Influence of antibiotics on biofilm formation by different clones of nosocomial Staphylococcus haemolyticus

is the most common organism among clinical isolatesof methicillin-resistant staphylococci. This study evaluated the ability to produce biofilm with the presence of the antibiotics (1/4 minimum inhibitory concentrations) of strains isolated from blood culture. Clonal distribution was assessed in pulsed-field gel electrophoresis. PCR assays were performed to detect , , , , , genes. strains grown in the presence of the antibiotics were investigated for biofilm formation on glass, polystyrene and catheter surfaces. Biofilm formation was independent of the presence of the and genes, pulsed-field gel electrophoresis type. Vancomycin, oxacillin, moxifloxacin, rifampicin, teicoplanin, tigecycline and linezolid did not inhibit biofilm formation on abiotic surfaces. This study demonstrated that the biofilm formation process is complex and may not be related to gene carriage. Furthermore, in this study the biofilm formation was increased in the presence of antimicrobial agents.