Rapid diagnosis of septic arthritis using 16S rDNA PCR: a comparison of 3 methods.

Few studies address the utility of molecular techniques for diagnosis of infection in synovial fluid (SF). We evaluated 3 different methods using 16S rDNA polymerase chain reaction (PCR) on 63 specimens for the diagnosis of joint infection. SF samples were classified as normal, inflammatory, or septic based on the patient's clinical and laboratory results. Samples were analyzed by conventional PCR using primers for the bacterial 16S rDNA gene and by real-time PCR utilizing 2 different sets of primers for the target gene 16S rDNA. PCR results were compared to culture results. All inflammatory and normal SF samples were culture negative. There was concordance with 10 of the 16 septic samples by 2 of the PCR methods. When comparing 3 methods for rapid detection of septic arthritis, real-time PCR using SYBR-Green I and conventional PCR demonstrated favorable test characteristics, but need further study.