Mechanism Of Phage-Induced Lysis In Pneumococci

Abstract

Earlier studies suggested the possible role of host autolytic enzyme in the release of progeny phage from Dp-1 infected pneumococci. Several new experiments reinforce this notion. Specifically, the resistance of an autolysis-defective mutant to infection at low phage to cell ratios could be eliminated by prior coating of the host bacteria with pneumococcal autolysin isolated from wild-type cells. Productive infection was also possible by lowering the temperature of incubation to 30.degree. C, a condition that leads to a partial activation of the thermosensitive residual autolysin in the mutant cells. Other experiments clearly indicate the role of the newly discovered phage-associated lysin (PAL), reported in the accompanying communication, in bacteriophage release and culture lysis; specifically, lysis was stimulated by reducing agents and inhibited by cardiolipin. The host-related and the PAL activities are apparently involved with Dp-1 induced lysis of pneumococci.