PetriKey

Bacterium

Capnocytophaga species

Capnophilic gliding rod of dog and human oral flora

kap-no-sy-TOFF-uh-guh

Gram negativegram-negativerodcapnophiliczoonosisfastidiousoral-flora

High-yield clue

Fulminant sepsis after a dog or cat bite in an asplenic or immunocompromised person is the classic C. canimorsus study clue.

Overview

A group of fastidious, capnophilic (CO2-loving) Gram-negative rods that show gliding motility. Zoonotic species such as C. canimorsus are part of dog and cat oral flora, while other species are human oral commensals.

Classification

  • Gram-negative
  • Rod (fusiform)
  • Capnophilic
  • Gliding motility
  • Facultative anaerobe

Lab & identification clues

  • Slow, CO2-dependent (capnophilic) growth vocabulary
  • Long thin fusiform rods on smear
  • PCR/16S identification concept
  • Oxidase and catalase positive (C. canimorsus)

Associations

  • Dog or cat bite transmission (C. canimorsus)
  • Asplenia and alcohol use as risk-factor vocabulary
  • Sepsis, meningitis, endocarditis study associations
  • Human oral commensal species in neutropenic hosts

Commonly confused with

  • Pasteurella multocida
  • Eikenella corrodens

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