Frequent molecular identification of Campylobacter but not Helicobacter genus in bile and biliary epithelium in...

Bacterial infection of the biliary tree and bile stasis may be causally related to hepatolithiasis, but which bacterial species are involved and their roles in the pathogenesis of hepatolithiasis have not been ascertained. Recently, the Helicobacter genus was detected in human bile and biliary mucosal samples by molecular techniques, and its association with several biliary diseases has been suggested. The Campylobacter genus, which is closely related to the Helicobacter genus, has also recently been identified as causative of human gastrointestinal diseases. This study attempted to elucidate whether Helicobacter and/or Campylobacter bacteria are present in bile samples and biliary mucosal specimens from hepatolithiasis patients and whether they are involved in the pathogenesis of hepatolithiasis. The 16S rRNA gene of the Helicobacter and of the Campylobacter genus was examined by polymerase chain reaction in DNA samples extracted from bile and/or microdissected biliary epithelium from 69 patients with hepatolithiasis and control patients with choledocholithiasis, cholecystolithiasis, and normal gall bladders. The Helicobacter genus was detected in 1 of 8 (13%) biliary epithelial samples in hepatolithiasis and 1 of 10 (10%) bile samples in choledocholithiasis. The Campylobacter genus was detected in 3 of 14 (21%) bile samples and 5 of 8 (63%) epithelial samples in hepatolithiasis, and in 2 of 15 (13%) bile samples and 1 of 8 (13%) epithelial samples in cholecystolithiasis. The detection rate for Campylobacter in biliary epithelium of hepatolithiasis was significantly higher than in the bile or biliary epithelium of control groups (p<0.05). By a phylogenetic analysis based on nucleotide sequences, the Campylobacter genuses detected in hepatolithiasis were clustered with C. rectus or C. showae. The frequent detection of the Campylobacter 16S rRNA gene in bile, and especially in biliary epithelium of hepatolithiasis, suggests a pathogenetic relationship with Campylobacter infection.