title: Identification of Helicobacter pylori in Gallstone, Bile, and Other Hepatobiliary Tissues of Patients with Cholecystitis.
abstract: OBJECTIVE
  Bacterial infection is accepted as a precipitating factor in cholesterol gallstone formation, and recent studies have revealed the presence of Helicobacter species in the hepatobiliary system. We utilized the polymerase chain reaction (PCR) to establish the presence of bacterial DNA, including from Helicobacter species, in gallstones, bile juice, and gallbladder mucosa from patients with gallstones.
  
  
  METHODS
  At cholecystectomy, 58 gallstones, 48 bile samples, and 46 gallbladder mucosa specimens were obtained and subjected to nested PCR using specific 16S rRNA primers of H. pylori and other bacteria. Bacterial species were identified by DNA sequencing analysis. Bacterial 16S rRNA was detected in 25 out of 36 mixed-cholesterol gallstones, 1 out of 10 pure-cholesterol gallstones, and 9 out of 12 pigmented stones. Furthermore, 16S rDNA sequencing identified Escherichia coli, Pseudomonas, Citrobacter, Klebsiella, and Helicobacter species.
  
  
  RESULTS
  Helicobacter DNA was detected in 4 out of 58 gallstones, 6 out of 48 bile samples, and 5 out of 46 gallbladder specimens. Direct sequencing of Helicobacter amplicons confirmed strains of H. pylori in all four gallstones, five out of six bile samples, and three out of five gallbladder specimens. Almost all mixed-cholesterol gallstones appear to harbor bacterial DNA, predominantly E. coli.
  
  
  CONCLUSIONS
  H. pylori was also found in the biliary system, suggesting that these bacteria are of etiological importance in gallstone formation.
authors.affiliation: Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Lee
authors.forename: Don Haeng
authors.initials: DH
authors.lastname: Lee
authors.forename: Jung Il
authors.initials: JI
authors.lastname: Lee
authors.forename: Seok
authors.initials: S
authors.lastname: Jeong
authors.forename: Kye Sook
authors.initials: KS
authors.lastname: Kwon
authors.forename: Hyung Gil
authors.initials: HG
authors.lastname: Kim
authors.forename: Yong Woon
authors.initials: YW
authors.lastname: Shin
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Kim
authors.forename: Mi Sook
authors.initials: MS
authors.lastname: Choi
authors.forename: Si Young
authors.initials: SY
authors.lastname: Song