Fungal infectivities of implanted catheters due to Candida sp Biofilms formation and resistance

Background. - Candidemia are the most common fungal infections in hospitals. However, the catheters are subject to be altered by Candida biofilms which increase the risk of invasive nosocomial infections due to the high resistance to antifungal agents. Therefore, the minimum inhibitory concentrations of planktonic (MIC) and sessile cells (CIMS) were evaluated. Methods. - To review the in vivo biofilms structures of Candida sp. formed on the inner and/or external surfaces of collected catheters, we used scanning electron microscopy (SEM). The level of biofilm resistance was assessed against two conventional antifungal agents: amphotericin B (AmB), which belongs to the class of polyenes, and fluconazole (FLZ) which is an azole. Results. - The SEM observation of biofilms of Candida sp. reveals complex structures. Compared to MICs, the calculation of CIMS showed an increase of 32 times with AmB and of 128 times with FLZ. Conclusion. - Catheters offer an ideal surface to Candida sp. to form biofilms. This complex structure induces the increase of the resistance of sessile cells against two antifungal agents, AmB and FLZ. (C) 2015 Elsevier Masson SAS. All rights reserved.