Phattharaphon Wongphutorn1,4, Kittipan Samerpitak1, Narong Khuntikeo 2,4, Kookwan Sawadpanich3, Wongwarut Boonyanugomol5 and Chariya Chomvarin1,4*
1Department of Microbiology, 2Department of Surgery, 3Department of Medicine, Faculty of Medicine; Khon Kaen University, Khon Kaen, Thailand.
4Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University,
5Mahidol University, AmnatChareon Campus, AmnatChareon, Thailand.
Helicobacter pylori is an important causative agent of gastrointestinal and hepatobiliary diseases. The aim of this study was to investigate phylogenetic relationships among H. pylori strains from the oral cavities of healthy individuals, gastric biopsies from gastroduodenal (GI) patients and bile samples from hepatobiliary (HB) patients in the northeast of Thailand. The DNA sequences of a portion of the vacuolating cytotoxin A gene (vacA) were investigated. Phylogenetic trees were constructed using the neighbor-joining and maximum-likelihood methods. The vacA sequences of H. pylori fell into four main groups on the trees. Strains from healthy persons fell into two widely separated but well-supported groups, while most H. pylori vacA sequences from HB patients were distributed in another two groups. In contrast, the H. pylori strains from GI patients were scattered across the tree, without a clear geographical pattern. In conclusion, the sequence of vacA may be useful to classify the genetic relationship of H. pylori derived from different sources.
Keyword: H. pylori, vacuolating cytotoxin A gene, gastrointestinal diseases, hepatobiliary diseases and healthy persons.