The effect of stress on genetic recombination and pathogenicity of Shiga toxin-encoding bacteriophages

Shiga toxin-producing Escherichia coli (STEC) is recognised as an emerging human pathogen, which is transmitted from its animal reservoirs causing severe and potentially fatal gastrointestinal diseases in humans. Genes encoding the major virulence factors , the shiga toxins, are carried by a heterogenous population of lambdoid bacteriophages (stx-phages). The mosaic structure of the stx-phages indicate frequent recombination of genes from a common bacteriophage gene pool. Studies of the stx-phage pool andg enetic recombination within this pool are required to determine the role played by these phages in STEC epidemiology and virulence. The results of the present study will contribute to elucidate this role. The focus of the study is on how environmental str ess may have an impact on bacteriophage recombination, and how such recombination events may effect the pathogenicy and survival of the host bacterium. Experiments willbe done in food and animal model systems. Microchip technology