title: Anti-metabolic activity of caspofungin against Candida albicans and Candida parapsilosis biofilms.
abstract: OBJECTIVE
  Candidiasis can be associated with the formation of biofilms on bioprosthetic surfaces and the intrinsic resistance of Candida albicans biofilms to the most commonly used antifungal agents has been demonstrated. In this study, we report on the antifungal activity of caspofungin at two different concentrations, on C. albicans and Candida parapsilosis biofilms with different ages of maturation.
  
  
  METHODS
  Fifteen strains of C. albicans (10 strains susceptible to fluconazole in vitro and five strains resistant to this antifungal agent) and six strains of C. parapsilosis (all were susceptible to fluconazole in vitro) were studied. The antifungal activity of caspofungin was assessed by looking for a significant inhibition of the metabolic activity of yeasts within biofilms. Biofilms of Candida were produced in vitro, on silicone catheters.
  
  
  RESULTS
  Caspofungin used at MIC did not modify the metabolic activity of C. albicans, whatever the maturation age of the biofilms. The same concentration of caspofungin significantly reduced the metabolism (P<or=0.001) of 25% (biofilms of 48 h) to 50% (biofilms of 2 h) of the C. parapsilosis yeasts. The use of a therapeutic concentration of caspofungin (2 mg/L) significantly decreased (P<or=0.001) the metabolism of all the strains of C. albicans and C. parapsilosis tested, independently of the biofilm maturation age. This potent antifungal activity of caspofungin on C. albicans biofilms was observed independently of the yeast susceptibility to fluconazole.
  
  
  CONCLUSIONS
  This study demonstrated that caspofungin used at MIC was not sufficient to reduce C. albicans biofilms, but it suggested an activity on C. parapsilosis biofilms depending on their maturation age. This study also indicated that caspofungin used at 2 mg/L could be a good candidate in the prevention of candidiasis associated with silicone medical devices. Our results also suggested that fluconazole resistance of yeasts did not affect caspofungin activity.
authors.affiliation: Laboratoire de Parasitologie et Mycologie Médicales, Centre Hospitalier Universitaire La Milétrie, BP 577, 86021 Poitiers Cedex, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Cocuaud
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Rodier
authors.forename: Gyslaine
authors.initials: G
authors.lastname: Daniault
authors.forename: Christine
authors.initials: C
authors.lastname: Imbert
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D000963:Antimetabolites / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002175:Candida / Q000187:drug effects* / Q000502:physiology; D002176:Candida albicans; D000077336:Caspofungin; D004305:Dose-Response Relationship, Drug; D026141:Drug Resistance, Multiple, Fungal; D054714:Echinocandins; D015725:Fluconazole / Q000494:pharmacology; D055666:Lipopeptides; D008826:Microbial Sensitivity Tests; D010456:Peptides, Cyclic / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D000963:Antimetabolites; D054714:Echinocandins; D055666:Lipopeptides; D010456:Peptides, Cyclic; D015725:Fluconazole; D000077336:Caspofungin