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
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.