CHARACTERIZATION OF THE ACTION OF LYSOZYME ON STAPHYLOCOCCUS AUREUS AND ON MICROCOCCUS LYSODEIKTICUS

Abstract

With M. lysodeikticus. electron microscopic observation showed that lysozyme first causes an enlarging or swelling of the cell, followed by a rupture of the cell wall with a dispersal of the cell contents. With the exception of 2 cell bodies (nuclei?), the cell contents dissolve in the medium. Finally the cell membrane is also destroyed leaving only the cell bodies. Turbidity, viable count, and direct count all reflect the rapid dissolution of the cells observed with the electron microscope. S. aureus is not so sensitive to the action of lysozyme, and in addition a different type of cell destruction is observed. At no time is there any evidence of the splitting of a cell wall. Rather, a slow dissolution of an outer viscous portion of the cell takes place over a period of several hrs. leaving an inner more dense portion. The viable count continues to decrease, reaching very low levels. In contrast, the direct count remains high, probably because of visualization of the cell masses. Attention is directed to precautions that must be exercised in preparing mounts for photomicrographs of materials undergoing enzymatic changes.