title: Trichosporon inkin biofilms produce extracellular proteases and exhibit resistance to antifungals.
abstract: The aim of this study was to determine experimental conditions for in vitro biofilm formation of clinical isolates of Trichosporon inkin, an important opportunistic pathogen in immunocompromised patients. Biofilms were formed in microtitre plates in three different media (RPMI, Sabouraud and CLED), with inocula of 104, 105 or 106 cells ml- 1, at pH 5.5 and 7.0, and at 35 and 28 °C, under static and shaking conditions for 72 h. Growth kinetics of biofilms were evaluated at 6, 24, 48 and 72 h. Biofilm milieu analysis were assessed by counting viable cells and quantification of nucleic acids released into biofilm supernatants. Biofilms were also analysed for proteolytic activity and antifungal resistance against amphotericin B, caspofungin, fluconazole, itraconazole and voriconazole. Finally, ultrastructural characterization of biofilms formed in microtitre plates and catheter disks was performed by scanning electron microscopy. Greater biofilm formation was observed with a starter inoculum of 106 cells ml- 1, at pH 7.0 at 35 °C and 80 r.p.m., in both RPMI and Sabouraud media. Growth kinetics showed an increase in both viable cells and biomass with increasing incubation time, with maximum production at 48 h. Biofilms were able to disperse viable cells and nucleic acids into the supernatant throughout the developmental cycle. T. inkin biofilms produced more protease than planktonic cells and showed high tolerance to amphotericin B, caspofungin and azole derivatives. Mature biofilms were formed by different morphotypes, such as blastoconidia, arthroconidia and hyphae, in a strain-specific manner. The present article details the multicellular lifestyle of T. inkin and provides perspectives for further research.
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Rossana
authors: R
authors: de Aguiar Cordeiro
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Rosana
authors: R
authors: Serpa
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Camila
authors: C
authors: Flávia Uchoa Alexandre
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Francisca Jakelyne
authors: FJ
authors: de Farias Marques
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Charlline
authors: C
authors: Vladia Silva de Melo
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Jônatas
authors: J
authors: da Silva Franco
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Antonio
authors: A
authors: José de Jesus Evangelista
authors: Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil.
authors: Zoilo
authors: Z
authors: Pires de Camargo
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: Raimunda
authors: R
authors: Samia Nogueira Brilhante
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.|Post Graduate Program in Veterinary Sciences, State University of Ceará, Ceará, Brazil.
authors: Marcos
authors: M
authors: Fabio Gadelha Rocha
authors: Department of Pathology and Legal Medicine, Federal University of Ceará, Ceará, Brazil.
authors: José
authors: J
authors: Luciano Bezerra Moreira
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.|Christus College, School of Medicine, Fortaleza, Ceará, Brazil.
authors: Tereza
authors: T
authors: de Jesus Pinheiro Gomes Bandeira
authors: Medical Mycology Specialized Center, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors: José
authors: J
authors: Júlio Costa Sidrim
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D018441:Biofilms; D025141:Drug Resistance, Fungal; D005110:Extracellular Space / Q000201:enzymology* / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism*; D014250:Trichosporon / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; D010447:Peptide Hydrolases