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.

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.