In vitro efficacies of caspofungin or micafungin catheter lock solutions on Candida albicans biofilm growth.
OBJECTIVE
Caspofungin and micafungin belong to the echinocandins; the mechanism of action of echinocandins is based on the inhibition of (1,3)-beta-D-glucan synthase. The aim of this study was to investigate in vitro the optimal antifungal lock treatment details against a Candida albicans biofilm.


METHODS
An in vitro model of a C. albicans (ATCC 3153 or ATCC 66396) biofilm associated with 100% silicone catheters was used. The effectiveness of the antifungal treatment was assayed against biofilms aged 12 h or 5 days, after exposure to caspofungin (2 mg/L) or micafungin (5 mg/L) for 12 h. The durability of the reduction in the biofilm metabolic activity was investigated (1-3 days after echinocandin treatment). The efficacy of caspofungin and micafungin was determined by evaluating a significant decrease (P < 0.0001) in the metabolic activity of biofilm yeasts.


RESULTS
The results showed that the tested antifungal agents used as lock solution significantly (P < 0.0001) reduced the metabolic activity of C. albicans, whatever the biofilm maturation stage (12 h or 5 days old biofilms). The reduction in the metabolic activity of biofilm yeasts was maintained, even after 48 h.


CONCLUSIONS
These data suggest that caspofungin (2 mg/L) and micafungin (5 mg/L) could represent good candidates for the reduction or control of fungal biofilms associated with silicone medical devices, as part of an antifungal lock. They were able to induce a significant and persistent reduction in the yeast metabolic activity of intermediate and mature biofilms, 12 h and 5 days old, respectively, when used as catheter lock solutions.
Cateau
Estelle
E
Université de Poitiers, UMR CNRS 6008, Equipe de Microbiologie Fondamentale et Appliquée, 6 Rue de la Milètrie, BP 199, 86034 Poitiers Cedex, France. estelle.cateau@chu-poitiers.fr
Rodier
Marie-Hélène
MH
Imbert
Christine
C
D000935:Antifungal Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002176:Candida albicans / Q000187:drug effects* / Q000378:metabolism; D002177:Candidiasis / Q000517:prevention & control; D000077336:Caspofungin; D002404:Catheterization; D054714:Echinocandins / Q000494:pharmacology*; D004864:Equipment and Supplies / Q000382:microbiology*; D006801:Humans; D055666:Lipopeptides; D008074:Lipoproteins / Q000494:pharmacology*; D000077551:Micafungin; D012828:Silicones; D013997:Time Factors
D000935:Antifungal Agents; D054714:Echinocandins; D055666:Lipopeptides; D008074:Lipoproteins; D012828:Silicones; D000077336:Caspofungin; D000077551:Micafungin