PCR rapidly detects methicillin-resistant staphylococci periprosthetic infection.

Optimal treatment of methicillin-resistant staphylococcal periprosthetic infections is predicated on rapid and reliable detection of these organisms. Culture has served as the gold standard for identification of these organisms despite shortcomings with sensitivity and processing time. The objective of the current study was to investigate a polymerase chain reaction assay aimed at rapid genomic detection of methicillin-resistance in staphylococci (mecA gene). The feasibility of the molecular approach first was validated using a septic arthritis model consisting of 73 synovial fluid samples inoculated with methicillin-resistant staphylococci and four negative controls. MecA polymerase chain reaction then was done on 35 clinical samples from 18 patients obtained at the time of revision arthroplasty. Results of the polymerase chain reaction were compared with culture. MecA polymerase chain reaction successfully predicted the presence of methicillin-resistant staphylococci in the septic arthritis model. In the clinical samples studied, the polymerase chain reaction results were concordant with culture results in 34 of the 35 samples tested. The one discordant result represented a false-positive culture result. The molecular assay was processed in less than 5 hours compared with 2 to 3 days for culture. Detection of methicillin-resistant staphylococci involved in periprosthetic infections by the polymerase chain reaction is a rapid and reliable approach.