PRODUCTION OF A POLYSACCHARIDE BY STAPHYLOCOCCUS AUREUS. 3. ACTION OF PENICILLINS AND POLYSACCHARIDES ON ENZYMIC LYSIS.

Abstract

Summary1. The resistance of S. aureus to lysis by lysozome and trypsin was abolished by exposing growing cells to subinhibitory concentrations of nafcillin. This observation, together with the results of electron microscopic studies of nafcillin-treated cells exposed to maximal enzymatic action, reflect an actual interference with cell wall synthesis. 2. Although the precise cytological action of the subinhibitory levels of the penicillins on the integrity of the cell wall is not known, the limited lytic action of lysozyme on cells treated with oxacillin and cloxacillin, as well as the resistance of these cells to further lysis by trypsin, suggest at least a quantitative difference between nafcillin and the other penicillins in the disorganization of the cell wall structure. 3. On the basis of the experiments described, evidence is presented which indicates that subinhibitory levels of nafcillin produce an alteration of cell wall structure, thereby increasing permeability and rendering the cell wall and p...