Biofilm Formation and Prevalence of Biofilm-Related Genes Among Clinical Strains of Multidrug-Resistant

The biofilm-forming strains are responsible for causing a number of diseases. With the emergence of multidrug resistance they constitute a catastrophic threat to medicine. The ability of 65 clinical strains of multidrug-resistant (MDRSA) to form biofilm was examined in this study and analyzed in relation to SCC, type, microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), and genes. Results obtained from crystal violet and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays showed that all MDRSA strains tested form biofilm but, of 65 strains, only 18 strains (28%) were found to form a biofilm with high metabolic activity and a great amount of biomass. The high proportion of MDRSA isolates in our study made no significant difference for and MSCRAMMs genes according to biofilm-forming capacity, except for , , and gene. In addition, this study demonstrated that strains carrying SCC type I showed a significantly decreased biofilm viability compared with the strains harboring SCC type II and type IV, but SCC type could not serve as a good predictor of biofilm formation. However, we found that significantly weaker metabolic activity was detected in the biofilm of isolates with type t011.