[Bactericial activity of chlorhexidine gluconate against recent clinical isolates of various bacterial species in Japan]

The minimum inhibitory concentration (MIC) and bactericidal activity of chlorhexidine gluconate (CHG) were determined for methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Escherichia coli, Serratia marcescens, Eterobacter cloacae, Pseudomonas aeruginosa and Burkholderia cepacia, isolated from patients in medical institutions all over Japan between 2000 and 2002. The following findings were obtained. 1. The MICs of CHG against MSSA, MRSA, E. coli and B. cepacia were 0.002% or less, and those against S. marcescens, E. cloacae and P. aeruginosa were 0.008% or less. 2. Rapid and strong bactericidal effects of CHG were observed against all clinical isolates of E. coli, E. cloacae and P. aeruginosa tested even at relatively low concentrations (0.02 to 0.05%). 3. Relatively high concentration or prolonged treatment time was required to achieve sufficient bactericidal effect of CHG against some isolates of S. aureus, S. marcescens and B. cepacia. These results suggest that CHG is useful antiseptic agent or disinfectant for recent clinical isolates of various bacterial pathogens. In addition, the selection of treatment concentration and treatment time for each organism and purpose was important to obtain sufficient bactericidal effect.