PetriKey

Bacterium

Francisella tularensis

Tularemia, rabbit/tick zoonosis, cysteine need

fran-sih-SEL-uh too-lah-REN-sis

Gram negativegram-negativecoccobacilluszoonosisintracellulartick-borneselect-agent

High-yield clue

Tularemia ('rabbit fever') is a fastidious, cysteine-requiring intracellular coccobacillus spread by ticks, deerflies, and rabbit contact.

Overview

A highly infectious, fastidious Gram-negative coccobacillus that is a facultative intracellular pathogen and the cause of tularemia, a high-yield zoonotic select-agent study organism.

Classification

  • Gram-negative
  • Coccobacillus
  • Francisellaceae
  • Aerobe
  • Facultative intracellular

Lab & identification clues

  • Cysteine-requiring growth vocabulary
  • Fastidious, slow-growing concept
  • Very low infectious dose vocabulary
  • Serology-based identification concept

Associations

  • Ticks, deerflies, and rabbit/rodent contact vocabulary
  • Ulceroglandular presentation vocabulary
  • Category A select-agent and aerosol-risk framing

Commonly confused with

  • Yersinia pestis
  • Brucella species

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