Primary bile duct stones and bacterial activity.

The results of this study suggest that infection with beta-glucuronidase active bacteria is the initial event in the nucleation of primary bile duct stones (PBDS). PBDS from five patients were morphologically fragile and "earthy" with alternating light and dark brown pigment layers with no evidence of a distinct central nucleus that may have been reminiscent of a different structure. Chemically, calcium bilirubinate and calcium palmitate were prominent throughout their structure. All bile duct biles had a positive culture and were always associated with at least one bacterial species which was beta-glucuronidase active. Moreover, fragments of PBDS nuclear areas had positive cultures that were comparable with those present in their individual bile duct bile. Microscopic examination of bile showed abundant precipitation of calcium bilirubinate granules in all samples. Thus, bile duct bile infection with beta-glucuronidase active bacteria (e.g. E. coli, C. perfringens) appears to be a key factor in PBDS pathogenesis, having a precursor role, rather than being a consequence. Bile stasis is likely to be a co-factor which must have a supportive role in subsequent stone growth.