Anaerobic bacteria and intrahepatic stones: detections of Clostridium sp and Bacteroides fragilis

Objective To detect anaerobic bacteria Clostridium sp. and Bacteroides frag ilis 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 Clostrid ium sp. and the glutamine synthetase gene of Bacteroides fragilis. Single-s trand conformational polymorphism (SSCP) analysis was performed to identify the Clostridium sp. Results 16S rRNA gene sequences for Clostridium sp, were identified in 49 s tones (83%, 49/59). The two most common groups were detected in 19 (41%) an d 17 (37%) of the 46 samples using SSPC analysis, and 25/59 (42%) stones we re tested positive for Bacteroides fragilis. Conclusions Anaerobes such as Clostridium sp. and Bacteroides fragilis pres ent in intrahepatic stones and may play a role in stone formation. PCR is a useful technique to detect fastidious pathogens, which are difficult to cu lture. SSCP of PCR products is a rapid method in differentiating bacterial species.