[Inhibition by "essential" phospholipids of the bactericidal effect of cetylpyridinium chloride on common bacteria. Short communication].

The authors examined the conditions under which the bactericidal action of the disinfectant cetylpyridinium chloride (CPC) is neutralized by a dispersion of "essential" phospholipids (EPL). Both gram-positive and gram-negative strains of bacteria were exposed to various concentrations of the quarternary ammonium over different periods of time. Three cultures were prepared for each contact model to check on the effect of either pre-treatment and after-treatment with phospholipids or of CPC-exposure without the addition of phospholipids. The results obtained demonstrate that EPL are able to "receive" gram-negative bacteria like E. coli, P. aerug. and Morax. glucidol. after exposure to lethal concentrations of CPC for 30 min. While the "phenomenon of restoration" depended on the dose of phospholipids applied, the time of expsure to phospholipids proved irrelevant. The stabilisation of bacterial membranes due to EPL is discussed as a possible explanation of the phenomenon of restoration.