🦠microbiology review

Yersinia

Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025

Definition

Yersinia is a genus of Gram-negative bacteria belonging to the family Enterobacteriaceae. Some species are pathogenic to humans, causing diseases such as plague and gastroenteritis.

5 Must Know Facts For Your Next Test

  1. Yersinia pestis is the causative agent of plague, including bubonic, septicemic, and pneumonic forms.
  2. Yersinia enterocolitica causes gastroenteritis with symptoms like diarrhea, fever, and abdominal pain.
  3. These bacteria are facultatively anaerobic and can grow at a wide range of temperatures, including refrigeration temperatures.
  4. Yersinia species possess virulence factors such as type III secretion systems that help them evade the host immune response.
  5. Transmission routes include ingestion of contaminated food or water for Y. enterocolitica and flea bites or direct contact with infected animals for Y. pestis.
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