Biochemical And Molecular Analysis of Staphylococcus Aureus Clinical Isolates from Hospitalized Patients

Background: The most common hospital-acquired infection is caused by antibiotic-resistant and virulent Staphylococcus aureus. This study will characterize S. aureus clinical isolates from hospitalized patients’ biochemical and molecular profiles to understand resistance mechanisms and harmful potential. Methods: The trial ran from September 2023 to October 2024 at Jawaharlal Nehru Medical College & Hospital in Bhagalpur, Bihar. Clinical samples included pus, blood, wound swabs, and respiratory secretions from six patients per month. S. aureus was isolated and identified biochemically using standard microbiological procedures. Polymerase chain reaction was used to analyze resistance and virulence genes (mecA, vanA, spa, and pvl) and the Kirby-Bauer disc diffusion method was used to determine antibiotic susceptibility. Results: We analyzed 72 S. aureus isolates. 50% of isolates were methicillin-resistant, 60% cefoxitin-resistant, and 10% vancomycin-resistant. The vanA gene was found in 15% of isolates and the mecA gene in 55%. Virulence-associated genes spa and pvl were found in 75% and 35% of isolates, indicating pathogenic potential. Erythromycin and clindamycin resistance were 40% and 30%. Conclusion: This study highlights the high prevalence of antibiotic resistance and virulence factors in S. aureus clinical isolates from hospitalized patients. The findings emphasize the need for robust molecular surveillance, effective antimicrobial stewardship, and stringent infection control practices to combat the burden of S. aureus infections in healthcare settings.