Association of different Candida species with catheter-related candidemia, and the potential antifungal treatments against their adhesion properties and biofilm-forming capabilities.

BACKGROUND

To compare the adhesion properties and biofilm-forming capabilities of 27 Candida isolates obtained from catheter-related candidemia patients and to evaluate the inhibitory effects of antifungal agents on different Candida species.

MATERIAL AND METHODS

Seven C. albicans, six C. parapsilosis, five C. guilliermondii, five C. tropicalis, and four C. glabrata clinical isolates were investigated. We quantified the adherence of these Candida species by flow cytometric method and evaluated the formation of biofilms by XTT reduction and crystal violet methods. Actions of micafungin (MF), fluconazole (FZ), and N-acetylcysteine (NAC) on the adhesion and biofilm formation of different Candida species were determined.

RESULTS

Non-albicans Candida species were demonstrated to have stronger adhesion abilities compared with C. albicans. The biofilm-forming capabilities of different Candida species were varied considerably, and the degree of biofilm formation might be affected by different assay approaches. Interestingly, C. parapsilosis displayed the highest biofilm formation abilities, while C. glabrata exhibited the lowest total biomass and metabolic activity. Furthermore, the inhibitory activities of MF, FZ, and NAC on fungal adhesion and biofilm formation were evaluated, and the results indicated that MF could reduce the adhesion ability and biofilm metabolism more significantly (p < 0.05), and its antifungal activity was elevated in a dose-dependent manner.

CONCLUSION

Non-albicans Candida species, especially C. guilliermondii, C. tropicalis, and C. parapsilosis, exhibited higher adhesion ability in catheter-related candidemia patients. However, these Candida species had varied biofilm-forming capabilities. MF tended to have stronger inhibitory effects against both adhesion and biofilm formation of different Candida species.