Molecular Detection of Virulence Factors in Clinical Isolates of Staphylococcus aureus

الملخص

    The 16S rRNA gene demonstrated a high degree of diagnostic accuracy (100%) , which reinforces the reliability of the results . High prevalence rates were recorded for PVL (90%) and clfA (80%), indicating the presence of highly virulent strains and their impact on infection . The differences in results compared to other studies are attributed to several factors, including environmental factors , sample type, and geographic location . S.aureus is an opportunistic pathogen responsible for a wide range of infections, ranging from mild skin infections to serious systemic diseases. This study aims to identify virulence factors in S.aureus bacteria isolated from various clinical cases.  A total of 140 clinical samples were collected from patients admitted to Diwaniya Teaching Hospital between November 2025 and January 2026. The samples were diagnosed by microscopic examination and cultured on blood agar and menthol salt agar , followed by testing using the 16S rRNA gene and screening for virulence factors, including PVL and CLF-A, using PCR molecular methods. The results showed that 16S rRNA gene amplification was successful in 100 % of all samples. The PVL gene was detected in 18 out of 20 samples (90 %) , while the clfA gene was detected in 16 samples (80 %). These results indicate a widespread prevalence of virulence factors in the isolates included in the study. The study confirms the effectiveness of the 16S rRNA gene in molecular diagnosis, and indicates a widespread prevalence of the virulence genes PVL and clfA in S.aureus isolates , reflecting the virulence of these isolates and their ability to cause severe infections , with the distribution of these genes influenced by environmental factors , sample type, and geographic location.