GENETIC FACTORS IN CORYNEBACTERIUM DIPHTHERIAE CONVERSION

Abstract

A study was made of the relationship of Corynebacterium diphtheriae phage [beta], a phage capable of converting strain C4 to toxigenicity, and phage [gamma] , a nonconverting phage. These phages are related serologically, exhibit the ability to recombine, but fail to mutually exclude. It is concluded that [beta] and [gamma] phage are closely related. Analysis of the types of cells and phages present after exposure of C. diphtheriae strain C4([gamma]) to [beta] phage revealed 3 kinds of phage interaction. These were: (1) prophage substitution, (2) double lysogenization, and (3) recombination. Re-combinant types were found in which ability to convert to toxigenicity and host range segregated independently. Thus the discrete genetic character of converting ability in C. diphtheriae phage was shown.