Second-round PCR products produced by the synovial fluid samples which were treated with primer pair *8A-5B. Lanes 1 and 2, samples from OA patients; lane 3, sample from a gout patient infected with M. fermentans; lane 4, samples from an AS patient infected with M. fermentans; lanes 5 and 6, samples from RA patients infected with M. fermentans; lane 7, molecular size ladder.