Difference between revisions of "Yersinia"
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*Cause disease in animals and are important zoonoses | *Cause disease in animals and are important zoonoses | ||
| + | *10 species of which ''Yersinia pestis, Yersinia pseudotuberculosis amd Yersinia enterocolitica'' are pathogenic to animals and humnans | ||
| + | *Rodents provide a reservoir of ''Yersinia pestis'', which is the cause of human plague; fleas transmit the infection to other animals and humans | ||
| + | *''Yersinia pseudotuberculosis and enterocolitica'' reside in the intestine of domestic and wild animals and birds | ||
| + | *Birds may cause mechanical transfer of the organisms | ||
===Characteristics=== | ===Characteristics=== | ||
| − | *Enterobacteria, but grow more slowly and at lower temperatures than other enterobacteria | + | *Enterobacteria, but grow more slowly and at lower temperatures than other enterobacteria |
| + | *Gram negative, non-spore forming, facultative anaerobes - rods or colibacilli | ||
*Non-lactose fermentors | *Non-lactose fermentors | ||
| − | * | + | *Facultative intracellular pathogens |
| + | *Show bipolar staining in Giemsa-stained smears from animal tissue | ||
| + | *Pathogenic strains identified by serotyping and biotyping | ||
===Pathogenesis=== | ===Pathogenesis=== | ||
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*Survive in phagolysosomes and do not interfere with degranulation or lysosomal fusion | *Survive in phagolysosomes and do not interfere with degranulation or lysosomal fusion | ||
*Resistant to macrophage killing mechanisms | *Resistant to macrophage killing mechanisms | ||
| − | *The bacteria destroy | + | *The bacteria destroy macrophages in lymph nodes, liver and spleen, causing septicaemia |
===Clnical infections=== | ===Clnical infections=== | ||
Revision as of 12:46, 9 February 2008
- Cause intestinal disease
Overview
- Cause disease in animals and are important zoonoses
- 10 species of which Yersinia pestis, Yersinia pseudotuberculosis amd Yersinia enterocolitica are pathogenic to animals and humnans
- Rodents provide a reservoir of Yersinia pestis, which is the cause of human plague; fleas transmit the infection to other animals and humans
- Yersinia pseudotuberculosis and enterocolitica reside in the intestine of domestic and wild animals and birds
- Birds may cause mechanical transfer of the organisms
Characteristics
- Enterobacteria, but grow more slowly and at lower temperatures than other enterobacteria
- Gram negative, non-spore forming, facultative anaerobes - rods or colibacilli
- Non-lactose fermentors
- Facultative intracellular pathogens
- Show bipolar staining in Giemsa-stained smears from animal tissue
- Pathogenic strains identified by serotyping and biotyping
Pathogenesis
- Invasive Yersinia grow inside macrophages
- Survive in phagolysosomes and do not interfere with degranulation or lysosomal fusion
- Resistant to macrophage killing mechanisms
- The bacteria destroy macrophages in lymph nodes, liver and spleen, causing septicaemia