C-189. Joint Infection Caused by Salmonella enteritidis, and Identification of Salmonella Using Broad Range PCR and Pyrosequencing Technology

H. Kobayashi, M. J. Tuohy, G. S. Hall, U. Knothe, M. Oethinger, T. Kawamoto, G. W. Procop, T. W. Bauer;
The Cleveland Clin., Cleveland, OH.

Background: Periprosthetic infection is an important complication of joint arthroplasty, but infection with Salmonella is very rare. We describe a case of Group D Salmonella enteritidis infection involving a total knee arthroplasty. Additionally, the 16S rRNA gene sequence of DNA extraction from the joint fluid was evaluated by Pyrosequencing (Biotage AB, Uppsala, Sweden). Case Report: A 71-year-old woman who had previously undergone bilateral total knee arthroplasty developed pain in both knees during the 2 weeks prior to her visit to our emergency department. Physical examination revealed tenderness to palpation, swelling, increased warmth and limited range of motion of both knees. Left knee joint aspiration produced cloudy fluid with 121×109 WBC /L, with 92% neutrophils. Gram stain revealed no microorganisms. A blood culture showed no growth. Therapy with intravenous Ciprofloxacin was initiated. After 2 days, the joint fluid culture grew Salmonella enteritidis. Bilateral total synovectomy was performed, the joints were irrigated, and the polyethylene tibial components were replaced. Intraoperative cultures from both knees again grew Salmonella. The patient was discharged home in stable condition. Abdominal CT and ERCP showed no positive findings for the source of the Salmonella. Methods: DNA extraction of the aspirated joint fluid was performed using MagNA Pure LC DNA Isolation Kit III (Roche Diagnostics, Indianapolis, Ind). A broad-range real-time PCR was used for amplification of a portion of the 16S rRNA gene (RotorGene 3000, Corbett Research, Australia). The forward primer was biotinylated for pyrosequencing and a sequence primer was used to sequence a 30 bp hypervariable region of the amplicon. Identifications were made using NCBI GenBank sequences. Results: The 30 bp sequence by pyrosequencing completely corresponded with the sequence of Salmonella enteritidis. Conclusion: Salmonella is an uncommon cause of joint infection. As far as we know, this is the first report of identification of almonella in joint fluid using Universal PCR following by pyrosequencing.