Biochemical Characterization and Antigenic Relationship of Mycoplasma mycoides subsp. mycoides, Freundt and Mycoplasma mycoides subsp. capri (Edward) Freundt

Abstract

Forty-seven bovine, caprine, and ovine Mycoplasma strains were studied. Fifteen of these were M. mycoides subsp. mycoides Freundt; the remaining 32 were previously designated as M. mycoides subsp. capri (Edward) Freundt, M. agalactiae (Wroblewski) Freundt, or Turkish type C. Cultures of these strains were obtained from various laboratories abroad and from the Plum Island Animal Disease Laboratory repository; they included representatives of species and serotypes previously reported. The purity of all 47 cloned strains was checked by a combination of differential inhibitory methods, cloning, characterization, and serological techniques. The strains were tested for glucose fermentation, tetrazolium reduction, arginine decarboxylation, film and spots formation, hemolysis of sheep erythrocytes, inhibitory effect of 0.02% methylene blue, and methylene blue reduction. All M. mycoides subsp. mycoides, M. mycoides subsp. capri, and related strains were biochemically and serologically compared with the other strains and with representatives of a recent classification of the entire group of caprine and ovine mycoplasmas. All of the 15 M. mycoides subsp. mycoides strains gave similar biochemical reactions. Among the 32 test Mycoplasma strains, 2 of sheep origin designated Ghaleh Morghi-16 and S-5-64 were previously misidentified as M. agalactiae; 4 other strains were identified as Turkish C type. All of these Mycoplasma strains were identified as belonging to caprine and ovine group 8. The 32 strains were divided into 2 serogroups. One group was comprised of 5 strains, including the type strain of M. mycoides subsp. capri (strain PG3), and the other group contained 27 strains, including a large number previously identified as M. mycoides subsp. capri. All of the strains in the latter group showed an antigenic relationship to M. mycoides subsp. mycoides, whereas the 5 strains of the first group were serologically distinct. The 32 strains including in these 2 groups and the 15 M. mycoides subsp. mycoides strains had no antigenic relationship to Mycoplasma agalactiae, M. arginini, Acholeplasma oculusi, or to 7 new groups of caprine and ovine Mycoplasmas. It is significant that some of the group 8 strains were isolated from goats and sheep in countries free of contagious bovine pleuropneumonia. Their antigenic identity to M. mycoides subsp. mycoides suggests that serious problems might arise if diagnosis of such cultures were made solely on a serological basis.