PetriKey

Bacterium

Yersinia enterocolitica

Cold-tolerant enteric rod, pseudoappendicitis

yer-SIN-ee-uh en-ter-oh-koh-LIT-ih-kuh

Gram negativegram-negativerodentericzoonosisfoodbornepsychrophile

High-yield clue

Cold-tolerant (grows at 4C) enteric rod linked to pork and causing right-lower-quadrant pseudoappendicitis vocabulary.

Overview

A Gram-negative enteric rod that grows at refrigeration temperatures and is a study example of foodborne enterocolitis with mesenteric lymphadenitis that mimics appendicitis.

Classification

  • Gram-negative
  • Coccobacillus/rod
  • Enterobacterales
  • Facultative anaerobe
  • Psychrotolerant

Lab & identification clues

  • Cold enrichment growth vocabulary
  • Motile at 25C, non-motile at 37C concept
  • Urease positive vocabulary
  • Bipolar staining teaching note

Associations

  • Contaminated pork and dairy transmission vocabulary
  • Pseudoappendicitis presentation vocabulary
  • Reactive arthritis association concept

Commonly confused with

  • Yersinia pestis
  • Campylobacter jejuni

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource