Identification of Helicobacter pylori DNA in human cholesterol gallstones.
BACKGROUND
The gallbladder mucosa secretes hydrogen ions and is covered by mucus. The environmental conditions for bacterial colonization are similar to those in the stomach. Gallbladder stones often contain DNA from enteric bacteria, but no compelling evidence demonstrates that Helicobacter spp. have been present. The aim of this study was to establish bacterial DNA profiles in cholesterol gallstones with special reference to Helicobacter pylori.


METHODS
Cholesterol gallstones from 20 patients were subjected to polymerase chain reaction, bacterial profiling by temporal temperature gradient gel electrophoresis, automated DNA sequencing, and Southern blot analysis using a Helicobacter sp. specific primer. A nested ureI-PCR assay was used to discriminate between gastric and non-gastric H. pylori.


RESULTS
TTGE, partial 16S rDNA sequencing, and hybridization analysis revealed the presence of DNA presumably representing a mixed bacterial flora in cholesterol gallstones, including H. pylori in the gallstone centres in 11 out of 20 patients. In three cases, the urel-PCR assay revealed non-gastric H. pylori.


CONCLUSIONS
These data support the presence of DNA from a mixed bacterial population, including H. pylori in cholesterol gallstones, reflecting either that H. pylori is an indigenous part of a flora in the stone-containing gallbladder or, alternatively, that H. pylori colonization in the biliary tract predisposes to cholesterol gallstone formation.
Monstein
H J
HJ
Molecular Biology Laboratory-LMO, University Hospital, Linköping, Sweden. hanmo@ibk.liu.se
Jonsson
Y
Y
Zdolsek
J
J
Svanvik
J
J
D000328:Adult; D000368:Aged; D002769:Cholelithiasis / Q000235:genetics* / Q000382:microbiology*; D002784:Cholesterol / Q000235:genetics* / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D015342:DNA Probes / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification*; D005260:Female; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009693:Nucleic Acid Hybridization / Q000235:genetics; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D015342:DNA Probes; D004269:DNA, Bacterial; D002784:Cholesterol