The microbiology of direct bile sampling at the time of endoscopic retrograde cholangiopancreatography

Summary Using a technique of sampling bile directly from the common bile duct at the time of endoscopic retrograde cholangiopancreatography (ERCP), the range of bacteria in the bile was studied quantitatively in patients with and without biliary disease. Bile specimens from io normal subjects were not infected. Twenty-one out of 22 patients (95 per cent) with stones in the common bile duct, and four out of seven patients with gall bladder stones had infected bile. A pure growth of a single infecting organism was found in only five of the 25 patients with infected bile. There was a high incidence of resistance to ampicillin amongst the coliform organisms isolated. The bile from patients following sphincterotomy was uniformly infected by mixed growths of bacteria. Bacteriological investigation of bile obtained by ERCP permits the choice of an appropriate antibiotic for use following the procedure, or to cover a subsequent operation, in a patient with gall stones and biliary infection.