In Corynebacterium diphtheria
• Diphtheria acts by its toxin and invasion is not seen.
• Elekc gel precipitation test is done for determination of pathogenicity of diphtheria.
• Metachromatic granules are seen also called as Babes earnest granules. Bacteriophages (extra-chromosomal) are responsible for toxigenicity by phage conversion.
Deep invasion is not seen
Elek’s test is done for toxigenicity
Metachromatic granules are seen
Toxigenicity is mediated by chromosomal change
Toxigenicity is mediated by chromosomal change