TRUE about corynebacterium diphtheriae are all, EXCEPT:
Corynebacteria are 0.5-1 m in diameter and several micrometers long. Characteristically, they possess irregular swellings at one end that give them the "club-shaped" appearance. Irregularly distributed within the rod (often near the poles) are granules staining deeply with aniline dyes (metachromatic granules) that give the rod a beaded appearance. Diphtheria toxin is absorbed into the mucous membranes and causes destruction of epithelium and a superficial inflammatory response. If disulfide bonds are broken, the molecule can be split into two fragments. Fragment B (MW=38,000), which has no independent activity, is functionally divided into a receptor domain and a translocation domain. Acidification of the translocation domain within a developing endosome leads to creation of a protein channel that facilitates movement of Fragment A into the host cell cytoplasm. Toxin fragment A inactivates EF-2 by catalyzing a reaction that yields free nicotinamide plus an inactive adenosine diphosphate-ribose-EF-2 complex (ADP-ribosylation). It is assumed that the abrupt arrest of protein synthesis is responsible for the necrotizing and neurotoxic effects of diphtheria toxin. The toxigenicity of the corynebacterium diphtheriae is demonstrated by Elek test. Ref: Brooks G.F., Carroll K.C., Butel J.S., Morse S.A., Mietzneron T.A. (2010). Chapter 12. Aerobic Nonspore-Forming Gram-Positive Bacilli: Corynebacterium, Listeria, Erysipelothrix, Actinomycetes, & Related Pathogens. In G.F. Brooks, K.C. Carroll, J.S. Butel, S.A. Morse, T.A. Mietzneron (Eds), Jawetz, Melnick, & Adelberg's Medical Microbiology, 25e.
Has metachromatic granules
Does not invade deeper tissues
Toxigenicity demonstrated by elek's test
Toxin mediated by chromosomal gene