Vigilância em saúde única da resistência a antifúngicos e a compostos de amônio quaternário em Candida spp. no Ceará e busca por alternativa terapêutica

Abstract

From a One Health perspective, tackling antifungal resistance in Candida spp. requires an understanding of multiple factors, such as interaction with environments and chemical agents. Furthermore, drug repositioning and combination therapy are strategies to overcome therapeutic failures. This study aimed to isolate and identify Candida spp. from human clinical samples (n=59), hospital surfaces (n=25), production animals (n=107), and the environment of these animals (n=9); analyze the sensitivity profile to the antifungals FLC, MCF, and AMB; and the effect of benzalkonium chloride (BZ) and didecyl dimethyl ammonium chloride (DDAC) against isolates in planktonic and biofilm forms, as well as evaluate the effect of deferiprone (DEF), an iron chelator, on Candida spp. in planktonic and biofilm forms, isolated and in combination with the antifungals fluconazole (FLC), amphotericin B (AMB), and caspofungin (CAS). Finally, it was evaluated whether the inhibition of the fungus by DFP was reversed with ferrous sulfate (FeSO₄). Sensitivity to antifungals, quaternary ammonium compounds, and deferiprone was analyzed according to document m27-a3. The checkerboard method was used to evaluate the interaction between deferiprone and the antifungals. The antibiofilm activity of the antifungals, ammonium compounds, and deferiprone was evaluated by MTT reduction and biomass quantification by crystal violet. 109 Candida spp. yeasts were isolated. FLC showed variable MIC, from 0.125 to 64 µg/ml for isolates of human origin; 0.5 to 4 µg/ml for isolates from hospital environments; 0.125 to 64 µg/ml for isolates of animal origin, and 1 to 32 µg/ml for isolates from animal environments. MICs for MCF ranged from 0.0625 to 0.5 µg/ml for isolates of human origin; 0.0625 to 1 µg/ml for isolates from hospital environments; 0.0625 to 0.1 µg/ml for isolates of animal origin, and 0.03 µg/ml for isolates from animal environments. AMB exhibited MICs of 0.031 to 1 µg/ml for isolates of human origin; 0.125 to 0.5 µg/ml for isolates from hospital environments; 0.031 to 1 µg/ml for isolates of animal origin, and 0.06 and 0.25 µg/ml for isolates from animal environments. DDA showed MICs between 0.0625 and 1 µg/mL, and BZ showed MICs ranging from 0.0625–4 µg/mL. Forming and mature Candida spp. biofilms showed a significant reduction in metabolic activity and biomass after exposure to BZ and DDA. DEF showed MICs ranging from 16 to 1024 µg/mL against the tested isolates. In the checkerboard assay, DEF reduced the MICs of FLC, AMB, and CAS by up to 8, 32, and 64 times, respectively, against the planktonic form. In the MTT assay, DEF caused an increase in the metabolic activity of forming biofilms of C. tropicalis and C. glabrata; and a tendency towards reduced metabolic activity of mature Candida spp. biofilms (n=12) at 1024 µg/mL. Crystal violet analysis revealed an increase in the biomass of forming C. parapsilosis biofilms when treated with DEF; and a tendency towards a reduction in mature Candida spp. biofilms (n=12) at concentrations of 256 to 1024 µg/mL and 2 to 32 µg/mL, when compared to drug-free controls. Supplementation with (FeSO₄) reduced the antifungal efficacy of DEF against planktonic Candida spp. DEF demonstrated antifungal activity and synergism with FLC, AMB, and CAS against Candida spp., with greater efficacy observed against C. glabrata. Furthermore, DEF significantly influenced biofilm formation, showing a species-dependent effect. However, its effectiveness was significantly reduced by supplementation with FeSO₄, demonstrating that it acts directly on iron balance for Candida spp.