Yersinia

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.

Review Questions

• What diseases are caused by Yersinia pestis?
• How does Yersinia enterocolitica typically transmit to humans?
• What virulence mechanism allows Yersinia species to evade the host immune system?

Related terms

Proteobacteria: A major phylum of Gram-negative bacteria that includes a wide variety of pathogens.

Type III Secretion System: A needle-like protein appendage used by some bacteria to inject toxins into host cells.

Gastroenteritis: Inflammation of the stomach and intestines typically caused by infection leading to symptoms like diarrhea and vomiting.