Biochemical and molecular identifiction of staphylococcus aureus isolatles detection of PVL gene

This study aimed to identify the risk factors for wounds and burns patients in Iraq hospitals by antibiotic resistance of Staphylococcus aureus, and relate that virulence to their associated with PVL gene. 200 clinical samples were taken from patients with burns and wound infections at Al-Yarmuk General Education and Baghdad Medical City Hospital. As a result of their examination, Staphylococcus aureus was determined in 103 samples. While 50 samples were tested biochemically, the remaining 53 were identified using the VITEK2 system. Four antibiotics were used for antimicrobial susceptibility testing in the VITEK2 system. It was determined that the examined isolates were resistant to Cefoxitin (100 %), Benzylpenicillin (96.2 %), Oxacillin (94.3 %) and sensitive to Gentamicin (96.2 %), and all isolates were Methicillin-Resistant. Conventional PCR was performed for the molecular identification of S. aureus in 53 isolates for the detection of the 16S rRNA gene and the detection of the PVL virulence gene. As a result, 16S rRNA gene (100 %) and PVL gene (35.8 %) were visualized on agarose gel in tested isolates. Then, sequencing was applied to 12 bacterial isolates for the 16SrRNA gene and 5 bacterial isolates for the PVL gene, which gave positive results for two genes, and the alignment in the NCBI showed identities of 16SrRNA gene 99% and PVL gene 99% with global isolates of Staphylococcus aureus. Real-time PCR was applied for the detection of PVL genes in 53 isolates. The prevalence of the PVL gene was 41.5%. The fold gene expression of the PVL gene was 2.1 and the 16SrRNA was 0.8. In this study, it was concluded that the PVL virulence gene, which has a role in leukocyte lysis and tissue necrosis, has a higher prevalence in Methicillin-Resistant Staphylococcus aureus clinical isolates compared to previous studies and increases the virulence and pathogenicity of MRSA, as these MRSA had high multidrug resistance to the tested antibiotics.