The biofilm formation properties of the S. epidermidis isolates obtained from conjunctiva and multi-drug resistance

Abstract

Objective: Biofilm was shown on ocular abiotic surfaces such as contact lenses, intra-ocular lenses, glaucoma shunts and corneal sutures. The aim of this study is to compare success of Microtiter plate (MTP) and Congo Red Agar (CRA) methods in showing biofilm formation of S.epidermidis isolates that were obtained from conjunctiva regarding presence of icaA gene locus and multi-drug resistance.Design: InterventionalSetting: Department of Biology, Faculty of Science, Eskisehir Technical UniversitySubjects: S. epidermidis isolates obtained from conjunctivas of healthy patientsInterventions: MTP and CRA methods and antibiotic susceptibility tests were done and scanning electron microscopy was performed. Main outcome measures: Biofilm forming capacity, multidrug resistance states and bacterial adhesion of S. epidermidisResults: Nine isolates were found as strong biofilm producers with MTP and CRA methods. There were six icaA negative isolates, one of which was not a biofilm producer. From the icaA and icaD positive isolates, 13 were biofilm negative with MTP method and seven were biofilm negative with CRA method. Eighteen isolates were determined as resistant to three or more antibiotics. Ten of 18 isolates were strong biofilm producer with MTP and eight of 18 isolates were strong biofilm producer with CRA. Biofilm producer isolates were found to be resistant to antibiotics.Conclusion: It is noted that biofilm formation capacity of S. epidermidis isolates that were obtained from ocular surface were determined and multidrug resistance were estimated more successfully with MTP method. However, there is no method which can successfully detect biofilm formation capacity with 100% accuracy.