DETECTION AND PARTIAL SEQUENCE-ANALYSIS OF HELICOBACTER-PYLORI DNA INTHE BILE SAMPLES

The existence of Helicobacter pylori in the biliary tract was investig ated. Seven bile samples were included in this study. Among them, six bile samples were collected by percutaneous transhepatic cholangiodrai nage and the other by needle aspiration during cholecystectomy. Using nested PCR with two sets of primers homologous to the urease A gene, H elicobacter pylori DNA was detected. Three samples, one from a patient with advanced gastric cancer involving the pancreatic head and two fr om patients with pancreatic head tumor, were found to be positive for Helicobacter pylori DNA. On the other hand, three samples from patient s with cholangiocarcinoma and one from a patient with chronic cholecys titis were all negative. To further verify the specificity of our PCR analysis, partial sequences of the PCR products from the three positiv e samples were analyzed by direct sequencing. Several silent mutations and a missense mutation (AAA to AGA; Lys-164 to Arg-164) were identif ied in the urease A gene. We conclude that Helicobacter-pylori DNA can be easily detected in the bile samples. The possibility of asymptomat ic cholangitis caused by this organism requires further investigation.