Completion of the Campylobacter jejuni NCTC11168 genome sequence offers unrivalled opportunities to understand the molecular basis of virulence for this major pathogen. Among the many novel features revealed by the genome sequence are at least 24 hypervariable sequences mostly found in genes encoding surface structures. Variation in the length of poly G/C tracts in genes containing these hypervariable sequences is frequently found in other mucosal pathogens and is likely to play a key role in enabling C. jejuni to evade the host immune response. Additionally, a novel capsule locus and three sialylation pathways were identified which may be important in the pathogenesis of both uncomplicated diarrhoeal disease and neurological sequelae of infection. The availability of the C. jejuni genome sequence data has coincided with important technological advances in bioinformatics, gene mutagenesis, proteome analysis and DNA microarrays. A C. jejuni DNA microarray holds great promise for transcriptome and comparative genome analysis. Given the range of disease associated with C. jejuni infection, combined with the diverse genotypic and phenotypic properties of clinical and environmental isolates, a Campylobacter DNA microarray will be particularly useful in determining correlates of pathogenicity and in deciphering the epidemiology of the organism. Post genome studies will liberate our understanding of C. jejuni from the piecemeal study of individual genes or operons towards a comprehensive analysis of the entire gene and protein complement. Armed with this wealth of new information, the opportunities to develop improved intervention strategies to reduce C. jejuni in the food chain will be enormous.
