Molecular identification of Helicobacter DNA in human gastric adenocarcinoma tissues using Helicobacter species-specific 16S rRNA PCR amplification and pyrosequencing analysis

Helicobacter pylon (H pylori) is a microaerophilic gram-negative bacterium known to be associated with chronic gastritis, peptic ulcer and gastric adenocarcinoma In the present study, the presence of Helicobacter DNA was investigated using a Helicobacter species-specific 16S rRNA PCR amplification and pyrosequencing analysis in 51 resected gastric adenocarcinomas DNA was extracted from paraffin-embedded tissues of resected gastric adenocarcmomas PCR primers were designed to amplify the 133-bp PCR fragment in highly conserved regions of the 16S rRNA gene The sequence of the PCR products was analyzed using a PSQ 96 system with SQA software The pyrosequencing analysis of 16S rRNA showed that H pylori was present in 47 (92 2%) of the 51 gastric adenocarcinomas In the 4 H pylon-negative cases, Helicobacter cinaedi (2 cases), Helicobacter mustelae (1 case) and Campylobacter hyointestinalis (1 case) were detected Pyrosequencing technology was useful in the identification and differentiation of H pylon from other species by analyzing the gene encoding 16S rRNA Gastric adenocarcinoma tissues contain bacteria, and the majority are H pylon Helicobacter cinaedi, Helicobacter mustelae and Campylobacter hyointestinalis rarely occur The roles of these organisms in the pathogenesis of gastric adenocarcinoma remain unclear