Antifungal susceptibility of Sporothrix schenckii complex biofilms. (8th June 2017)

• Record Type: Journal Article
• Authors: Brilhante, Raimunda Sâmia Nogueira; de Aguiar, Felipe Rodrigues Magalhães; da Silva, Maria Lucilene Queiroz; de Oliveira, Jonathas Sales; de Camargo, Zoilo Pires; Rodrigues, Anderson Messias; Pereira, Vandbergue Santos; Serpa, Rosana; Castelo-Branco, Débora de Souza Collares Maia; Correia, Edmilson Emanuel Monteiro; Pereira-Neto, Waldemiro Aquino; Cordeiro, Rossana de Aguiar; Rocha, Marcos Fábio Gadelha; Sidrim, José Júlio Costa
• Is Part Of: Medical mycology. Volume 56:Number 3(2018)
• Page Start: 297
• Page End: 306
• Publication Date: 2017-06-08
• Subjects: Sporothrix -- biofilm -- antifungal susceptibility -- antimicrobial resistance; Medical mycology -- Periodicals; Veterinary mycology -- Periodicals; Mycology -- Periodicals; Mycoses -- Periodicals; Pathogenic fungi -- Periodicals; 616.969005
• DOI: 10.1093/mmy/myx043
• Languages: English
• ISSNs: 1369-3786

Abstract

Abstract: Sporotrichosis, caused by species of Sporothrix schenckii complex, is the most prevalent subcutaneous mycosis in many areas of Latin America. The aim of this study was to evaluate the ability of Sporothrix spp. to form biofilms in vitro and to characterize the growth kinetics, morphology, and antifungal susceptibility of biofilms against classical antifungals. We investigated the ability of strains to produce biofilms in vitro and determined the effects of exposure to amphotericin B, itraconazole, caspofungin, ketoconazole, voriconazole, and fluconazole at minimum inhibitory concentration (MIC) against planktonic form and at 10× MIC and 50× MIC on the biomass and metabolic activity of these biofilms. Biofilm structure was analyzed by optical microscopy using Congo-red staining, confocal and scanning electron microscopy. Strains were classified for biofilm-forming ability, through the analysis of absorbance of crystal violet retained by biomass of mature biofilms. We found that all S. brasiliensis ( n = 10), S. schenckii sensu stricto ( n = 2), S. globosa ( n = 2), and S. mexicana ( n = 4) strains were strong biofilm-producers. The analyzed biofilms had dense network of hyphae and conidia immersed in extracellular matrix, with presence of water channels. Antifungal drugs at the three tested concentrations showed different effects on biomass and metabolic activity of biofilms. However, the best inhibitory response was observed with 50× MIC of amphotericin B and caspofungin, which reduced these parameters. Furthermore, high drug concentrations, especially amphotericin B and caspofungin, showed antifungal activity against these biofilms, probably because they damaged the architecture and extracellular matrix, allowing diffusion of the drugs.