Further Studies on Corynebacterium Species Capable of Producing Diphtheria Toxin (C. diphtheriae, C. ulcerans, C. ovis)

Abstract

SUMMARY Lysogenization experiments showed that diphtheria phages can induce the production of diphtheria toxin in strains of Corynebacterium ulcerans and C. ovis. In addition to diphtheria toxin, lysogenic C. ulcerans and C. ovis strains each produce their own specific toxin; they also maintain their specific morphology and urease production whilst C. diphtheriae strains lysogenized by C. ulcerans phagesproduce only diphtheria toxin. The majority of C. ulcerans phages are unable to induce the production of diphtheria toxin in strains of C. ulcerans. Phage typing with Corynebacterium ulcerans phages is a practical possibility. Thirteen well-defined phage types were established by this technique in 172 C. ulcerans and 62 C. ovis strains with only one of the phage types (111 C) occurring in both species. C. ulcerans can be distinguished from C. ovis by the pathogenicity test in mice. C. ovis kills mice by any route of inoculation whilst C. ulcerans strains cause only arthritis. C. ulcerans wild strains could be identified in this way and C. ulcerans and C. ovis strains from different type culture collections could be dis- tinguished from each other by these well-defined characteristics.