Biliary bacteria: significance and alterations after antibiotic therapy.

Patients undergoing urgent and complex biliary operations were studied to determine (1) whether bactibilia is associated with postoperative complications amd (2) whether antibiotic therapy influences biliary bacteriology. Aerobic and anaerobic cultures were performed on hepatic bile obtained at surgery in 134 patients. Cultures were repeated four to seven days postoperatively in 111 patients who had indwelling biliary tubes. Positive operative bile cultures were associated with an increased incidence of wound infection and postoperative renal dysfunction. Postoperative bile cultures showed a significant increase in the number of patients having bactibilia, and a significant alteration in the types of organisms isolated. Anaerobes were cultured from 15% of operative and 23% of postoperative cultures. Antibiotic therapy did not sterilize bile, but merely altered biliary bacteriology. Furthermore, prolonged aminoglycoside therapy was associated with a high incidence of renal dysfunction, especially in elderly patients.