Interactions of cultured rat synovial and ocular ciliary body cells with two strains of Mycoplasma arthritidis.

Strains of Mycoplasma arthritidis differ in their ability to cause joint and ocular inflammations. Although the reasons for this difference are not fully understood, pathogenic mycoplasmas commonly require close associations with the cells they damage. Using 3H-uridine labeled mycoplasma, we compared cellular interactions of in vitro cultivated rat synovial and ocular ciliary body epithelial cells with two American Type Culture Collection strains of M. arthriditis shown to differ in their virulence. Radiolabeling assays gave evidence of a stronger retention capability on cultured cells by the more pathogenic strain, 14152. Scanning electron microscopy demonstrated cellular associations with the two strains of mycoplasma, with more of the 14152 adhering to both cell types. Examination by transmission electron microscopy showed evidence of contact between the more virulent 14152 strain and both cell types, but no similar evidence with the comparatively less virulent strain, 19611. The pathogenicity of different strains of M. arthritidis may vary according to their ability to closely associate with specific target cells involved in the disease process.