Virulence Gene Profile and Antimicrobial Susceptibility of Staphylococcus aureus Clinical Isolates from the United Arab Emirates

Staphylococcus aureus causes infections ranging from skin and soft tissue infections to life-threatening systemic disease. The convergence of virulence determinants with antimicrobial resistance, particularly in methicillin-resistant S. aureus (MRSA), complicates management. In the United Arab Emirates (UAE), S. aureus is a major contributor to community- and hospital-acquired infections, and regional surveillance from the Gulf Cooperation Council has documented a shift toward community-associated MRSA lineages. Despite this clinical burden, granular molecular epidemiological data from the UAE remain scarce. Fifty consecutive S. aureus clinical isolates were obtained from Thumbay Laboratories, Ajman, UAE (October 2022–August 2023). Identification and antimicrobial susceptibility testing against 23 agents were performed on the MicroScan WalkAway system. Five virulence genes, namely mecA, Panton-Valentine leukocidin (PVL; lukF-S), exfoliative toxins A (eta) and B (etb), and toxic shock syndrome toxin (tst), were detected by conventional PCR. PVL was the most prevalent virulence gene (48%, 24/50), detected exclusively in pus isolates. mecA carriage, confirming MRSA, was identified in 44% (22/50), with PVL–mecA co-occurrence in 22% (11/50). eta was present in 6% (3/50), and etb and tst each in 2% (1/50). Resistance was highest for ampicillin and penicillin (86% each), while full susceptibility (100%) was retained for vancomycin, linezolid, daptomycin, teicoplanin, rifampin, Synercid, and trimethoprim. mecA carriage was significantly associated with resistance to amoxicillin, clavulanate, ampicillin, imipenem, penicillin, oxacillin, azithromycin, erythromycin, and ciprofloxacin (p < 0.05). This study provides the first integrated molecular characterization of key S. aureus virulence determinants, along with a comprehensive antimicrobial susceptibility profile in the UAE. The high PVL prevalence and substantial MRSA burden highlight the need for structured regional surveillance and antimicrobial stewardship, while retained susceptibility to last-resort agents offer actionable guidance for empirical therapy.