Action of Several Disinfectants on Yeasts.

Abstract

Ten strains of yeasts were subjected to the action of gentian violet, mercurochrome-220, iodine and acriflavine. The technic involved the use of a plate very much like that used by Churchman. The plate which we used, however, had 2 control areas instead of one. The agar containing the dye was added to the middle compartment, leaving one compartment on each side without the disinfectant. Gentian violet was studied in 3 ways: (1) application of the dye directly to the cells; (2) behavior of the organisms on dye-agar; and (3) attempts to raise the tolerance of the organisms for the dye. All of the cultures except one were susceptible to the presence of gentian violet. This organism, when stained according to Henrici's 1 technic for applying the Gram stain to yeasts, was Gram negative. The observation that 9 of the yeasts were Gram positive explains their inability to endure the presence of gentian violet. It was found that when the dye was employed at a dilution of 1 to 80,000 no growth appeared on the dye media even after several days'incubation. On the other hand, a dilution of 1 to 140,000 allowed very slow growth after from 3 to 4 days incubation. Raising the temperature greatly increased the action of the dye. Attempts to raise the tolerance of yeasts to gentian violet were successful although the extent varied for each strain. These results indicate that yeasts, like bacteria, can be divided into two groups depending on their reaction to the Gram stain. Others who worked on this subject are E. B. Clark 2 and Fa her and Clark. 3 Our results confirm their conclusions.