[Contamination of flexible fiberoptic bronchoscopes with Mycobacterium chelonae linked to an automated endoscope disinfection machine--on the relationship between the presence of the organism in the intestinal tract and contamination of disinfection machine, and a case of gallbladder and bile duct infection with M. chelonae].

In 1993, thirteen strains (8.7%) of M. chelonae were isolated from bronchoalveolar lavage fluid (BALF) obtained by bronchoscopy of 150 patients in Tachikawa-sogo (T) hospital, where the same automated disinfection machine was commonly used for cleaning, sterilization and disinfection of fiberbronchoscope and fibercolonoscope except 3 bronchoscopes disinfected by gas sterilization. Since January 1994, manual cleaning and sterilization has been applied for bronchoscope, and thereafter no strain of M. chelonae was isolated from BALF of 55 patients in the T hospital. While only one strain (3%) of M. chelonae was isolated from BALF of 33 patients in Ota (O) hospital, but many strains of M. chelonae were isolated from intestinal fluid obtained by fibercolonoscopy of the patients. Manual method of cleaning and disinfection was performed for both bronchoscopes and colonoscopes in the O hospital from the beginning. Based on these results, it was suggested that M. chelonae are commonly present in the colon (intestine) of normal persons. Thus colonoendscope may be often contaminated with the organism and subsequently the automated disinfecting machine may also be contaminated with the organism which is resist and against usual disinfection procedure, and resulted in bronchoscope contamination. If the presence of M. chelonae in intestinal tract is not rare, bile duct may be naturally infected with the organism. A case of cholecystitis and cholangitis caused by M. chelonae, which has not been reported previously, was found in the T hospital.