Background and objectives: Staphylococcus aureus (S. aureus) is common hospital acquired pathogen. Biofilm formation capacity of S. aureus increases its pathogenicity. Biofilm formation is controlled by several factors among which are intracellular adhesion genes (ica) and fibronectin binding protein Genes (FnB). The aim of the present study is to evaluate the genotypic and phenotypic capacity of clinically isolated S. aureus strains for formation of biofilms.
Materials and methods: The study was conducted on 182 consecutive S. aureus isolates obtained from patients with hospital acquired infections. The isolates were subjected to antibiotics study by disc diffusion method, biofilm detection by microtitre plate method. Molecular studies for icaR, icaA, icaB, icaD and FnbA and FnbB was carried out by polymerase chain reaction.
Results: The frequency of biofilm formation among S. aureus was 35.5%. The most frequent detected genes among S. aureus were icaR (68.2%), icaC (63.6%), ica D (60.6%), fibA 56.1%, fib (53.0%, icaB, 51.5% and icaA 30.3%. Twenty one isolates of S. aureus had no detected genes of the studied seven genes.
Conclusion: The present study reveals that biofilm formation was common our clinical isolates of S. aureus. The prevalence of icaABCDR genes and fib A, B were common among these isolates with predominance of icaR gene. Biofilm formation was associated with significant antibiotics resistance. Longitudinal studies are required to evaluate biofilm formation and its genetic mechanisms.