Comparative genomics ofHelicobacter pyloriisolates recovered from ulcer disease patients in England

Background. Genomic diversity ofH. pylorifrom many different human populations is largely unknown. We compared genomes of 65H. pyloristrains from Nottingham, England. Molecular analysis was carried out to identify rearrangements within and outside thecag-pathogenicity-island (cagPAI) and DNA sequence divergence in candidate genes. Phylogenetic analysis was carried out based on various high-resolution genotyping techniques.Results. Analyses of virulence genes (cagT,cagE,cagA,vacA,iceA,oipA andbabB) revealed thatH. pyloristrains from England are genetically distinct from strains obtained from other countries. The toxigenicvacA s1m1 genotype was found to be less common and the plasticity region cluster was found to be disrupted in all the isolates. English isolates showed a predominance oficeA1 alleles and a functional proinflammatoryoipA gene. The EnglishH. pylorigene pool revealed several Asian/oriental features. This included the predominance ofcagA –glr(cagA right junction) motif types III and II (up to 42%), presence ofvacA m1c alleles and phylogenetic affinity towards East Asian / Amerindian gene pools based on fluorescent amplified fragment length polymorphism (FAFLP) analysis andglmM sequence analysis.Conclusion. Overall, our results demonstrated genetic affinities ofH. pyloriin England with both European and the Asian gene pools and some distinctive genetic features of virulence genes that may have evolved in this important European population.