OBJECTIVE: Numerous investigators have proposed a role for bacteria in biliary lithogenesis. We hypothesized that bacterial DNA is present in gallstones, and that categorical differences exist between gallstone type and the frequency of bacterial sequences. METHODS: Polymerase chain reaction (PCR) was used to amplify bacterial 16S rRNA and uidA (encoding Escherichia coli [E. coli] beta-glucuronidase) genes in different types of gallstones. PCR products were sequenced. RESULTS: Bacterial 16S rRNA and uidA DNA sequences in E. coli were detected in all brown pigment, common bile duct, and mixed cholesterol gallstones (n = 14). In contrast, only one (14%) of seven pure cholesterol gallstones yielded a PCR product. Most (88%) mixed cholesterol gallstones yielded PCR amplification products from their central, as well as their outer, portions. Sequenced products possessed 88-98% identity to 16S rRNA genes of E. coli and Pseudomonas species. CONCLUSIONS: Bacterial DNA sequences are usually present in mixed cholesterol (to 95% cholesterol content), brown pigment, and common bile duct, but rarely in pure cholesterol gallstones. The presence of bacterial beta-glucuronidase is also suggested. The role of bacteria and their products in the formation of mixed cholesterol gallstones, which comprise the majority of cholesterol gallstones, warrants further study.
OBJECTIVE: Numerous investigators have proposed a role for bacteria in biliary lithogenesis. We hypothesized that bacterial DNA is present in gallstones, and that categorical differences exist between gallstone type and the frequency of bacterial sequences. METHODS: Polymerase chain reaction (PCR) was used to amplify bacterial 16S rRNA and uidA (encoding Escherichia coli [E. coli] beta-glucuronidase) genes in different types of gallstones. PCR products were sequenced. RESULTS: Bacterial 16S rRNA and uidA DNA sequences in E. coli were detected in all brown pigment, common bile duct, and mixed cholesterol gallstones (n = 14). In contrast, only one (14%) of seven pure cholesterol gallstones yielded a PCR product. Most (88%) mixed cholesterol gallstones yielded PCR amplification products from their central, as well as their outer, portions. Sequenced products possessed 88-98% identity to 16S rRNA genes of E. coli and Pseudomonas species. CONCLUSIONS: Bacterial DNA sequences are usually present in mixed cholesterol (to 95% cholesterol content), brown pigment, and common bile duct, but rarely in pure cholesterol gallstones. The presence of bacterial beta-glucuronidase is also suggested. The role of bacteria and their products in the formation of mixed cholesterol gallstones, which comprise the majority of cholesterol gallstones, warrants further study.
Authors: Jin-Woo Lee; Don Haeng Lee; Jung Il Lee; Seok Jeong; Kye Sook Kwon; Hyung Gil Kim; Yong Woon Shin; Young Soo Kim; Mi Sook Choi; Si Young Song Journal: Gut Liver Date: 2010-03-25 Impact factor: 4.519
Authors: E Tajeddin; S J Sherafat; M R S Majidi; M Alebouyeh; A H M Alizadeh; M R Zali Journal: Eur J Clin Microbiol Infect Dis Date: 2016-05-18 Impact factor: 3.267