| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1010-1 | ||||
Resumo:Candida auris is a public health concern worldwide due to its persistence in hospital environments and resistance to multiple classes of antifungals. Together with the ability to form biofilms on different surfaces, these characteristics make it difficult to control infections, contributing to increased morbidity and mortality rates. In this context, the search for new molecules with antifungal activity is extremely important. Geraniol (GER), a component of essential oils from different plants, has antimicrobial properties against different microbial species. This study aimed to evaluate the antifungal activity of GER on adhesion and C. auris biofilms formed on polystyrene surface (96-well flat-bottom plate). C. auris CBS 10913 e C. auris CBS 12766 were used in this study. The GER stock solution was prepared with dimethyl sulfoxide and Tween 80, not exceeding 0.5% in the final concentration in the tests. Initially, the minimum inhibitory concentration (MIC) for planktonic cells was determined by the broth microdilution technique. For the adhesion assay, a suspension of 1.0x107 cells/well was incubated in the presence of GER in 0.15 M saline phosphate buffer (PBS), pH 7.2, and incubated at 37 °C, at 100 rpm, for 90 min. For assays on pre-formed biofilms, a final suspension of 1.0x106 cells/well was added to wells containing Roswell Park Memorial Institute 1640 medium with 3-[N-morpholino]propanesulfonic acid, and incubated at 37 °C for 4 h and 24 h. After incubation, the biofilms were washed with PBS and treated with GER for 24 h at 37 °C. In all assays, the viability of the cells was assessed by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) reduction method. The MIC of GER able to completely inhibit visual growth of both C. auris strains was 512 µg/mL. Based on this result, the effect of sub- and supra-MICs (128 to 1024 µg/mL) was analyzed on adhesion and pre-formed biofilms. In general, GER was able to inhibit adhesion and pre-formed C. auris biofilms. Considering 90% inhibition, increasing concentrations of GER were able to inhibit the different stages of the C. auris CBS 10913 biofilm. Thus, 128, 256 and 1024 µg/mL of GER inhibited adhesion, the biofilms formed for 4 and 24 h, respectively. Interestingly, 90% inhibition of adhesion of C. auris CBS 12766 to polystyrene was observed in the presence of 1024 µg/mL. However, biofilms formed for 4 and 24 h were inhibited (90%) at concentrations of 128 and 512 µg/mL, respectively. In conclusion, GER showed antifungal activity on planktonic and sessile cells of C. auris, indicating its potential for the development of new strategies to control infections by this fungus. Palavras-chave: antibiofilm, antifungal activity, natural product, polystyrene Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES-Finacial code 01). | |||||