Molecular detection of Incidence MRSA isolates from Skin and Soft Tissue Infections

Abstract Introduction : MRSA is a global health concern due to its antibiotic resistance and its role in severe, often fatal skin and soft tissue infections in healthcare and community settings. Objective: The study focuses on detecting MRSA and assessing virulence-associated Cas genes in clinical isolates from skin and soft tissue infections. Method Among 100 SSTI patients studied, 20% had Staphylococcus aureus , 55% had other bacteria, and 25% showed no growth based on standard laboratory identification methods. Antimicrobial susceptibility testing by Viteck-2 system was done, and Molecular analysis by PCR showed diverse CRISPR-Cas subtypes. HRM spa genotyping recognised. Results and Discussion: Among the 20 cases, males were more frequently affected than females, with the highest infection rates observed in the 16–20 and 6–10 year age groups, although no significant association with sex or age was found. Antimicrobial susceptibility testing revealed high resistance to oxacillin, confirming the prevalence of MRSA, along with resistance to multiple other antibiotics, indicating widespread multidrug resistance. Molecular analysis showed diverse CRISPR-Cas subtypes, with significant associations between Cas subtypes and resistance to gentamicin and tetracycline. HRM spa typing demonstrated marked genetic diversity, identifying seven clonal complexes with predominant local lineages, highlighting endemic circulation and potential for increased virulence and antimicrobial resistance. Conclusion: The isolates showed high MRSA occurrence (100% oxacillin resistance) and resistance to some antibiotics. CRISPR-Cas analysis discovered genetic heterogeneity, with Cas4 most common, and specific links between Cas subtypes and resistance (gentamicin–Cas4, tetracycline–Cas10).HRM spa genotyping recognized seven clonal complexes, representing both local endemic motion and significant genetic variety, which may influence virulence and resistance patterns. The findings highlight the high MRSA burden, the diverse genetic landscape of S. aureus, and the probable role of CRISPR-Cas in resistance, the necessity for incessant surveillance and informed antimicrobial therapy.