Influence of sub-inhibitory concentrations of antimicrobial agents on biofilm formation in indwelling medical devices

Abstract

Biofilms of Staphyloccocus epidermidis and Candida spp. are two of the most frequent factors of infection and pathogenesis associated to the use of indwelling medical devices. Several strategies have been proposed and/or developed to prevent infection. The aim of this study was to compare the effect of sub-inhibitory concentrations of anti-microbial agents on biofilm formation. Biofilms of three strains of S. epidermidis and two of both Candida albicans and Candida dubliniensis where formed in the presence of three antibiotics and two antifungal agents respectively. Based in the control samples, the percentage of biofilm formation inhibition by the different agents was determined and compared. The results showed that the influence of the antibacterial and antifungal agents tested is strain dependent, with the effect of the different agents also varying among strains, even if they have the same mechanism of action.