Yersinia
المؤلف:
Cornelissen, C. N., Harvey, R. A., & Fisher, B. D
المصدر:
Lippincott Illustrated Reviews Microbiology
الجزء والصفحة:
3rd edition , p123-125
2025-07-09
625
The genus Yersinia includes three species of medical importance: Yersinia enterocolitica and Yersinia pseudotuberculosis, both potential pathogens of the GI tract that are discussed in this chapter, and Yersinia pestis, the etiologic agent of bubonic plague. Y. enterocolitica and Y. pseudotuberculosis are both motile when grown at 25oC but not at 37oC. Multiple serotypes of both species exist, and, as with Y. pestis, the type III secretion system and Yop proteins are virulence factors for avoidance of phagocytosis. In contrast to most pathogenic Enterobacteriaceae, these strains of Yersinia grow well at room temperature as well as at 37oC. Most strains are Lac–.
A. Pathogenesis and clinical significance
Infection occurs via ingestion of food that has become contaminated through contact with colonized domestic animals, abattoirs, or raw meat (especially pork). Y. enterocolitica is a relatively uncommon cause of enterocolitis in the United States, and Y. pseudotuberculosis is even rarer. Infection results in ulcerative lesions in the terminal ileum, necrotic lesions in Peyer patches, and enlargement of mesenteric lymph nodes. Enterocolitis caused by Yersinia is characterized by fever, abdominal pain, and diarrhea. When accompanied by right lower quadrant tenderness and leukocytosis, the symptoms are clinically indistinguishable from appendicitis. Symptoms commonly resolve in 1 to 3 weeks. Sequelae may include reactive poly arthritis and erythema nodosum. Other, less common clinical presentations include exudative pharyngitis and, in compromised patients, septicemia.
B. Laboratory identification
Yersinia can be cultured from appropriate specimens on MacConkey or cefsulodin-irgasan-novobiocin (CIN, a medium selective for Yersinia) agars. Identification is based on biochemical screening. In the absence of a positive culture, serologic tests for anti-Yersinia antibodies may assist in diagnosis.
C. Treatment and prevention
Reducing infections and outbreaks rests on measures to limit potential contamination of meat, ensuring its proper handling and preparation. Antibiotic therapy (for example, with ciprofloxacin or trimethoprim-sulfamethoxazole) is essential for systemic disease (sepsis), but is of questionable value for self-limited diseases such as enterocolitis (Figure 1).
Fig1. Summary of Yersinia enterocolitica disease. 1 Indicates first-line drugs.
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