George P. Kubica

Designation of Strain H37Rv as the Neotype of Mycobacterium tuberculosis

Strain H37Rv of Mycobacterium tuberculosis (Zopf) Lehmann and Neumann is typical of the species in growth characteristics, drug susceptibility, and biochemical activity. H37Rv is compared with the hypothetical median strain of M. tuberculosis and agrees with it in 70 of 71 characters. In comparison with other strains of tubercle bacilli, H37Rv has moderate virulence for guinea pigs and mice. This strain agrees well with Kochs original description of the tubercle bacillus; the few differences that do exist are discussed. The well documented history of H37Rv, coupled with its world-wide distribution and long use by mycobacteriologists, makes it most appropriate as the neotype of the species M. tuberculosis. The strain may be obtained from the Trudeau Institute, Inc., Saranac Lake, N.Y. 12983, as TMC 102 or from the American Type Culture Collection, Rockville, Md. 20852, as 27294.

DIFFERENTIAL IDENTIFICATION OF MYCOBACTERIA VI. MYCOBACTERIUM TRIVIALE KUBICA SP. NOV.

ABSTRACT A new species of nonphot ochromogen mycobacteria is described. Most of the strains examined have been isolated from man; however, because of their lack of relationship to human disease, the name Mycobacterium triviale Kubica is proposed. The physical and biochemical characteristics, serologic activity, and thin layer chromatographic pattern of this new species serve to distinguish it from other nonphotochromo-genic mycobacteria in Runyons Group III.