Resistant pathogens in biliary obstruction: importance of cultures to guide antibiotic therapy.

BACKGROUND Cholangitis, infection of the bile ducts, is a serious condition that necessitates prompt and efficacious treatment for a good clinical outcome. A single center retrospective study of cholangitis was conducted to better define the spectrum of responsible pathogens and their antibiotic sensitivities. METHODS We studied all patients at our hospital who had cholangitis from January 1998 to June 2004. Patients were identified by ICD-9 codes and the cause of the cholangitis, the treatment and culture data were noted by review of the medical record. RESULTS Thirty patients presented with cholangitis as noted by the clinical symptoms of jaundice, fever and abdominal pain. The cause of the biliary obstruction was gallstones in 18 patients, benign biliary strictures in 5 and malignant obstruction in 7. All the patients with malignant obstruction with cholangitis had stents; there were no cases of cholangitis in malignant obstruction unless prior instrumentation had been performed. The most common isolates were Enterococcus>E. coli>Enterobacter>Klebsiella. Sixty-four percent of blood cultures and all but one of the bile cultures grew organisms. Seventy-two percent of patients had positive blood cultures with at least one resistant organism present and 36% had organisms resistant to multiple antibiotics. Fifty percent of patients with benign biliary disease and positive blood cultures had multiple organisms growing in their blood. Three-quarters of the isolates were resistant to one or more antibiotics and one-quarter of isolates were resistant to three or more antibiotics. Resistant organisms were found regardless of the cause of the biliary obstruction. DISCUSSION For all causes of cholangitis, there is a high incidence of positive blood cultures and a high rate of antibiotic resistance. For optimal treatment, blood and/or bile cultures should be routinely performed to optimize antibiotic therapy.