Detection and Molecular Characterization of Methicillin-Resistant Staphylococcus aureus (MRSA) in a Tertiary Care Hospital: A Review

Abstract

This study reviews the detection, antimicrobial resistance patterns, and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary-care hospital setting. The review synthesizes findings from 274 clinical specimens collected over a five-month period, yielding 106 confirmed S. aureus isolates identified using conventional microbiological methods and the Vitek 2 automated system. Phenotypic antimicrobial susceptibility testing against 18 antimicrobial agents demonstrated substantial multidrug resistance, with resistance to oxacillin and cefoxitin detected in 93.4% and 87.7% of isolates, respectively. Molecular analysis using polymerase chain reaction (PCR) investigated key genetic determinants, particularly mecA, which encodes the altered penicillin-binding protein PBP2a responsible for beta-lactam resistance, and hlg, a gene associated with gamma-haemolysin production and virulence. The study highlights the importance of combining phenotypic susceptibility testing with molecular surveillance for accurate MRSA detection and characterization. It also emphasizes the need for strengthened hospital infection-control practices, continuous antimicrobial-resistance surveillance, and responsible antimicrobial stewardship to limit the spread and clinical impact of multidrug-resistant MRSA.