An investigation of genes coding fibronectin binding proteins in Staphylococcus aureus isolated from carriers aged between 6 and 14 years

Aim: Nasal carriage rates for Staphylococcus aureus have been reported to vary between 18% and 50% in different populations and it represents a risk factor for invasive infections. The aim of the present study was to investigate the presence of genes associated with fibronectin binding proteins mediating the adhesion of S. aureus to human epithelial cells.Materials and methods: Fifty strains isolated from nasal swab specimens of children were included. Specimens were inoculated on mannitol salt agar plates and after 24-48 h of incubation at 37 °C the isolates were identified according to their biochemical properties. The presence of fnbA and fnbB genes encoding fibronectin binding protein A and B was investigated via PCR. S. aureus NCTC8325 was used as the reference strain.Results: All isolates were identified as S. aureus according to their cultural properties and the positive tube coagulase test results. Of the 50 S. aureus strains, 14 (28%) were positive for fnbA and 5 (10%) for fnbB.Conclusion: The presence of fnbA and fnbB in our study population was lower than in previous studies performed in nasal carriers. We concluded that this difference might have resulted from the lower age of the study population and geographical diversities.