title: Interference of melanin in the susceptibility profile of Sporothrix species to amphotericin B.
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.
  
  
  OBJECTIVE
  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.affiliation: 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.
authors.forename: Débora Alves Nunes
authors.initials: DA
authors.lastname: Mario
authors.affiliation: Laboratório de Microbiologia Clínica, Centro Universitário Franciscano, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Roberto Christ Vianna
authors.initials: RC
authors.lastname: Santos
authors.affiliation: Departamento de Microbiologia e Parasitologia, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Laura Bedin
authors.initials: LB
authors.lastname: Denardi
authors.affiliation: Laboratório de Microbiologia Clínica, Centro Universitário Franciscano, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Rodrigo de Almeida
authors.initials: Rde A
authors.lastname: Vaucher
authors.affiliation: Departamento de Microbiologia e Parasitologia, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Janio Morais
authors.initials: JM
authors.lastname: Santurio
authors.affiliation: Departamento de Microbiologia e Parasitologia, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Sydney Hartz
authors.initials: SH
authors.lastname: Alves
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D017964:Itraconazole / Q000494:pharmacology*; D008543:Melanins / Q000502:physiology*; D008826:Microbial Sensitivity Tests; D013175:Sporothrix / Q000187:drug effects*
chemical_list: D000935:Antifungal Agents; D008543:Melanins; D017964:Itraconazole; D000666:Amphotericin B
keywords: Amphotericin B; Anfotericina B; Melanin; Melanina; Resistance; Resistencia; Sensibilidad; Sporothrix; Susceptibility