SUBINHIBITORY CONCENTRATIONS OF ORGANIC AMMONIUM-SALTS - THE EFFECT ON BIOLOGICAL PROPERTIES OF SALMONELLA-TYPHIMURIUM

The effect of subinhibitory concentrations (subMICs) of new organic am monium salts of four homologous series of alkylammonium bromides (32 c ompounds) was determined with respect to the induction of lysogenic st rain prophage, influence of permeability reactions in a rabbit skin te st and cytotoxic changes of monolayers of Vero cells. The culture filt rates were prepared by 1-d cultivation of Salmonella typhimurium in a synthetic culture medium under conditions of intensive aeration at 37 degrees C after addition of subinhibitory concentrations of organic am monium salts. The results showed that substances of the homologous ser ies of 2-(10-undecenoyloxy)ethyl-alkyldimethylammonium bromides were c haracterized by a prophage-inducing effect in lysogenic strain cells. The induction of prophage raised with rising concentrations of subMICs of the substances, and its titer in the culture filtrates was mostly 4.10(6) PFU/mL. Substances C3, C9 and C12 of the same homologous serie s had the strongest effect on the permeability reaction in rabbit skin in 1/2 MICs. One-half MICs of four substances (B14, C3, C12, C14) and 1/4 MICs of substance A16 influenced cytotoxic changes on Vero cells, the other substances were ineffective.