Composto com ligante de guanidina atua na cinética de crescimento de Candida albicans

Abstract

The oral cavity harbors a diverse microbiota, including the yeast Candida albicans, which is usually commensal but can become pathogenic, causing oral candidiasis in immunocompromised individuals or under conditions of imbalance. This condition affects the oral mucosa with white or reddish lesions. Current treatment options include chlorhexidine, a broad-spectrum antiseptic commonly used to manage bacterial and fungal infections. Although chlorhexidine is effective in preventing microbial growth, it has limitations such as oral irritation and dental discoloration. Furthermore, the increasing prevalence of fungal infections highlights the urgent need for alternative therapies. In this context, guanidine, a stable organic compound with antifungal activity, has attracted attention. Compounds with guanidine ligands stand out due to their ability to interact with molecular targets and their potential to combat infections. This study aimed to investigate the antifungal potential of a guanidine-ligand compound against C. albicans (ATCC 90028) and an oral isolate. The broth microdilution method was used to determine the Minimum Inhibitory Concentration (MIC), evaluating concentrations of the guanidine-ligand compound (AUD 1-98) ranging from 0.39 to 50 µg/mL against C. albicans (ATCC 90028) and the oral isolate (ISO 03), and determining the MIC and Minimum Fungicidal Concentration (MFC). To assess kinetic growth at intervals of 0, 4, 8, 12, 24, 28, 32, 36, 44, and 48 hours, the compound AUD 1-98 was analyzed at MIC and 2xMIC concentrations, and chlorhexidine was tested at its MIC concentration. The results showed that AUD 1-98 presented MIC and MFC values of 50 µg/mL for both C. albicans and the oral isolate. Regarding kinetic growth, AUD 1-98 demonstrated fungicidal activity against both microorganisms at MIC and 2xMIC concentrations (with a reduction of <3 log10) and achieved a 100% reduction in Colony-Forming Unit (CFU)/mL counts. In conclusion, the guanidine-ligand compound demonstrated fungicidal activity against C. albicans and the oral isolate, emerging as a promising candidate for the development of new antifungal agents. However, further studies are necessary to investigate its mechanisms of action and pharmacological safety profile.