Insights to the diphtheria toxin encoding prophages amongst clinical isolates of Corynebacterium diphtheriae from India

Dhiviya Prabaa Muthuirulandi Sethuvel, Nithya Subramanian, Agila Kumari Pragasam, Francis Yesurajan Inbanathan, Prashant Gupta, Jaichand Johnson, Naresh Chand Sharma, Nanda Hemvani, Balaji Veeraraghavan, Shalini Anandan, Lucky SangalIndian Journal of Medical Microbiology 2019 37(3):423-425 Diphtheria is a dreadful disease caused by Corynebacterium diphtheriae. Lysogenised bacteriophages carrying toxin gene in C. diphtheriae can make the strain toxigenic. However, such phage disseminates the toxin genes to other strains when it undergoes lytic phase. As little is known about the phage diversity in C. diphtheriae in India, the present study was undertaken to investigate the prophages integrated into the genome of 29 clinical isolates of C. diphtheriae using whole-genome shotgun sequencing. Amongst these isolates, 27 were toxigenic, while 2 were non-toxigenic strains. Of the 27 toxigenic strains, all harbored known phages carrying toxin gene and two other phages with unknown function. However, the two non-toxin strains did not harbour any of the phages in the genome. It is imperative to devise prevention strategies that hinder the dissemination of toxin by prophages, as it may increase the complications of diphtheria post-immunisation.
Source: Indian Journal of Medical Microbiology - Category: Microbiology Authors: Source Type: research