Staphylococcus epidermidis virulence factor and ability of macroscopic biofilm production

Abstract

Introduction: Staphylococcus epidermidis is considered to be an important opportunistic pathogen. S.epidermidis ability to cause infection is due to its biofilm formation ability. Several bacterial molecules act as S. epidermidis adhesion objects and play role in bacterial adhesion to protein or polymeric surfaces. This study aimed to determine the correlation of virulence factors and macroscopic biofilm formation in S. epidermidis clinical isolates. Materials and Methods: A cross-sectional study was conducted including 59 S. epidermidis obtained from blood, urine, tracheal and wound samples in Tehran, Iran. S. epidermidis was identified by conventional bacteriological tests. Phenotypic biofilm formation assay was done by microtiter plate method. The virulence associated genes including icaA, IS256, aap, bhp and fbe were detected by specific PCR. Results: From 59 isolates 36 (61%) were able to produce macroscopic biofilm, of which 12(33.3%) were strong biofilm producers. Of the 36 biofilm producers, 32 (88.9%) were positive for icaA. The majority of the isolates carried fbe (91.7%), IS256 (77.8%), aap (72.2%), while bhp was presented only in (15.3%). Conclusion: This study demonstrated that the presence of virulence factors is correlated with macroscopic biofilm production. The presence of these virulence factors enables S. epidermidis to produce biofilm, colonize and survive in patients. In the case of immune system compromising or hospitalized patients, infections can occur and would be more complicated than the antibiotic resistance cases