[Bacterial elimination and antibiotic concentration in the gall-bladder during biliary tract infections treated with mezlocillin (author's transl)].

A transpapillary indwelling catheter was placed in 15 patients with choledocholithiasis and threatened occlusion by stone. Ten of the 15 patients had marked biliary stasis, four had signs of acute cholangitis. In all patients E. coli was present in the gall-bladder in a concentration of greater than or equal to 10(5)/ml when the catheter was first inserted. The bacteria were sensitive to mezlocillin, at a minimal inhibitor concentration between 1.5 and 16 micrograms/ml. All patients received mezlocillin, 5 g twice daily, in a short-term infusion. Immediately before and regularly thereafter bile samples were taken to measure antibiotic concentration and bacterial counts (by membrane filtration). Mezlocillin was excreted in the bile in very high concentrations in patients without biliary stasis. But while the concentrations were markedly lower in those with stasis, they were still 10 to 100 times the minimum inhibitory concentration of mezlocillin against the appropriate strains. In keeping with the high mezlocillin concentration, bacterial counts fell much more quickly in the patients without stasis than in those with alkaline phosphatase concentration above 250 U/l. These differences were even more marked after two or three days. Bacterial elimination from bile was complete in two of three patients with normal alkaline phosphatase activity, but in only one of five in whom it was elevated.