Aspirin as an Antifungal Lock Therapy Agent

Candida biofilms on central venous catheters are one of the commonest nosocomial fungal bloodstream infections. Antifungal lock solutions have been shown to be effective in salvaging indwelling catheters in patients requiring intravenous therapy. Objectives: To determine the activity of aspirin as a lock solution against four Candida biofilms on silicone catheter sections. Methods: Biofilms of Candida albicans, Candida glabrata, Candida krusei and Candida tropicalis were formed on silicone catheters in vitro. The catheters were exposed to lock therapy with aspirin at concentrations of 5 mg/ml – 45 mg/ml, for 2, 4 and 24 hr. Untreated biofilms served as controls. The catheters were then removed and quantified by culture and XTT assays. Results: Significant reduction in CFU counts (approaching 100%) was detected as early as 2 hr in C. albicans biofilms treated with 40 mg/ml aspirin, whereas the same level of reduction was only obtained at 45 mg/ml aspirin, locked for 4 hr in C. glabrata and C. tropicalis (p < 0.05). However, C. krusei only showed 50 % reduction of XTT activities at concentration of 45 mg/ml aspirin, locked for 24 hr. Conclusion: Our results showed that catheter-lock solution of aspirin may be used to salvage catheters infected with C. albicans, C. glabrata, C. tropicalis , but not C. krusei.