Infection of synovial fibroblasts in culture by Yersinia enterocolitica and Salmonella enterica serovar enteritidis: Ultrastructural investigation with respect to the pathogenesis of reactive arthritis

Synovial fibroblasts were infected with Yersinia enterocolitica or Salmonel la enterica serovar Enteritidis and analyzed by electron microscopy and flu orescence in situ hybridization. Intracellular bacterial replication was fo llowed by degradation leading to "ghosts" possessing lipopolysaccharides bu t not DNA. However, single bacteria survived for more than 2 weeks. Therefo re, transient intra-articular infection might be the missing link between i nitial intestinal infection and late synovial inflammation in the pathogene sis of reactive arthritis.