Genotypic analysis of Methicillin (mecA) and Vancomycin (vanA) resistance in clinical isolates of Staphylococcus aureus

a species of bacteria which can cause adverse illnesses, from mild infections to severe diseases. The Antimicrobial Resistance (AMR) of S. aureus varies by geographic location, time and population. The present study was designed to estimate the frequency of 16s rRNA, mecA and vanA genes in S. aureus which isolated from clinical specimens using polymerase chain reaction (PCR) in south of Iraq. Materials and Methods: The current study was conducted in Al-Hussein Teaching Hospital, Bint Al-Huda Hospital in Al-Nasiriyah for the period from December 31, 2023 to April 20, 2024. The S. aureus were isolated from patients with urinary tract infections (UTI) and burns. Diagnosis of S. aureus was carried out by VITEK2 after subculture and purification. All isolate were examined for the presence of 16s rRNA, mecA and vanA genes using PCR technique. Results: The current study included 50 isolates, 32 (64%) of which were positive for S. aureus. All isolates were positive of 16s rRNA and mecA genes, however the vanA gene was positively detected in 2 (6.25%) of S. aureus isolates. Conclusion: The present study concluded that the resistance of Staphylococcus aureus to methicillin was very high, while its resistance to vancomycin was very rare.