Several Helicobacter species are known to colonize the biliary tract in animals and have been identified in the gallbladder bile of a high proportion of Chilean patients with
gallbladder cancer. In this study, we tried to examine the presence of Helicobacter species in the bile to know their participation in the development of extrahepatic biliary diseases.
DNA was extracted from 57 bile samples from 30 patients with benign biliary diseases (
cholecystolithiasis and choledochocystolithiasis), 6 malignant biliary
diseases (gallbladder cancer and common bile duct
cancer), and 21 nonbiliary diseases. The presence of Helicobacter genus-, H. pylori-, H. hepaticus-, and H. bilis-specific
16S rRNA genes, the H. pylori
urease A gene, and the H. pylori 26K
protein gene in the bile was determined by PCR and sequencing analysis. Helicobacter genus
DNA (shorter amplicons, 400 bp) was statistically frequently detected in biles from 53% (16/30) and 86% (5/6) of benign and malignant biliary diseases, compared with 9% (2/21) of nonbiliary diseases, but longer amplicons (1200 bp) were not detectable in any samples. The H. pylori
urease A gene (nested amplicon) was also frequently found in bile, whether benign, malignant, or control, though neither H. pylori
16S rRNA nor the 26K
protein gene was detectable in any bile samples. H. bilis-16S rRNA genes were detectable in only two cases. H. hepaticus was not detectable in any samples.
DNA fragments of Helicobacter species other than H. pylori, H. hepaticus, and H. bilis are commonly detectable in the bile of patients with extrahepatic biliary diseases, whether benign or malignant, implying that the Helicobacter genus may be directly or indirectly involved in the pathogenesis of these diseases.