Factors Influencing Pathogenicity of Mycoplasma arthritidis (PPLO). ∗

Abstract

Summary

The ability of Mycoplasma (PPLO) to produce polyarthritis in rats has been modified in vitro and in vivo. Pathogenic PPLO recovered from Murphy-Sturm lymphosarcomas became non-virulent upon repeated subculture in commercial media, but the pathogenic properties were restored and maintained by addition of cell- and bacteria-free extract of the tumor tissue. Growth of Mycoplasma in tumor tissue in vivo also restored the pathogenic property. Diffuse and clonal forms of the pathogenic PPLO were isolated. Twice as much interphalangeal polyarthritis followed injection of the diffuse as the clonal form. Prior PPLO arthritis resulted in immunity. Passive transfer of the immunity was accomplished with serum but not with splenic cells.