Molecular Characterization of Exotoxin Genes in Staphylococcus aureus Recovered From Hospitalized Patients

Background: Staphylococcus aureus is considered as a major cause of skin and soft tissue infections, arthritis, osteomyelitis, infective endocarditis, and pneumoniae though community or nosocomial transmission. In this study, attempts were made to investigate the distribution of some important exotoxin genes, including hla, hlb, tsst-1, eta, etb, and etd among methicillin-resistant S. aureus (MRSA) isolated from a hospital patients in Tabriz, Iran. Methods: In the present cross-sectional study, a total of 90 S. aureus were isolated from children who admitted to a hospital during six-month in 2017. Isolates were identified using biochemical tests and then, using PCR, the isolates were tested for the presence of, hla, hlb, tsst-1, eta, etb, and etd genes. Results: It was found that 40% of the S. aureus were considered as MRSA strains by biochemical and molecular tests. The results of molecular detection of virulence determinants showed that eta, hla, etb, tsst-1, hlb and etd were detected in 86.1%, 80.5%, 30.5%, 27.7%, 22.2%, and 19.4% of isolates, respectively. Conclusion: Our findings clarify characterization of toxin production status of S. aureus isolates from patients in Iran. The current study showed that a majority of S. aureus isolates harbored eta and hla virulence gene.