Observations on the Group C Streptococcal Bacteriophage and Lytic Enzyme System

Abstract

Fox, Eugene N. (La Rabida-University of Chicago Institute, Chicago, Ill.), and Masako K. Wittner . Observations on the group C streptococcal bacteriophage and lytic enzyme system. J. Bacteriol. 89: 496–502. 1965.—The phage-associated lytic enzyme of group C streptococci was assayed by measuring the solubilized portion of radioactive cell walls. By this sensitive assay system, the induced synthesis of the lytic enzyme was observed intracellularly during phage infection; at least half of the total enzyme was synthesized and remained intracellular during the eclipse period, and was then released with the liberation of mature phage. Lytic enzyme could be detected in only two of eight lysogenic strains during temperate-phage production after ultraviolet induction. Virulent phage purified by density-gradient centrifugation contained lytic enzyme presumably associated with the virus per se . No hyalyronidase was detected in association with the phage, nor was this enzyme induced during phage synthesis. Variant strains of group C streptococci, no longer serologically active, were isolated as phage-resistant mutants. These strains still adsorbed the phage, but without subsequent virus reproduction, indicating that the group polysaccharide was not the primary receptor for the virus.