title: Anaerobic bacteria and intrahepatic stones: detections of Clostridium sp. and Bacteroides fragilis.
abstract: OBJECTIVE
  To detect anaerobic bacteria Clostridium sp. and Bacteroides fragilis in intrahepatic stones by molecular genetic method.
  
  
  METHODS
  DNA was extracted from 59 stone samples and subjected to polymerase chain reaction (PCR) amplification targeting the 16S rRNA gene of Clostridium sp. and the glutamine synthetase gene of Bacteroides fragilis. Single-strand conformational polymorphism (SSCP) analysis was performed to identify the Clostridium sp.
  
  
  RESULTS
  16S rRNA gene sequences for Clostridium sp. were identified in 49 stones (83%, 49/59). The two most common groups were detected in 19 (41%) and 17 (37%) of the 46 samples using SSPC analysis, and 25/59 (42%) stones were tested positive for Bacteroides fragilis.
  
  
  CONCLUSIONS
  Anaerobes such as Clostridium sp. and Bacteroides fragilis present in intrahepatic stones and may play a role in stone formation. PCR is a useful technique to detect fastidious pathogens, which are difficult to culture. SSCP of PCR products is a rapid method in differentiating bacterial species.
authors.affiliation: Division of Gastroenterology, University of California, Davis Medical Center, Sacramento, CA 95817, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: K
authors.initials: K
authors.lastname: Lam
authors.forename: Y J
authors.initials: YJ
authors.lastname: Tang
authors.forename: P H
authors.initials: PH
authors.lastname: Gumerlock
authors.forename: D K
authors.initials: DK
authors.lastname: Lee
authors.forename: M H
authors.initials: MH
authors.lastname: Kim
authors.forename: S P
authors.initials: SP
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Silva
authors.forename: J W
authors.initials: JW
authors.lastname: Leung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001421:Bacteria, Anaerobic / Q000235:genetics* / Q000302:isolation & purification; D001441:Bacteroides fragilis / Q000235:genetics; D001653:Bile Ducts, Intrahepatic / Q000382:microbiology* / Q000473:pathology; D002769:Cholelithiasis / Q000382:microbiology* / Q000473:pathology; D003013:Clostridium / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D005974:Glutamate-Ammonia Ligase / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D005974:Glutamate-Ammonia Ligase