Microflora of the biliary tree and liver--clinical correlates

Microbiologic aspects of hepatobiliary tracts are reviewed. The gallbladder, the common duct and the liver are discussed separately. Special attention is paid to bacteriologic sampling technique. Factors associated with bactibilia are surveyed. The relation between biliary bacteria and stone formation is evaluated. The etiology of acute calculous and acalculous cholecystitis, cholangitis and pyogenic liver abscess is discussed from a microbiological point of view. The importance of new imaging techniques, such as ultrasound, radionuclide scanning and computerized tomography, in the diagnosis and treatment of biliary obstruction or hepatic abscess is recognized. The type of bacteria and their incidence in bile was strongly associated with the underlying condition and various host factors. The flora in acute cholecystitis closely resembled that of the small intestine, while cholangitis and hepatic abscess specimens grew species often found in the colon. In addition, 'microaerophilic streptococci' were especially abundant in hepatic abscess. Nonetheless, coliforms predominated at all loci. Depending on selection criteria of the study population, bacteria of biliary origin played varying roles in the development of postoperative sepsis. Principles of perioperative antibiotic prophylaxis and treatment of manifest infection are outlined.