[Behavior of disinfectant substances in comparisons of bacterial strains]

Following a brief of the main requisites of disinfectants, the solutions tested during research are listed: 1) Ethyl alcohol denatured at 70 degrees C. 2) A hydro-alcoholic solution of 0,20% Benzalkonium chloride (F.U.) in association with 0.15% 1-Benzyl-3 [3-Dimethylammoniopropoxy]-1 H-indazol HCl. 3) An acetonic hydro-alcoholic solution of 0.1% Benzoxonium chloride, a water solution of 1% Polyvinylpyrrolidone-iodine (P.V.P.-I), a water solution of 0.5% Chlorhexidine gluconate, and a hydro-alcoholic solution of 0.17% Benzalkonium chloride. The technique used (modified contact test) is illustrated and the results analysed in detail. The best results absolutely were obtained by applying Ethyl alcohol denatured at 70 degrees C and P.V.P.-I in a water solution at a concentration of 1%. Some problem must, however, be borne in mind when using such substances (first, denaturing of proteins, second, action curtailed by temperature). Best results among the Q.A.C. were obtained with the hydro-alcoholic solution of an association of 0.20% Benzalkonium chloride (F.U.) and 0.15% 1-Benzyl-3 [3-Dimethylammoniopropoxy]-1 H-indazol HCl.