The striking similarities between the innate defenses of vertebrates and invertebrates as well as the amenability of Caenorhabditis elegans for genetic analysis have made this free-living ground nematode a popular model system in the study of bacterial pathogenesis. Although genetic studies have brought new insights, showing the inducibility and pathogen-specificity of the immune response, there is still much to be discovered about the exact mechanisms underlying resistance to infection. In this study a different angle was adopted to study host-pathogen interactions in C. elegans. Given the dynamic nature of an immune response, the proteome of C. elegans was investigated at four different time-points (24, 48, 72, 96 h) after infection with S. typhi, S. typhi Ty21a, C. sakazakii and E. coli OP50 using SDS PAGE as a preliminary step to detect variation in the whole protein content.