Type your tag names separated by a space and hit enter
Official website of the Johns Hopkins Antibiotic (ABX), HIV, Diabetes, and Psychiatry Guides, powered by Unbound Medicine. Johns Hopkins Guide App for iOS, iPhone, iPad, and Android included. Explore these free sample topics:
-- The first section of this topic is shown below --
- Pleomorphic Gram-positive bacillus that is club-shaped, appears like Chinese characters on Gram stain [Fig].
- Facultative anaerobe.
- Humans are only known hosts.
- Diphtheria caused only by exotoxin-producing strains of C. diphtheriae.
- Three Corynebacterium strains may produce diphtheria toxin:
- C. diphtheriae (epidemic diphtheria w/ person-person spread)
- C. ulcerans
- C. pseudotuberculosis
- Both C. ulcerans and C. pseudotuberculosis are less common and associated with farm/dairy contacts.
- Virulent C. diphtheria strains carry a bacteriophage with the diphtheria toxin gene. Without this bacteriophage, the microbe is unable to cause serious disease.
- Culture best performed on tellurite-selective media, e.g., Tinsdale agar.
- Confirmation of toxin production by demonstration of an immunoprecipitin band done at CDC.