Detection and partial sequence analysis ofHelicobacter pylori DNA in the bile samples

The existence ofhelicobacter pylori in the biliary tract was investigated. Seven bile samples were included in this study. Among them, six bile samples were collected by percutaneous transhepatic cholangiodrainage and the other by needle aspiration during cholecystectomy. Using nested PCR with two sets of primers homologous to the urease A gene,Helicobacter pylori DNA was detected. Three samples, one from a patient with advanced gastric cancer involving the pancreatic head and two from patients with pancreatic head tumor, were found to be positive forHelicobacter pylori DNA. On the other hand, three samples from patients with cholangiocarcinoma and one from a patient with chronic cholecystitis were all negative. To further verify the specificity of our PCR analysis, partial sequences of the PCR products from the three positive samples were analyzed by direct sequencing. Several silent mutations and a missense mutation (AAA to AGA; Lys-164 to Arg-164) were identified in the urease A gene. We conclude thatHelicobacter pylori DNA can be easily detected in the bile samples. The possibility of asymptomatic cholangitis caused by this organism requires further investigation.This study was supported in part by grants from Chang Gung Medical Center (CMRPs) and also by a grant from the Prosperous Foundation, Taipei, Taiwan.