Differential Lytic Response of Enterococci Associated with Addition Order of Lysozyme and Anions

Abstract

Suspensions of Streptococcus faecium , prepared by washing with and resuspending in water, were lysed slowly if sodium chloride was added prior to lysozyme; however, if brief incubation with lysozyme was followed by addition of sodium chloride, lysis was immediate and extensive. Relatively lysozyme-resistant strains of S. faecalis could be lysed readily by adding lysozyme first. The primary addition of lysozyme apparently resulted in a “sensitized” cell with a damaged wall, as evidenced by N -acetylhexosamine release. Anionic detergents could replace sodium chloride in lysing these sensitized cells. The difference in activity associated with the order of addition probably involved a competition for reactive sites on the cell surface.