Correlation Between Biofilm-Formation and the Antibiotic Resistant Phenotype in Staphylococcus aureus Isolates: A Laboratory-Based Study in Hungary and a Review of the Literature

( ) is an important causative pathogen in human infections. The production of biofilms by bacteria is an important factor, leading to treatment failures. There has been significant interest in assessing the possible relationship between the multidrug-resistant (MDR) status and the biofilm-producer phenotype in bacteria. The aim of our present study was to assess the biofilm-production rates in clinical methicillin-susceptible [MSSA] and methicillin-resistant [MRSA] isolates from Hungarian hospitals and the correlation between resistance characteristics and their biofilm-forming capacity. A total of three hundred (n=300) isolates (corresponding to MSSA and MRSA isolates in equal measure) were included in this study. Identification of the isolates was carried out using the VITEK 2 ID/AST system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method and E-tests, confirmation of MRSA status was carried out using PBP2a agglutination assay. Biofilm-production was assessed using the crystal violet (CV) tube-adherence method and the Congo red agar (CRA) plate method. There were significant differences among MSSA and MRSA isolates regarding susceptibility-levels to commonly used antibiotics (in case of erythromycin, clindamycin and ciprofloxacin: p