Biofilm-forming ability and methicillin resistance among Staphylococci isolated from various surfaces in community settings

Abstract

Biofilm-forming ability and sensitivity to antibiotic methicillin of staphylococci outside the healthcare facilities is not sufficiently explored. The aim of this study was to examine the biofilm-forming capacity of staphylococci on various metal, plastic and leather surfaces in our living and working environment and the association between their biofilm production and methicillin resistance. Detection of methicillin resistance in staphylococci isolates were examined by cefoxitin disc diffusion test. Production of bacterial biofilms was investigated by two phenotypic methods: crystal violet (CV) tube-adherence method and Congo red agar (CRA) plate method. A total of 88 staphylococci isolates, 47 (53.41%) of S. aureus and 41 (46.59 %) of S. epidermidis strains were recovered from 100 collected samples. Among them, 35 methicillin-resistant strains (20 MRSA and 15 MRSE) were detected. Applying the CV tube adherence method, 21 (39.62%) MRSA and MRSE isolates were positive for biofilm production, while using the CRA method 15 (44.12%) MRSA and MRSE strains were detected as biofilm producers. Statistical analysis did not find association between biofilm production ability and methicillin resistance in both applied methods for a significance level of 0.05. The study shows that different objects and surfaces contaminated with biofilm-forming staphylococci, including MRSA and MRSE, may serve as environmental source of infection for long periods of time.