Biofi lm formation by Candida albicans isolated from intrauterine devices

摘要

Our survey revealed that infected intrauterine devices (IUDs) recovered from patients suffering from reproductive tract infections (RTIs) were tainted with Candida biofi lm composed of a single or multiple species. Scanning electron microscopy (SEM) analysis of C. albicans biofi lm topography showed that it consists of a dense network of mono- or multilayer of cells embedded within the matrix of extracellular polymeric substances (EPS). Confocal scanning laser microscopy (CSLM) and atomic force microscopy (AFM) images depicted that C. albicans biofi lms have a highly heterogeneous architecture composed of cellular and noncellular elements with EPS distributed in the cell–surface periphery or at cell–cell interface. Biochemical analysis showed that EPS produced by C. albicans biofi lm contained signifi cantly reduced total carbohydrate (40%), protein (5%) and enhanced amount of hexosamine (4%) in contrast to its planktonic counterparts. The in vitro activity of antifungal agents amphotericin B, nystatin, fl uconazole and chlorhexidine against pre-formed C. albicans biofi lm, assessed using XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]- 2H-tetrazolium-5-carboxanilide) reduction assay revealed increased resistance of these infectious biofi lm (50% reduction in metabolic activity at a concentration of 8, 16, 64, 128 μg/ml respectively) in comparison to its planktonic form.