Avaliação da atividade antifúgica in vitro do sulfato de zinco isolado e associado ao fluconazol frente a Candida spp

Abstract

Fungal infections are becoming more and more frequent, especially in hospital settings. In this context, the fungal genus Candida spp. is characterized as an opportunistic genus responsible for high rates of morbidity and mortality. With the increasing use of antifungals and clinical resistance to them, a change in the epidemiology of Candida infections is taking place, highlighting the emergence of new therapeutic strategies. Therefore, the present study aimed to evaluate the in vitro antifungal activity of zinc sulfate, isolated and associated with fluconazole, against Candida spp. sensitive and resistant to fluconazole. The broth microdilution technique was used to determine the Minimum Inhibitory Concentration (MIC), according to the CLSI M27-A3 protocol, and the fluconazole resistance assessment was performed using the CLSI document M27-S4. In the analysis of the isolated effect of zinc sulfate, the interpretation of the antifungal effect was performed based on the MICs obtained. Regarding the evaluation of the association between zinc sulfate and fluconazole, the checkerboard technique was used, in which the pharmacological interaction between the drugs was determined according to the Fractional Inhibitory Concentration Index (CIIF). Zinc sulfate had a MIC that ranged from 16 to 64 µg/mL for the strains tested in the study, in which 100% of the strains had good antimicrobial activity. Regarding the combination of zinc sulfate with fluconazole, 62.5% of the interactions evaluated between zinc sulfate and fluconazole were classified as indifferent and 37.5% as additive for the analyzed strains. Considering the limited antifungal arsenal available, zinc sulfate stands out due to its in vitro antifungal activity. However, for its use, further studies are needed to make it a possible therapeutic alternative.