Evaluation of Biliary Bacterial Resistance in Patients with Frequent Biliary Instrumentation, One Size Does Not Fit All

Bacteremia due to cholangitis can occur as a complication of biliary instrumentation. Biliary sepsis can result from frequent endoscopic retrograde cholangiopancreatography (ERCP). We hypothesized that routine use of antibiotics in patients who require frequent ERCPs leads to cholangitis resistant to empiric antibiotics used to treat biliary sepsis. We retrospectively reviewed patients with frequent biliary instrumentation and blood stream infection due to cholangitis. Conventional empiric antibiotics were defined as broad-spectrum antibacterial agents predominantly used for community-acquired infections and surgical prophylaxis. Broad-spectrum antibacterial agents used for hospital-onset/multidrug-resistant infections were defined as broad-spectrum MDR antibiotics. Seventy-eight patients had bacteremia secondary to cholangitis from biliary obstruction. Over 50% of bacteria were not sensitive to conventional empiric antibiotics for biliary sepsis. Thirty-seven patients did not receive post-procedural antibiotics and forty-one patients did. Of the ones who did, 58% later had a bloodstream infection with bacteria resistant to the antibiotic used for prophylaxis, and 26 patients (63%) required a broad-spectrum MDR antibiotic for treatment. The number of ERCPs was not associated with resistance to prophylactic antibiotics (p 0.7103) or needing broad-spectrum MDR antibiotics for treatment of cholangitis-associated bacteremia (p 0.1868). Routine use of antibiotic prophylaxis after ERCP was associated with trend toward need for broad-spectrum MDR antibiotics for cholangitis-associated bacteremia, Chi-square 3.7, 0 0.0540. Bacterial resistance to conventional empiric antibiotics is an emerging problem. Blood cultures are needed to guide therapy.