Mycoplasma pulmonis Arthritis in Mice: Microbiological and Immunological Features

Mycoplasma pulmonis m53 was inoculated intraarticularly in the bilateral hind footpads and bilateral knee joints of BALB/c mice. Mycoplasmas were recovered from the affected joints over 20 weeks accompanying acute or subacute inflammation. Intensive deposition of immunoglobulins, a complement (C3) and mycoplasma cell antigens occurred in synovial and adjacent connective tissues. The histopathologically intact kidneys, brain, and lungs showed deposition of IgG and the complement on the endothelial cells of blood vessels. An IgG-rheumatoid factor like substance (RFLS) was detected in the serum of the mice by an enzyme-linked immunoabsorbent assay. Persistence of mycoplasma cells and immune complexes in the articular tissues might cause the prolongation of inflammatory responses in murine mycoplasmal arthritis.