Detection of Salmonella infantis in synovial fluid cells of a patient with reactive arthritis.

We investigated a patient with Salmonella infantis triggered reactive arthritis (ReA) for a possible occurrence of S. infantis-specific antigens and DNA in the synovial fluid (SF) cells. S. infantis-specific antigens were abundantly observed by immunofluorescence in SF cells of the patient during acute joint inflammation. Salmonella-specific DNA was detected by Southern blotting of the amplified polymerase chain reaction product once, but the result could not be repeated. It seems that if bacterial DNA exists in inflamed joints in Salmonella triggered ReA, its amount is extremely low. This is the first report of intraarticular S. infantis antigens and potentially of Salmonella DNA in Salmonella triggered ReA.