Genomics of food-borne bacterial pathogens

Despite continued efforts to prevent and control food-borne illness it remains a major cause of morbidity and mortality throughout the world. The problem is made worse by the continuous threat from emerging pathogens that can evolve to adapt to the different environments resulting from ongoing changes in farming or food production. The present review discusses the impact of genomics and post-genomic technologies on research in the area of food-borne bacterial pathogens. Genomics research is moving at a fast pace and these are exciting times for microbial research. The genome sequences of approximately ninety bacterial genomes have recently been completed and genome sequences are already available for several food-borne pathogens and closely related species. Comparative genomics is providing new insights into mechanisms of bacterial evolution and has helped in determining virulence factors of pathogens. Genomics has also provided tools such as DNA microarrays that can be used to examine the genetic composition and whole genome expression profiles of bacterial strains by hybridisation of fluorescently labelled DNA. This is helping to identify genes associated with particular phenotypes such as virulence and host preference, and to identify genes in uncharacterised genomes of closely related organisms. Microarrays are also being developed for the detection of food-borne pathogens and investigation of the evolutionary relationship between different species of bacteria. The review concludes with a discussion of the use of functional genomics tools to investigate bacterial responses to environmental stresses and also host-pathogen interactions. These research areas will be valuable in designing future strategies for controlling food-borne pathogens.