Evaluation of virulence factors among Staphylococcus aureus strains isolated from patients with urinary tract infection in Al-Najaf Al-Ashraf teaching hospital

Staphylococcus aureus contains numerous surface proteins called microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) that mediate binding to host tissues and initiate colonization leading to infection. Virulence genes such as enzymes, toxins, adhesin proteins, cell surface proteins play an important role in the pathogenicity of S. aureus strains. The distribution and prevalence of virulence genes vary among S. aureus strains in different regions. However, the highest frequency of virulence genes among S. aureus strains is related to toxin genes. There are many PCR methods for detecting these microorganisms such as conventional PCR, multiplex PCR, reverse transcription PCR (RT-PCR), and quantitative PCR (qPCR). Therefore, this study aimed to investigate the presence of virulence genes among methicillin-resistant S. aureus (MRSA) strains. In this study, multiplex PCR technique was applied to determine the presence of virulence genes among MRSA strains. Results showed the frequency of virulence genes among bacterial strains isolated from Al-Najaf Al-Ashraf teaching hospital. In addition, among the strains, hla gene with ۹۱% frequency, exhibited the highest prevalence among pathogenic genes. Sea, mecA, clfB, femA, fnbB, tsst, hlb genes with ۸۸%, ۶۵%, ۵۴%, ۴۵%, ۳۹%, ۲۷% and ۱۳% were in the next ranks, respectively. This investigation showed mecA is a gene found in bacterial cells that allows them to be resistant to antibiotics such as methicillin and other penicillin-like antibiotics. 

Keywords:

multidrug-resistant bacteria , detection of virulence factors , toxins , adhesin proteins , cell surface proteins , adhesive matrix molecules