Antimicrobial actions of hexachlorophene: release of cytoplasmic materials.

Intracellular solutes were released from growing or resting cells of Bacillus megaterium as a consequence of hexachlorophene treatment. The effect was dose dependent, with the optimum at a concentration about sevenfold greater than the minimal lethal dose. The effects of pH and temperature on the leakage process also were inconsistent with the killing effects of the drug. The types of materials released appeared to be the same with or without hexachlorophene treatment. The released materials were small molecules which apparently derived from preexisting ribonucleic acid and protein, but not from deoxyribonucleic acid. Compared to the effects of other representative surface-active agents and other bis-phenols, hexachlorophene was superior in ability to cause leakage of intracellular materials. Different microorganisms varied in their susceptibility to hexachlorophene, with Pseudomonas aeruginosa and a paracolon isolate the most resistant of the vegetative cells examined. It was concluded that the release of intracellular solutes was an effect secondary to the lethal event and presumably arose from hexachlorophene-mediated stimulation of degradative enzymes.