PHAGE-HOST RELATIONSHIPS IN NONTOXIGENIC AND TOXIGENIC DIPHTHERIA BACILLI

Abstract

C. diphtheriae bacteriophage obtained from Freeman contained a lytic phage, , and its temperate mutant [beta]. Phage B causes almost complete lysis of the indicator strains C4(C444) and C7(C770). Phage[beta], while causing partial lysis, is the active agent responsible for converting the indicator strains to their lysogenic, toxigenic derivatives, C4 ([beta]) and C7 ([beta]), which are resistant to lysis by phage B. In all other respects the behavior of B and [beta] phages is identical, i.e., effect of burst size and latent period on the indicator strains, rate of adsorption, stability, and rate of heat inactivation. [beta] -phage development in the C4([beta]) and C7([beta]) strains may be induced by u.-v. light irradiation. The classic P.W. 8 strain is also lysogenic and may be induced by irradiation. The phage liberated by P.W. 8 differs in its host range from B and [beta] phages. The conversion rate of C4 to C4 ([beta]1) has been detd. at different [beta]1, phage multiplicities.