Susceptibility of Indigenous Bacteria in Clinical Divisions to Habitual Disinfectants

Susceptibility of 29 bacterial strains including Pseudomonas aeruginosa, Ps. cepacia and Serratia marcescens, which were isolated recently from the flange of sink at various clinical divisions in Yamagata University Hospital, to 4 disinfectants, Chlorhexidine gluconate (CHG), Benzalkonium chloride (BAC), Saponated cresol (SAC) and Povidone iodine (PVP-I), was examined at the concentration recommended for disinfection of hands. 1. Although all of the isolates tested were sensitive to SAC and PVP-I, susceptibility to CHG and BAC varied from species to species and also from strain to strain. 2. Eighteen strains of Ps. aeruginosa tested were sensitive to CHG and BAC. 3. Three strains of Ps. cepacia tested were resistant to CHG. 4. Five of eight strains of Se. marcescens tested were resistant to CHG and BAC. 5. Two strains of Se. marcescens isolated from hands of doctors had the same biochemical properties and the susceptibility to disinfectants and antibiotics as those of the isolates from clinical divisions. These results indicate that the resistant strains of Ps. cepacia and Se. marcescens against CHG and BAC at the concentration recommended for disinfection of hands are present in hospital, and that these strains may cause nosocomial infection through medical treatments.