Bacterium
Corynebacterium diphtheriae
Club-shaped Gram-positive rod with toxin clue
kor-eye-nee-bak-TEER-ee-um dif-THEER-ee-eye
High-yield clue
Club-shaped rods in palisades + diphtheria toxin blocks EF-2 vocabulary.
Overview
A club-shaped Gram-positive rod used for palisade morphology, exotoxin mechanism vocabulary, and toxoid vaccine concepts.
Classification
- Gram-positive
- Pleomorphic rod
- Toxin-mediated disease concept
Lab & identification clues
- Palisade or Chinese-letter arrangement
- Metachromatic granule vocabulary
- Toxin testing concept
Associations
- Pseudomembrane vocabulary
- Myocarditis/neuropathy toxin associations
- Toxoid vaccine concept
Commonly confused with
- Listeria monocytogenes
- Bacillus anthracis
Frequently asked questions
What is Corynebacterium diphtheriae?
A club-shaped Gram-positive rod used for palisade morphology, exotoxin mechanism vocabulary, and toxoid vaccine concepts.
What is the Gram stain of Corynebacterium diphtheriae?
Corynebacterium diphtheriae is Gram positive.
What are the lab clues for Corynebacterium diphtheriae?
Lab clues for Corynebacterium diphtheriae include Palisade or Chinese-letter arrangement, Metachromatic granule vocabulary, and Toxin testing concept.
What is Corynebacterium diphtheriae commonly confused with?
Corynebacterium diphtheriae is commonly confused with Listeria monocytogenes and Bacillus anthracis.
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.