Biliary sepsis: an ascending infection.

ABSTRACT

AIM: To study the bacteriology of normal and obstructed biliary tree and determine the mode of biliary infection. METHODS: Fifty seven patients undergoing elective biliary surgery for calculous biliary disease cholecystitis 45, obstructive jaundice 12) were studied. Bile samples collected separately from gall bladder, common bile duct and duodenum at the time of surgery were processed for aerobic and anaerobic cultures and antibiotic assays. To locate endogenous foci of infection, urine, nasal swab and throat swab cultures were done. Isolates from/biliary tract were compared with those from other sites. RESULTS: Thirty eight patients (66.7%) had bactobilia. The prevalence was higher in patients with obstructive jaundice (10/12, 83.3%) than (p = 0.5) in those with non-obstructed biliary tree. Single bacterial infection (31 cases, 81 %) was more common than mixed infection (7 cases, 19%). Colonization of more than one segment of the biliary tree was seen in 30 patients (79%). E coli was the most frequently isolated organism. In 24 cases (63.2%), strains of organisms from the common bile duct and gall bladder were similar to those from the duodenum, and in only 10 cases (23.2%) were similar to those found in the nose, throat and urine. The antibiotic concentrations in the common bile duct after single doses of preoperative antibiotic (gentamicin and cephazolin) were lower in the obstructed biliary tree (1.5 +/- 0.4 milligrams/mL and 2.8 milligrams/mL respectively) than in the non-obstructed system (3.9 +/- 1.7 milligrams and 12.6 milligrams/mL/mL respectively) (p = 0.5 for both antibiotics). CONCLUSION: Ascending infection forms the mode of biliary sepsis in a majority of cases. Prophylactic antibiotics give low levels in the bile in an obstructed biliary tree.