Molecular Detection of Virulence Factors of Staphylococcus aureus and Their Relationship to Infection

Staphylococcus aureus is regarded as one of the most significant bacteria which infect human beings, causing various infections including simple skin infections, hospital-acquired infections, and severe systemic infections such as bacteremia. The pathogenicity of this bacterium is primarily attributed to its various virulence factors, such as adhesion factors, exotoxins and biofilm formation, which helps this bacterium to survive under different environmental conditions and evade the immune system of the host. The present study was designed to molecularly detect selected virulence genes of Staphylococcus aureus isolated from various clinical samples and the correlation of these virulence genes with the type of infection. Wounds samples were collected from patients, visiting the Kirkuk General Hospital in addition to blood samples and Urine samples. Culture methods and biochemical tests were used to identify the phenotype and then confirmed by Polymerase Chain Reaction (PCR) for the molecular confirmation. The nuc gene was selected as a diagnostic marker as well as virulence genes such as pvl and icaA. The results showed that the nuc gene was the most commonly found among the isolates, whereas the pvl gene was predominantly found in skin infections. Chronic and catheter-associated infections, however, had a higher prevalence of the icaA gene. In addition, the study identified multiple virulent strains containing more than one virulence factor, which could lead to more serious disease and hamper treatment. The study concluded that PCR is a rapid and accurate method for detecting virulence genes in Staphylococcus aureus, and its routine application in clinical laboratories could improve diagnosis and reduce complications associated with bacterial infections.