ABSTRACT
A pathologic event in humans or animals that involves the participation of two or more species of mycobacteria may be designated as a mixed mycobacterial infection. In the majority of cases of such mixed infection, Mycobacterium tuberculosis is found with one of the atypical mycobacteria. The allergic and immune reactions produced by Mycobacterium simiae, Mycobacterium asiaticum, and Mycobacterium chelonei in guinea pigs was studied. Sensitins that were prepared from cultures of these microorganisms were species specific, producing intensive cutaneous reactions in the animals infected with these organisms. Animals that received atypical mycobacteria and were infected secondarily with bacille Calmette-Guérin (BCG) had a positive reaction to tuberculin H37Rv PPD-S, but the sensitivity of such animals to the atypical strains was not altered. The atypical strains studied have no immunogenic power against tuberculosis, and they reduced the immunizing power of BCG, probably by exerting an immunosuppressive effect.
Subject(s)
Mycobacterium Infections/immunology , Animals , BCG Vaccine/immunology , Guinea Pigs , Immunization , Nontuberculous Mycobacteria/immunology , Tuberculosis/immunologyABSTRACT
Fifty mycobacterial strains were isolated from freshly imported tuberculin-negative Macacus rhesus and Cercopithecus ethiops monkeys. Of these strains, 14 were identified as Mycobacterium simiae and 4, as Mycobacterium asiaticum. These two species are slow growing with a delayed photochromogenicity. M. Simiae is niacin-positive. Both species are resistant to the antituberculous chemotherapeutic compounds streptomycin, isoniazid, p-aminosalicylate, and rifampin but are sensitive to cycloserine. The two species are virulent for white mice. Infection is contagious; 25% of noninfected cage mates become infected during 12--60 days of exposure to infected animals. Intrauterine transmission of infection also occurs. Utilizing the gel-precipitation method, we have observed up to 16 antigens in each species. Four to six antigens are shared with Mycobacterium tuberculosis. Mycobacterium species strain 52 is antigenically distinct. The 14 strains of M. simiae belong to two serotypes. Mycobacterium habana belongs to M. simiae serotype 1.
Subject(s)
Haplorhini/microbiology , Mycobacterium/isolation & purification , Nontuberculous Mycobacteria/isolation & purification , Animals , Mice , Mice, Inbred BALB C , Nontuberculous Mycobacteria/immunology , Nontuberculous Mycobacteria/pathogenicityABSTRACT
The synthesis of Vitamin B12 by five reference strains of species of mycobacteria, the influence of cobalt upton the synthesis and the correlation between the phase of growth and quantitative biosynthesis of Vitamin B12 were studied. Assays were performed on cell extracts and culture filtrates using Lactobacillus leichmannii ATCC7830 (tube method). All five species synthesized Vitamin B12, which could be deomonstrated both in cell extracts and in the culture filtrates. An optimum accumulation of Vitamin B12 by BCG and M. phlei could be observed on the 30th day of cultivation. Addition of cobalt did not influence the growth of BCG and M. phlei, but markedly enhanced the production of Vitamin B12. Cells contained much more Vitamin B12 than culture filtrates did. Vitamin B12 levels in M. smegmatis, M. fortuitum and M. asiaticum were lower than those in BCG and M. phlei.
