Random Amplified Polymorphic DNA (RAPD)-PCR analysis of genotypic and phenotypic characteristics of MethicillinResistant <i>Staphylococcus epidermidis</i> (MRSE) strains involved in biofilm formation

Abstract

Purpose: The current study aims to investigate genotypic and phenotypic aspects of methicillinresistant Staphylococcus epidermidis (MRSE) strains involved in the biofilm formation and the attendance of the icaADB gene and genotypic characterization of this gene by random amplified polymorphic DNA (RAPD) PCR.Methods: 60 Staphylococcus epidermidis strains were isolated from clinical specimens, suspected of having the bacteria, from the laboratories of Isfahan. Biofilm formation was measured by the microtiter plate method. The attendance of biofilm formation genes was studied using PCR and all isolates producing biofilm (strong and moderate) were genetically classified by RAPD-PCR.Results: 37 isolates (61.7%) were MRSE and all positive biofilm strains. The prevalence of biofilmrelated genes in the isolates was SesC (100%), SesI (45.9%), icaA (29.7%), icaB (37.8%), icaC (81.08%), icaD (70.2%), arcA (81.08%), and opp3AB (70%). PCR analysis showed that among 30 isolates of strong and medium biofilm production, 70% (21/30) positive for the icaADB gene. The Dendrograms obtained from RAPD-PCR results showed that all nine main clusters were at an 80% similarity level, and there were four isolates of a single type.Conclusion: These findings confirmed the high genotypic diversity of biofilm-producing MRSE strains and the relative diffusion of specific clones among clinical samples.