T4 Bacteriophage May Not Inhibit Transcription of T7 Bacteriophage Genes rpol and gp10a During Co-infection of Escherichia coli

When viruses simultaneously infect the same host cell, this can lead to an altered outcome of infection for the coinfecting pathogens. During the co-infection of Escherichia coli strain C600 with both T4 and T7 bacteriophage, T4 prevents the production of T7 progeny. It is unclear whether T4 inhibits the transcription of T7 genes as a means to achieve this outcome. Thus, the relative expression of earlyand late-phase T7 genes, rpol and gp10a, respectively, as well as late-phase T4 gene gp23 were determined during co-infection of E. coli C600 with T4 and T7 phage. Infected cultures were sampled at 20 and 38 minutes post-infection to identify whether rpol, gp10a, and gp23 transcripts were detectable. Upon optimizing the primer selection, DNase treatment, and PCR conditions, PCR amplification of the the co-infection cDNA yielded both T4 and T7 amplicons. The presence of T7 rpol, T7 gp10a, and T4 gp23 transcripts at both time points from the co-infection suggested that T4 phage likely does not inhibit the transcription of T7 genes as a means of preventing the production of T7 progeny during co-infection of E. coli.