Mycoplasmas in cell cultures from rheumatoid synovial membranes

Ten strains of myocoplasmas were recovered from cultures of synovium or cultures inoculated with synovial fragments from rheumatoid arthritis and one from osteo-arthritis. The source of the organisms is not known. Patients with rheumatoid arthritis had no complement-fixing antibody and no fluorescent staining antibody against the mycoplasmas isolated and no mycoplasma antigen was detected by immunofluorescence in sections of synovia and in synovial fluids.The strains isolated were of two main serological types and could be distinguished by direct fluorescent antibody staining from standard types of human commensals and the common tissue-culture contaminants. One may be Mycoplasma laidlawii.