| Congresso Brasileiro de Microbiologia 2023 | Resumo: 947-1 | ||||
Resumo:Cryptococcus spp. is a clinically relevant yeast responsible for cryptococcosis, a systemic mycosis primarily affecting immunocompromised individuals, with high mortality rates. Certain virulence factors, such as the urease enzyme, play a crucial role in establishing infection and facilitating the fungus's spread, particularly to the central nervous system. Since urease is absent in humans, targeting this enzyme through inhibition presents an intriguing strategy for treating cryptococcal meningitis, especially when combined with conventional antifungals. To explore this approach, we tested synthetic molecules from new chemical classes to assess their potential in controlling fungal growth and inhibiting urease. A lead molecule (AF19) exhibited the most promising results among these compounds. We also tested a standard urease inhibitor (acetohydroxamic acid - AHA) for comparison. In our study, we employed Cryptococcus neoformans H99 strain to evaluate the minimum inhibitory concentration (MIC) against fungal growth and cell urease activity using the broth microdilution technique. Additionally, we determined the enzymatic inhibitory concentration of urease using a crude protein extract from a fungal culture. AF19 demonstrated remarkable inhibition of both fungal growth (MIC of 2-4 µg/mL) and cell urease activity (MIC of 0.5-1 µg/mL) in comparison to AHA, which displayed higher MIC values (128 µg/mL for fungal growth and 16-32 µg/mL for cell urease activity). Furthermore, our inhibitors displayed potent activity when directly tested on urease (crude protein extract). AF19 exhibited an impressively low inhibitory concentration (0.14 nM or 31.18 ng/mL), outperforming AHA (0.48 nM or 35.94 ng/mL). These findings highlight the significant potential of AF19 as a dual-action inhibitor of fungal growth and urease activity in Cryptococcus spp. This novel molecule may hold promise as a valuable addition to antifungal chemotherapy in combination with conventional antifungals. By targeting the crucial urease enzyme, AF19 offers a novel therapeutic avenue in the fight against cryptococcal infections. Palavras-chave: cryptococcosis, antifungal, urease inhibitors, virulence factor Agência de fomento:FAPESP, CNPq, FAPEMIG, CAPES | |||||