Characterization of Methicillin-resistant Staphylococcus aureus Strains and Profiling of Panton–Valentine Leukocidin Virulence Gene in Pyogenic Infections from Patients Attending a Tertiary Care Center in North India

Abstract Background: Methicillin-resistant Staphylococcus aureus (MRSA) remains a significant healthcare concern, particularly in pyogenic infections. The presence of Panton–Valentine leukocidin (PVL) virulence gene and its correlation with antibiotic resistance patterns necessitate comprehensive characterization for effective treatment strategies. Methods: A study at a tertiary care center over a year collected pus and soft tissue infection samples. MRSA screening was performed using the cefoxitin disk diffusion test and the Kirby–Bauer disk diffusion method. Molecular characterization involved detecting mecA and PVL genes using gel-based multiplex polymerase chain reaction . Results: A total of 1469 pus and soft tissue infection samples were processed, out of which 896 pathogen-positive samples, among which 353 nonrepetitive S. aureus isolates were identified, of which 143 (40.5%) were MRSA. From these MRSA isolates, 49.6% (71/143) were PVL-positive. Sensitivity patterns of drugs are ciprofloxacin (13.2%), erythromycin (16.7%), levofloxacin (20.2%), clindamycin (43.3%), doxycycline (45.4%), ampicillin/sulbactam (62.9%), amikacin (72.2%), and teicoplanin (79.7%). Vancomycin resistance was not observed. Among PVL-positive strains, 55.55% exhibited hyperviscous characteristics. Community-acquired MRSA infections (CA-MRSA) showed higher PVL positivity compared to healthcare-acquired–MRSA (HA-MRSA) infections. Conclusion: The study highlights the high prevalence of MRSA in pus and soft tissue infections, with nearly half being PVL-positive. High resistance rates were observed for other antibiotics, particularly ciprofloxacin, erythromycin, and levofloxacin. CA-MRSA infections had a higher PVL positivity rate.