True about Corynebacterium diphtheriae are all except:

Ans. (b) Toxin production is responsible for local reaction "Mechanical complications of diphtheria are due to the membrane while the systemic effects are due to the toxin." Toxin acts mainly systemically though there are paial local effects. It has affinity for myocardium, adrenals and nerve endings. Toxin acts by inactivating EF-2 thus inhibiting protein synthesis. Toxin production is influenced by iron concentration in the medium. Toxin production is optimal at 0.14 p.g/ ml and is suppressed at 0.5 .tg/ml. Toxigenicity of diphtheria bacillus depends on symbiotic bacteriophages, so it shows lysogenic or phage conversion i.e. nontoxigenic strain toxigenic strain by infecting with beta phage.