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In vitro anti-biofilm activity of micafungin in a lock strategy

Abstract number: P701

Cateau E., Rodier M-H., Berjeaud J-M., Imbert C.

Objectives: Catheter-related candidiasis are associated with the formation of a fungal biofilm which alters the susceptibility to antifungal agents. Catheter lock therapy could represent a conservative strategy of the catheter in candidaemia involving the static instillation, usually during 12h, of a concentrated solution of antimicrobial agent (100 to 1000 MIC) into the catheter lumen. This study deals with the in vitro anti-biofilm potential of micafungin, used as a lock solution, to manage C. albicans biofilms.

Methods: Biofilms of two C. albicans strains (ATCC 66396 and ATCC 3153), 12 hours or 5 days old, were formed on 0.5 cm sections of 100% silicone catheters. Micafungin 5 mg/mL (corresponding approximately to 170 MIC) was then added to the biofilms and catheters were incubated for 12h at 37°C. Micafungin was then removed by washing. The metabolic activity of yeasts within the biofilm was assessed with XTT method, 24h, 48h or 72h after the end of the locks. Controls without antifungal were realised and used as references to calculate the inhibition percentages induced by micafungin locks.

Results: For a young C. albicans biofilm (12h), the growth inhibition induced by a 12h micafungin 5 mg/mL lock therapy and observed after a 24h culture without antifungal was at least 67% whatever the studied strain. 48h after the end of the lock, micafungin demonstrated a significant inhibitory activity on the development of 12h old biofilms, reaching at least 54%. 72h after the end of the lock, the inhibition observed was at least 40%.

The efficiency of micafungin lock on the development of a mature C. albicans biofilm (5 days old) was also significant: the inhibition observed 24h or 48h after the end of the lock was at least 54% suggesting a persistent efficiency.

Conclusion: These results showed that the micafungin lock treatment was efficient in vitro, on the studied strains, whatever the biofilm maturation stage. This study suggests that this echinocandin could have a real anti-biofilm potential and could become an interesting actor in the lock approach.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Barcelona, Spain
Presentation type:
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