Beyond Antimicrobial Resistance: mec-genes Detection as a Factor of Epidemiological Characterization Among Methicillin Resistant Staphylococcus aureus (MRSA) Isolates in a Tertiary Care Hospital, South India

Introduction: The global public health concern of Staphylococcus aureus (S. aureus) infection and its spread, particularly methicillin-resistant Staphylococcus aureus (MRSA), is exacerbated by the emergence of mec-genes, which are considered markers of MRSA. The study aims to isolate MRSA in clinical isolates and detect mec-genes using molecular assays, thereby enhancing infection control programs. Materials and Methods: The study involved 381 clinical samples processed by standard laboratory procedures and PCR was performed targeting 16S rRNA gene as a reference and then with nuc-gene to detect Staphylococcus aureus. Further, MRSA was confirmed by PCR (Polymerase Chain Reaction) amplification of S. aureus isolates by sub-typing mecA and mecC gene. Sensitivity and specificity of phenotypic methods was calculated using mecA gene PCR as the gold standard. Results: In the present study, 65.85% clinical isolates were found to have similar homology with Staphylococcus aureus. Uniplex PCR results showed that all 162 isolates with S. aureus-like phenotypes were detected as MRSA carrying mecA gene, but none of them was found to carry mecC gene for MRSA. P-value for both the methods was