BACTERIOPHAGE SUSCEPTIBILITY AND TUBERCULIN SPECIFICITY OF UNCLASSIFIED MYCOBACTERIA

Abstract

Ten strains of unclassified mycobacteria were examined for their phage susceptibility, tuberculin specificity, and susceptibility to potassium tellurite. None of the unclassified mycobacteria used in this experiment were susceptible to any of 10 mycobacteriophages, while many strains of the other types of mycobacteria except avian bacilli were susceptible to one or more mycobacteriophages. Nine strains of mycobacteria isolated from lymph nodes of dogs were also tested for phage susceptibility. Five strains with R-type colonies showed a similar phage-susceptibility pattern to human strains, while the remaining 4 strains with S-type colonies were resistant to all of the phages tested. The unclassified strains showed the same degree of susceptibility to potassium tellurite as the avian strains. Cross-tuberculin reactions using purified tuberculin protein [pi] revealed that unclassified strains of the photo -chromogen group and those of the nonchromogen group have their own respective group specificity. The human strain was more closely related to the photochromogens than to nonchromogens in tuberculin specificity. On the other hand, the tuberculin specificity of the nonchromogens was almost identical to that of avian strains. It may be concluded from these facts that nonchromogens are closely related to avian strains of tubercle bacilli.