| Congresso Brasileiro de Microbiologia 2023 | Resumo: 558-1 | ||||
Resumo:The epidemiological scenario of infections caused by Candida spp. got worse in recent years due to the increase of antifungal resistance. In recent decades, there has been an emphasis on the rise of Candida non-Candida albicans species, in which Candida tropicalis is protagonist. Furthermore, since 2009, there has been a new major global concern about the emergence of the multidrug-resistant species Candida auris. For both, there is something in common: growing epidemiology and resistance combined with scarce pharmacology. The present work aims to explore the repurposing of drugs, addressing miltefosine (MFS) in the synergistic effect with amphotericin B (AmB) and in antivirulence effect to C. tropicalis and C. auris. For this, 4 strains of C. auris (CBS 10913, CBS 12766, B11221 and B11244) and 6 strains of C. tropicalis (ATCC 200956, IAL 1, IAL 4, IAL 8, 49.07 and 335.07) were used. In the beginning, broth microdilution and checkerboard assays were performed to raise the susceptibility profile and synergism between these drugs, respectively. The effect of MFS on biofilm formation (1.5h) and preformed biofilm (24h) was measured by metabolic activity (XTT), total biomass (Crystal Violet) and cell viability (FUN-1) for both species. Additionally, for C. tropicalis (true hyphae former), the inhibition of filamentation by MFS in different culture media (RPMI-1640, Lee's Glucose, Spider and N-acetylglucosamine) was analyzed. In C. tropicalis, strains ATCC200956, IAL 4 and IAL 8 were resistant to fluconazole (FLC) and susceptible to AmB. The others (IAL 01, 49.07 and 335.07) were susceptible to FLC and AmB. For C. auris, only CBS 10913 strain was susceptible to FLC, while the other 3 strains have a pan-azole resistance profile and all were susceptible to AmB. When tested with MFS, the 10 isolates showed a minimum inhibitory concentration (MIC) at 1-4 µg/mL. Added to this, AmB and MFS showed synergistic activity against 10 isolates (Fractional Inhibitory Concentration Index - FICI: 0.13-0.5). MFS inhibited the biofilm formation (2-8 µg/mL) and the preformed biofilm (32-128 µg/mL) both metabolic activity and total biomass. Data on total biomass and biofilm viability confirm that the cells are not viable, despite the presence of cellular material. As for C. tropicalis filamentation, it was possible to observe a total inhibition by the subinhibitory concentration of MFS (2 µg/mL). It is important to highlighted that the MFS action profile is independent of the species and the previous susceptibility/resistance of the isolates to other antifungal classes. Furthermore, the synergism with AmB, already seen in C. auris, was reaffirmed and expanded for C. tropicalis. The action of MFS on filamentation of C. tropicalis and on biofilms of C. tropicalis and C. auris reinforces the importance of MFS in antivirulence effects by being able to inhibit the biofilms of Candida spp. and the hyphae formation, the main form of tissue invasion. Thus, the data presented guide further studies on the effect of MFS and its possible activity on other virulence factors of the species, as well as stimulating the search for more molecules with antifungal effects. Palavras-chave: Candidemia, virulence factors, miltefosine, drug repurposing Agência de fomento:Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, 2021/01279-5 e 2022/08516-5) e Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, 88887.663125/2022-00) | |||||