Subunit 76-kDa surface protein of Methicillin-Resistant Staphylococcus aureus (MRSA) is potentially useful for MRSA diagnostic tool

Objective: To evaluate the diagnostic performance of the polyclonal antibody generated from the subunit surface protein of MRSA for MRSA detection. Methods: The MRSA clinical isolates were identified by the cefoxitin disc diffusion test and confirmed by mecA PCR. The surface protein from the clinical isolates of MRSA was extracted and characterized with hemagglutination and adherence inhibition assays. Polyclonal antibody against the selected protein was produced in mice and then used for Western blot experiments. Results: Four conserved surface protein bands (63, 76, 88, and 114-kDa) were found in each MRSA clinical isolate. Hemagglutination reaction was demonstrated by the subunit 76 and 114-kDa surface protein of MRSA at 1:32 dilution. Such proteins were identified as adhesive molecules in the enterocytes. The sensitivity and specificity of the polyclonal 76-kDa antibody in detecting MRSA were 94.59% and 85.14%, respectively, with the Kappa values fall under the interpretation of substantial agreement (0.752) with the gold standard, suggesting it is useful for MRSA detection. Conclusion: Subunit 76 and 114-kDa surface proteins of MRSA exhibit adhesive properties in mediating MRSA infection. The polyclonal antibody of 76-kDa generated from the surface protein of MRSA could be used as an alternative for the identification of clinical isolates suspected with MRSA infection.