Débora Alves Nunes Mario1, Roberto Christ Vianna Santos2, Laura Bedin Denardi3, Rodrigo de Almeida Vaucher2, Janio Morais Santurio3, Sydney Hartz Alves3. 1. Departamento de Microbiologia e Parasitologia, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil; Faculdade Meridional Imed, Passo Fundo, Rio Grande do Sul, Brazil. Electronic address: debora_alves6@hotmail.com. 2. Laboratório de Microbiologia Clínica, Centro Universitário Franciscano, Santa Maria, Rio Grande do Sul, Brazil. 3. Departamento de Microbiologia e Parasitologia, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
Abstract
BACKGROUND: The presence of melanin in the fungal cell is a major virulence factor of the genus Sporothrix since it protects the fungal cells against the defense systems. AIMS: The present study aimed to investigate the interference of melanin in the susceptibility of Sporothrix brasiliensis and Sporothrix schenckii sensu stricto to amphotericin B and itraconazole, drugs recommended as therapy for disseminated and subcutaneous sporotrichosis, respectively. METHODS: Yeast cells were cultivated in minimal medium with or without l-DOPA in order to induce the production of melanin. Microdilution and killing assay methods were used to determine the antifungal activity against yeast cells with different amounts of melanin. RESULTS: The killing assay showed that melanization protected isolates within the S. schenckii complex from amphotericin B, particularly in the lower concentrations tested. CONCLUSIONS: Studies combining amphotericin B and inhibitors of melanin are required in order to avoid this effect.
BACKGROUND: The presence of melanin in the fungal cell is a major virulence factor of the genus Sporothrix since it protects the fungal cells against the defense systems. AIMS: The present study aimed to investigate the interference of melanin in the susceptibility of Sporothrix brasiliensis and Sporothrix schenckii sensu stricto to amphotericin B and itraconazole, drugs recommended as therapy for disseminated and subcutaneous sporotrichosis, respectively. METHODS:Yeast cells were cultivated in minimal medium with or without l-DOPA in order to induce the production of melanin. Microdilution and killing assay methods were used to determine the antifungal activity against yeast cells with different amounts of melanin. RESULTS: The killing assay showed that melanization protected isolates within the S. schenckii complex from amphotericin B, particularly in the lower concentrations tested. CONCLUSIONS: Studies combining amphotericin B and inhibitors of melanin are required in order to avoid this effect.
Authors: Laura C García-Carnero; Héctor M Mora-Montes; Nallely Nava-Pérez; Lisset G Neri-García; Oscar E Romero-González; Joshua A Terrones-Cruz Journal: Infect Drug Resist Date: 2022-04-22 Impact factor: 4.177
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