Role of bacterial biofilms in the chemotherapy of cholangitis with brown pigment stones.

The purpose of the present study was to clarify the role of biofilms in the chemotherapy of cholangitis. In 1 case of recurrent cholangitis with intrahepatic stones, the patient underwent right hepatectomy after chemotherapy was performed for 42 weeks. In the other case, chemotherapy including ciprofloxacin was performed during an attack of recurrent cholangitis. Repeated culture of bile specimens yielded negative results, whereas culture of the choledochal stone yielded Pseudomonas aeruginosa. We observed an acute transient IgM response to a component of the biofilm of P. aeruginosa (alginate) in this case. In both cases, electron microscopy revealed viable bacteria covered with biofilm in the component of brown pigment stones. It was concluded that biofilm is a factor of drug resistance.