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