PREVALENCE AND MULTIDRUG RESISTANCE PROFILING OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA) ISOLATED FROM CLINICAL SPECIMENS IN TERTIARY CARE HOSPITALS OF PESHAWAR

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) remains a critical challenge in clinical settings due to its extensive multidrug-resistance profiles. This study aimed to isolate, identify, and determine the antibiotic susceptibility patterns of MRSA strains obtained from various clinical wards at Lady Reading Hospital (LRH) and Khyber Teaching Hospital (KTH) in Peshawar, Pakistan. Methodology: Clinical samples were processed using the spread plate technique on Nutrient Agar. Suspected colonies were subjected to Gram staining and a battery of biochemical tests, including catalase, coagulase, methyl red, and urease assays. MRSA confirmation was performed using Oxacillin and Methicillin resistance tests, alongside Cefoxitin (30 μg) disc diffusion as per Clinical and Laboratory Standards Institute (CLSI) guidelines. In vitro antibiotic susceptibility against ten different therapeutic agents was evaluated using the Kirby-Bauer disc diffusion method.  Results: Out of 25 initial suspected S. aureus isolates, 5 strains (20%) were confirmed as MRSA. All five confirmed strains (LRH-01, LRH-07, LRH-11, KTH-04, and KTH-09) were Gram-positive cocci and exhibited positive reactions for catalase, coagulase, methyl red, and beta-hemolysis. The antibiogram revealed significant resistance across multiple antibiotic classes. High levels of resistance were observed against Minocycline (80%), Cefotaxime (80%), Aztreonam (60%), and Azithromycin (60%). Conversely, the isolates demonstrated higher sensitivity toward Cefixime, Amikacin, and Ciprofloxacin. Notably, only one strain showed complete resistance to Cefixime and Amikacin, suggesting these may remain viable treatment options in local clinical settings. Conclusion: The study identifies a 20% prevalence of MRSA among suspected staphylococcal clinical isolates in the region. The high resistance to commonly used antibiotics like Cefotaxime and Azithromycin underscores the necessity for regular antimicrobial surveillance and the implementation of stringent infection control policies to manage the spread of resistant strains in tertiary care hospitals.

Keywords : MRSA (Methicillin-Resistant Staphylococcus aureus)Antibiotic Susceptibility, Antibiogram, Clinical Isolates,Multidrug Resistance (MDR)