BACKGROUND: Trichosporon asahii is a yeast-like fungus that has recently gained importance as a cause of opportunistic systemic infections. The pathogenicity and virulence factors of T. asahii remain largely unknown. Because of the association between invasive infections and the use of catheters and related devices, the ability of the microorganism to adhere and form biofilms may play an important role in the pathogenicity during a trichosporonosis. AIMS: The aim of this study is to identify an association between biofilm formation by T. asahii isolates and their genotype and/or clinical source. METHODS: The biofilm production of 49 T. asahii strains isolated from Mexican patients was measured using the crystal violet stain method, and a comparison made with different adhesion phase incubation times. Antifungal susceptibility testing was performed using a modified CLSI protocol coupled with the quantification of the viable cells with the XTT reduction method. RESULTS: All the T. asahii isolates assayed were able to produce biofilm in vitro, with an intraspecific variability being observed. Overall, increased biofilm production was found when extending the adhesion phase incubation time from 2 to 4h. No association could be established between the biofilm-producing phenotype and either the genotype or clinical source. Higher antifungal resistance to amphotericin B and fluconazole was linked to increased biofilm production by T. asahii. CONCLUSIONS: All clinical isolates tested were able to produce biofilm. No association could be established between biofilm formation and genotype or clinical source.
BACKGROUND:Trichosporon asahii is a yeast-like fungus that has recently gained importance as a cause of opportunistic systemic infections. The pathogenicity and virulence factors of T. asahii remain largely unknown. Because of the association between invasive infections and the use of catheters and related devices, the ability of the microorganism to adhere and form biofilms may play an important role in the pathogenicity during a trichosporonosis. AIMS: The aim of this study is to identify an association between biofilm formation by T. asahii isolates and their genotype and/or clinical source. METHODS: The biofilm production of 49 T. asahii strains isolated from Mexican patients was measured using the crystal violet stain method, and a comparison made with different adhesion phase incubation times. Antifungal susceptibility testing was performed using a modified CLSI protocol coupled with the quantification of the viable cells with the XTT reduction method. RESULTS: All the T. asahii isolates assayed were able to produce biofilm in vitro, with an intraspecific variability being observed. Overall, increased biofilm production was found when extending the adhesion phase incubation time from 2 to 4h. No association could be established between the biofilm-producing phenotype and either the genotype or clinical source. Higher antifungal resistance to amphotericin B and fluconazole was linked to increased biofilm production by T. asahii. CONCLUSIONS: All clinical isolates tested were able to produce biofilm. No association could be established between biofilm formation and genotype or clinical source.
Authors: Rossana de Aguiar Cordeiro; Ana Luiza Ribeiro Aguiar; Bruno Nascimento da Silva; Lívia Maria Galdino Pereira; Fernando Victor Monteiro Portela; Zoilo Pires de Camargo; Reginaldo Gonçalves de Lima-Neto; Débora de Souza Collares Maia Castelo-Branco; Marcos Fábio Gadelha Rocha; José Júlio Costa Sidrim Journal: Front Cell Infect Microbiol Date: 2021-04-22 Impact factor: 5.293