Immunoinformatics design of B-cell multi-epitope peptide for the diagnosis of Methicillin Resistant Staphylococcus aureus (MRSA) infection

Abstract

Background: Methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA) remains a significant clinical and epidemiological pathogen in hospital settings and in the community world-wide. The resistance to methicillin in Staphylococcus aureus is mediated by the mecA gene, which encodes penicillin-binding protein 2a (PBP2A). Rapid patient screening for MRSA is essential for infection control procedures in order to possibly enhance the outcomes of infected patients. In this study, we utilized PBP2A to predict and create a novel synthetic protein with multiple immunodominant B cell epitopes for rapid diagnosis of MRSA using an in-silico approach. Methods: Seven putative PBP2A peptides were used to analyze the protein’s primary, secondary, and tertiary structures (BepiPred). The B cell construct was then evaluated using I-TASSER server, and physicochemical properties, and homology modeling of the 3 D structure of the protein were obtained. Results: In silico analyses revealed regions with high immunogenicity. Altogether, 19 consented epitopes were selected for the in-silico succession; three consented epitopes from ALJ10988.1, three from ORN56903.1, three from AFJ06714.1, one from AEO00772.1, three from WP_000721309.1, three from WP_057521704.1, and three from WP_063851348.1. The constructs have an average length of 503 amino acids, molecular weight of 55,151.78, instability index of 41.44, theoretical PI of 9.28 and a C score −1.50. In addition, the parameters that were examined indicated the newly multi-epitope construct could potentially serve as a theoretical framework for the development of a MRSA diagnostic kit. Conclusions: Overall, we have developed an antigen-based multi-epitope peptide for the rapid and accurate diagnosis of MRSA infection through an in-silico approach, acceptable in terms of antigenicity, physicochemical properties, structural stability and strong immunogenicity.