Polymorphism ofcagA andvacAgenes inHelicobacter pyloriisolated from gastroduodenal diseas patients in Central Vietnam

H. pyloriplays a significant role in the pathogenesis of upper alimentary tract diseases. Vietnam is a developing country with high prevalence ofH. pyloriinfection and an intermediate risk of gastric cancer. The aim of this thesis was to determine the antibiogram and the molecular basis of the resistance pattern; to investigatecagAandvacAgenotypes, and to determine a clinical relevance ofcagAandvacApolymorphisms ofH. pyloristrains isolated from dyspeptic patients in Central Vietnam.We examined dyspeptic patients who were referred to Hue University Hospital between July 2012 and January 2014. A total of 92 strains antibiogram was performed by E-test and 96 extracted DNA samples from 96 strains were available for analysis. Point mutations related to clarithromycin and levofloxacin on 23SrRNAandgyrAgenes were detected by sequencing.vacAandcagAgenotyping were carried out using PCR and sequencing, then their clinical relevance was further analyzed.We highlight a very high resistance rate in Central Vietnam with 56.5% of multiple resistance and higher prevalence of secondary resistanceversusprimary resistance. Data on determinants of resistance to clarithomycin and levofloxacin are new information in Vietnam.cagApositivestatus, East AsiancagAtype andvacAs1i1m1 type are the most predominant in gastric ulcer and gastric cancer. The prevalence ofcagAnegative status and WesterncagAtype is higher than that reported in previous studies in Vietnam.