Abstract
Staphylococcus aureus has been identified as a major cause of nosocomial infections in hospitals. In this study, 41 S. aureus have been isolated from the nasal cavity of children in Libya. Congo red agar assay (CRA), semi quantitative adherence assay and microbial adhesion to solvent (MATS) test were used to study qualitative and quantitative biofilm formation of the isolated strains. Molecular detection of adhesion (icaA, icaD, fnbA, cna and clfA) genes was detected by polymerase chain reaction. Our results showed that 21 strains (51.2%) were slime producers on CRA plates. In a parallel way, 19 strains were slime producer on polystyrene plates. The MATS assay showed that all the studied strains have hydrophilic character. Molecular detection of adhesion genes revealed that 56.1% strains were icaA and icaD positives, 34.1% were cna positives, and 56.1% were fnbA positives. Moreover clfA gene was not detected in all the tested strains. This study confirms the adhesion ability and the presence of adhesion genes in the majority of the strains isolated from the nasal cavity of Libyan children.