In vitro susceptibility of amphotericin-B, voriconazole and caspofungin against Candida guilliermondii biofilms, isolated from dentals units water pipes, under different growth phases

Abstract

The dental units water pipes are a favorable medium for biofilms formation because of the small diameter of the pipe and the duration of water stagnation, but the question which arises is the nature of the biofilms which are formed inside? This article gives a progress report on the nature of this microbial contamination and precisely the fungal biofilms formation by examining their susceptibility to antifungal agents under different growth phases. Sixteen samples of dental units water pipes were taken from public dental clinic and from stomatology unit at the university hospital of Tlemcen (Algeria). The isolated strains were identified by the conventional mycological methods and were analyzed to determine their minimal concentrations inhibiting their growth (planktonic and sessile forms) using three antifungal agents. Five strains type Candida guilliermondii were identified and analyzed for their resistance to antifungal agents. Antifungal susceptibility testing demonstrated the sensitivity of all planktonic Candida guilliermondii cells against amphotericin-B, voriconzole and caspofungin but the sessile cells of these strains revealed a less susceptibility to antifungal agents and even a resistance when the biofilm made mature. Several types of yeast contaminated the dental units water pipes and especially Candida guilliermondii that was the most founded. This specie was susceptible to antifungal agents under planctonic forms and resistance where the biofilm made mature.