1-n-Hexadecyl-3-methylimidazolium methanesulfonate and chloride salts with effective activities against Candida tropicalis biofilms

Although the use of catheters in critically ill patients is mostly inevitable, this invasive procedure comes together with several health risks. Within this context, the contamination with Candida tropicalis is a primary concern as this highly prevalent pathogenic yeast can develop an extensive polymeric matrix that hinders the drugs' penetration and its effective treatment. This study addresses the potential for the 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C(16)MImMeS) and chloride (C(16)MImCl) salts for eliminating the viable cells of biofilms of Candida tropicalis, compared to the performance of chlorhexidine (CHX) and fluconazole (FLZ). The minimum concentration required of C(16)MImMeS, C(16)MImCl, CHX and FLZ for elimination of the biofilm0s viable cells (MBEC) was evaluated through microtitre plate biofilm exposure with different concentrations of these substances. These concentrations were determined at 80% of effective activity against the biofilm0s viable cells by using the MTT reduction assay. C(16)MImMeS and C(16)MImCl were able to eliminate the viable cells at much lower concentrations (15.6 and 0.45 mu g ml(-1) respectively) than CHX (1250 mu g ml(-1)) and FLZ (resistance of the viable cells). This demonstrates the high potential of these substances for nosocomial infections control.