What is Yersinia pestis endemic in?
Voles and deer mice, which usually do no have serious disease
What animals are not susceptible to Yersinia pestis?
Cattle
Horses
Swine
Sheep
How can wild and domestic cats acquire Yersinia pestis infection?
By ingesting infected rodents
What is the most common disease in cats due to Yersinia pestis?
Bubonic plague
What is a clinical sign of disease in cats casued by Yersinia pestis?
Lymphadenitis
What is often the result of disease in cats from Yersinia pestis?
Death
What should be done with suspected cases of Yersinia pestis in cats?
They should be placed in isolation and reported to CDC
What human diseases can occur with Yersinia pestis?
Bubonic plague (most common)
Pneumonic plague
Septicemic plague
Describe pneumonic plague
Thee most serious form of disease and is the only form of plague that can be spread from person to person
What can septicemic plague result from?
As a progression from either bubonic or pneumonic plague
What is the transmission of Yersinia pestis?
Infected flea bites (sylvatic plague), which usually result in bubonic plague
From infected cats through scratches or bites
Pneumonic plague shed Y. pestis through sputum or respiratory droplets and can directly spread this form from human to human
What is flea transmission of Y. pestis spread through?
Infected oriental rat fleas, which feed primarily on rats and other rodents
Do cat and dog fleas transmit Y. pestis efficiently?
No
What is the pathogenesis of Y. pestis?
Phagosome-lysosome fusion occurs, but Y. pestis is able to survive
What triggers the apoptosis of macrophage with Y. pestis?
Released Yops
How is apoptosis induced with Y. pestis?
Type 3 secretion system injects Yops directly into phagocytes to inhibit phagocytosis and proinflammatory cytokine release, and apoptosis is induced
What is Y. pseudotuberculosis?
An enteropathogen of wild and domestic animals
How is Y. pseudotuberculosis transmitted?
By the fecal-oral route
What is the acute form of Y. pseudotuberculosis characterized by?
Bloody, mucous diarrhea with death within 24-48 hours
What is the chronic form of Y. pseudotuberculosis characterized by?
Caseous abscesses form in intestinal wall, mesenteric lymph nodes, liver, and spleen
What are important reservoirs of Y. pseudotuberculosis?
Gregarious wild birds (such as blackbirds, grackles, and starlings) and rats
What domestic mammal is the most commonly infected with Y. pseudotuberculosis?
Cats, especially the adult rural outdoor cat
What is different about Y. pseudotuberculosis compared to Y. pestis?
Disease is usually limited to gastroenteritis
Describe the pathogenesis of Y. pseudotuberculosis
It has 3 adhesins that adhere to luminal surface of M cells and basolateral surfaces or ileal enterocytes: Ail, Inv, and Yad
It passes through M cells and then the pathogenesisi is very similar to Y. pestis
Describe the association of Y. pseudotuberculosis and macrophages
It is a facultative intracellular parasite of macrophages
What is diarrhea the result of with Y. pseudotuberculosis?
Prostaglandin synthesis from recruited neutrophils
How is Y. pseudotuberculosis diagnosed?
Culture from feces or lymph node aspirates
Can be benefited by cold enrichment at 4 degrees C for several weeks
What is an important carrier of Y. enterocolitica?
Swine
What is one of the major sources of human infection with Y. enterocolitica serobiotyoe O?
Through the handling of swine and consumption of pork
What are the clinical signs of Y. enterocolitica?
Gastroenteritis (bloody diarrhea), ileitis, and mesenteric adenitis in people and animals
Pseudoappendicitis in people
What is the pathogenesis of Y. enterocolitica?
Invasion through M cells
Intracellular pathogen in macrophages, then it becomes extracelluilar
What is Y. ruckeri?
Enteric red-mouth disease of salmon and trout
What is Y. ruckeri transmitted through?
Direct contact or through fomites
What does Y. ruckeri cause?
Hemorrhagic septicemia
What is a clinical sign of hemorrhagic septicemia?
Hemorrhages on body surface, characteristically around mouth
What is the most susceptible animal to Y. ruckeri?
Rainbow trout
