A total 181 strains of Mycoplasma laidlawii isolated were subjected to typing by means of the growth inhibition test on agar plate with thirteen kinds of rabbit antisera. Furthermore, 45 strains of them were used in the biological examination, together with 15 PG strains, to find indeces for the typing of M. laidlawii. All the Mycoplasma isolates were classified into three sero-types and further types by the serological test, and into three bio-types by the biological examination. The serological typing was more favorable than the biological typing, since three or further sero-types were included in bio-type I. Therefore, it is advocated by the authors that the the strains of M. laidlawii can be classified into three sero-types, A, B, and C, which are distinctly different from one another antigenically. Sero-type A included two subtypes, one of which was a fermentative group and the other a non-fermentative group. Some groups could not be identified. This suggests the pressence of further serotypes of M. laidlawii. Sero-type A tended to be isolated mainly from the urogenital tract, and sero-type B and C mostly from the mammary gland. There was an unidentified strain which was cross antigenically with all the antisera used. This strain may be an interesting subject for further research. Additional work is necessary to determine the significance of the parasitic M. laidlawii in the living body.
View full abstract