The Action of Cationic Detergents on Bacteria and Bacterial Enzymes

Abstract

The bactericidal action of the quaternary ammonium detergents has not yet been satisfactorily explained. Recent reviewers (Putnam, 1948; Rahn and Van Eseltine, 1947; cf. Glassman, 1948) have not agreed that the amounts of these detergents lethal to bacteria are insufficient to cause any general denaturation of the bacterial proteins (Valko, 1946). Action by enzyme inactivation, either primary or secondary to some other injury, has been repeatedly suggested. Respiratory and glycolytic activity is depressed by detergents, and the inhibiting amounts were later shown to parallel roughly the lethal amounts (Baker et al., 1941a,b). However, the frequent survival of cells at concentrations of detergent which produced marked respiratory inhibition has cast doubt on an action by direct inhibition of enzymes. Hotchkiss (1946) demonstrated that nitrogen and phosphate compounds diffuse out of the cells with bactericidal amounts of 1 This investigation was conducted under a contract of Dr. D. E. Green and Columbia University with the Committee on Medical Research of the Office of Scientific Research and Development and at the request of the Office of the Quartermaster General.

Studies on Cell Surface-Germicide and Enzyme-Germicide Reactions and Their Contribution to the Lethal Effect

“…Inhibition of glucose oxidation may be due to general protein denaturation, but effects on coenzymes and, perhaps, activating ions may also be significant. The importance of loss of enzyme activity in the overall lethal effect found here confirms the conclusions of Knox et al (1949).…”

“…Under certain conditions, the addition of the quaternary ammonium compound (QAC), p-diisobutylphenoxyethoxyethyl dimethyl benzyl ammonium chloride, to thick suspensions of S. marcescens produces a striking lytic effect. Table 1 illustrates the pattern of lysis using weight ratios of germicide to cells as emphasized by Knox et al (1949). Cell density and the weight ratio of QAC to cells affect strongly the total amount of lysis obtained, the latter becoming negligible when the cell density or ratio is sufficiently reduced.…”

“…On the other hand, other physicochemical effects of quaternary ammonium germicides, especially protein denaturation and enzyme inhibition, have been implicated in the bactericidal mechanism. Knox et al (1949), Lawrence (1950), Valko (1946, and Rahn and Van Eseltine (1947) have reviewed briefly opinions on these and related points.…”

“…In addition, simultaneous determinations of survival, enzyme inhibition, and cell lysis have not been run under identical conditions in most instances. In spite of a number of claimed correlations between germicidal activities and cell lysis (Hotchkiss, 1946;Taylor, 1946, 1947;Salton, 1950Salton, , 1951 or enzyme inactivation (Knox et al, 1949), it appeared necessary to review the matter using methodological modifications designed to eliminate the above objections.…”

Effects of a Quaternary Ammonium Compound on Escherichia coli1

“…Hotchkiss (1946), Gale and Taylor (1947), and Salton (1950and Salton ( , 1951 demonstrated leakage of cellular constituents caused by quaternary ammonium compounds. Knox et al (1949) implicated the role of detergent-sensitive enzymes in the lethal effect. More recently, Stedman, Kravitz, and King (1957) studied the role of lysis and enzyme inhibition under similar conditions.…”