[Evaluation of a micromethod for the bactericidal activity of five disinfectants on 108 hospital strains].

The authors studied 5 disinfectants containing aldehyde and quaternary ammonium against 108 hospital strains. The minimal bactericidal activities (MBC) were determined with a microdilution method and the dilution-neutralization method (AFNOR T 72-150). The microdilution method results were validated using the MBCs of four reference strains tested with the dilution-neutralization method (AFNOR T 72-150). 3 disinfectants proved to be valuable. 1 disinfectant was valuable but with a MBC toward all bacteria only a dilution away from the dilution of use. 1 disinfectant was determined as unsatisfactory as 9.5 p. cent of all strains proved resistant toward it. All disinfectants matched AFNOR standards; but those specifications did not match toward hospital strains. Such an evaluation using a simple and reliable method should be of use.