Isolation and characterization of bacteriophages from India, with lytic activity againstMycobacterium tuberculosis

Abstract

Bacteriophages are being considered as a promising natural resource for the development of alternative strategies against mycobacterial diseases, especially in the context of the wide-spread occurrence of drug resistance among the clinical isolates of Mycobacterium tuberculosis. However, there is not much information documented on mycobacteriophages from India. Here, we report the isolation of 17 mycobacteriophages using Mycobacterium smegmatis as the bacterial host, where 9 phages also lyse M. tuberculosis H37Rv. We present detailed analysis of one of these mycobacteriophages - PDRPv. Transmission electron microscopy and polymerase chain reaction analysis (of a conserved region within the TMP gene) show PDRPv to belong to the Siphoviridae family and B1 subcluster, respectively. The genome (69 110 bp) of PDRPv is circularly permuted double-stranded DNA with ∼66% GC content and has 106 open reading frames (ORFs). On the basis of sequence similarity and conserved domains, we have assigned function to 28 ORFs and have broadly categorized them into 6 groups that are related to replication and genome maintenance, DNA packaging, virion release, structural proteins, lysogeny-related genes and endolysins. The present study reports the occurrence of novel antimycobacterial phages in India and highlights their potential to contribute to our understanding of these phages and their gene products as potential antimicrobial agents.

<p>Phage therapy as a renewed therapeutic approach to mycobacterial infections: a comprehensive review</p>

“…In recent years, several novel alternative strategies including therapeutic enzymes, pigments, phytochemicals, antimicrobial polymers, antimicrobial peptides, and silver nanoparticles have led researchers to consider the treatment of infections in the presence of MDR and XDR pathogens 1,10,11. However, since drug-resistant bacteria have become increasingly problematic and challenging, phage therapy is considered to be an important candidate for alternative therapy 12. Bacteriophages are viruses that are isolated from several ecological specimens including sewage, soil, and water 13–15.…”

“…It is estimated that there are more than 4200 bacteriophages that exactly infect Mycobacterium spp; it is expected that 1025 phage launches a new infection cycle in every second of the day 18. The application of bacteriophage as a candidate for alternative therapy in non-mycobacterial infection was discovered in the early 20 th century, showing that bacteriophage has a high capacity to efficiently eradicate pathogenic bacteria 12,19,20…”

“…Mycobacteriophages (PDRPv) belong to Siphoviridae family and B1 sub-cluster. The length of the mycobacteriophage PDRPv genome is approximately 69,110 bp with a G+C content of ~66%, containing 106 open reading frames (ORFs) 12,79. The results of another study revealed that phage PDRPv had a lytic activity against Mtb.…”

“…The results of another study revealed that phage PDRPv had a lytic activity against Mtb. However, the exact anti-tuberculosis mechanism of this phage was not determined 12…”

Antimycobacterial potential of Mycobacteriophage under disease-mimicking conditions

“…Five phages (D29, TM4, Che7, PDRPv (Bajpai et al, 2018) and PDRPxv (Sinha et al, 2020)) used in this study were amplified on M. smegmatis . Similarly, three phages (D29, TM4 and DS6A) were amplified on M. tuberculosis .…”