Abstract

Bacteriophages are viruses that specifically infect bacteria and utilize host machinery to replicate and proliferate. Temperate bacteriophages inject their genetic material into the host cell, where it is integrated into the host genome, forming a lysogen. Once a lysogen is formed, bacteriophages use repressors to prevent lysis and to block replication of other infecting bacteriophages from the same cluster. Xeno is a temperate bacteriophage that infects Mycobacterium smegmatis and is part of Cluster N group of mycobacteriophages. The Xeno lysogen has shown immunity to bacteriophages from other clusters suggesting that alternate modes of repression may be involved. As part of a national study, we have tested the Xeno lysogen, in immunity assays. Bacteriophage lysates collected in the Phage Hunter courses at Carthage College from 2011 to 2016 were used in the immunity assays by diluting and spotting each phage lysate onto bacterial lawns of the Xeno lysogen and the control plates with Mycobacterium smegmatis to determine efficiency of plating. Phages that had over a 10000-fold difference in efficiency of plating have been further tested to verify the immunity status.