Microbial Phage Conversion

Phage Conversion

Freeman (1951) critically took cognizance of the fact that in a specific condition ‘certain non-toxic strains’ of the bacterial sp. Corynebacterium diphtheriae (causing the dreadful disease ‘diphthe-ria’ amongst children), are duly subjected to adequate treatment with a ‘phage suspension’ that has been carefully obtained from a highly ‘virulent toxigenic strain’ of the same species, then a certain proportion of survivors acquired the substantial capability of synthesizing the toxin and maintaining the adequate desired ‘immunity’ particularly to the ‘lytic infection’ by the respective phage.

However, further follow up investigational studies have duly revealed that this specific sort of typical conversion from a nontoxigenic to a toxigenic strain was primarily caused on account of the adequate establishment of the phenomenon of ‘lysogeny’**, and subsequently the inherent ability to cause production of the toxin was lost virtually along with the complete loss of the phage.

Conclusively, based upon the marked and pronounced presence of the correlation between ‘lysonization’ and ‘toxin generation’ the said phenomenon was approximately termed as — ‘lysogenic conversion’. Nevertheless, further elaborative studies distinctly helped to discover the fact that particu-lar virulent mutants of the converting phages may also reasonably initiate the toxin synthesis, which is known as ‘phage conversion’.

Example : Phage conversion seems to be extraordinarily abundant and most frequent amongst organisms.

The glaring production of the somatic antigens in the Salmonella sp. by the help of various recognized strains of the ‘Group E’ has been duly observed to be intimately related to the presence of some very specific bacteriophage genomes.