In Corynebacterium diphtheria: (A) Deep invasion is not seen, (B) Elek’s test is done for toxigenicity, (C) Metachromatic granules are seen, (D) Toxigenicity is mediated by chromosomal change
Answer is D. • 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.