Lysogenic infection of a Shiga toxin 2-converting bacteriophage changes host gene expression, enhances host acid resistance and motility

Shiga toxin 2 (Stx2)-converting bacteriophages ca n infect and lysogenized other bacteria in vivo and in vitro, and thus contribute to the genotypic heterogeneity of infected host. However, the global transcription patterns accompanying the lysogenic infection of Escherichia coli coli host have not been clearly resolved. In this study, we compared the gene expression profiles of Stx2 phage I broken vertical bar Min27(Delta stx::cat) converted and na < ve E. coli MG1655 hosts using microarray analyses. It was identified that conversion by I broken vertical bar Min27(Delta stx::cat) had a direct effect on the global expression of bacterial host genes as 166 genes were found to be differentially expressed (104 up-regulated and 62 down-regulated). These genes were predominantly responsible for bacterial central metabolism, transport and transcription. It was shown that in addition to the down-regulation of genes involved in synthesis of Thi an d protein transporters, expression of genes associated with bacterial energy production (e.g., fadABDEHIJL, aceK and acnA) were also suppressed. Conversely, a significantly larger number of genes were up-regulated, including transport genes, flagellar synthesis genes (fliDESTZ) and acid resistant genes (e.g., gadEW, hdeABD and adiY). Our study also discovered conversion of I broken vertical bar Min27(Delta stx::cat) could change host physiological character. The converted cells had increased acid tolerance at low pH and promoted swimming motility on semisolid agar surface compared to the uninfected bacterial host.