title: Candida tropicalis Biofilms: Biomass, Metabolic Activity and Secreted Aspartyl Proteinase Production.
abstract: According to epidemiological data, Candida tropicalis has been related to urinary tract infections and haematological malignancy. Several virulence factors seem to be responsible for C. tropicalis infections, for example: their ability to adhere and to form biofilms onto different indwelling medical devices; their capacity to adhere, invade and damage host human tissues due to enzymes production such as proteinases. The main aim of this work was to study the behaviour of C. tropicalis biofilms of different ages (24-120 h) formed in artificial urine (AU) and their ability to express aspartyl proteinase (SAPT) genes. The reference strain C. tropicalis ATCC 750 and two C. tropicalis isolates from urine were used. Biofilms were evaluated in terms of culturable cells by colony-forming units enumeration; total biofilm biomass was evaluated using the crystal violet staining method; metabolic activity was evaluated by XTT assay; and SAPT gene expression was determined by real-time PCR. All strains of C. tropicalis were able to form biofilms in AU, although with differences between strains. Candida tropicalis biofilms showed a decrease in terms of the number of culturable cells from 48 to 72 h. Generally, SAPT3 was highly expressed. C. tropicalis strains assayed were able to form biofilms in the presence of AU although in a strain- and time-dependent way, and SAPT genes are expressed during C. tropicalis biofilm formation.
authors.affiliation: CEB- Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.|Teaching and Research in Clinical Analysis Laboratory, Division of Medical Mycology, Universidade Estadual de Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil.
authors.forename: Melyssa
authors.initials: M
authors.lastname: Negri
authors.affiliation: CEB- Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal. soniasilva@deb.uminho.pt.
authors.forename: Sónia
authors.initials: S
authors.lastname: Silva
authors.affiliation: Teaching and Research in Clinical Analysis Laboratory, Division of Medical Mycology, Universidade Estadual de Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil.
authors.forename: Isis Regina Grenier
authors.initials: IR
authors.lastname: Capoci
authors.affiliation: CEB- Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Azeredo
authors.affiliation: CEB- Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Henriques
mesh_terms: D000199:Actins / Q000096:biosynthesis* / Q000235:genetics; D057055:Aspartic Acid Proteases / Q000096:biosynthesis* / Q000235:genetics; D018441:Biofilms / Q000254:growth & development*; D041022:Candida tropicalis / Q000254:growth & development* / Q000378:metabolism / Q000472:pathogenicity*; D002177:Candidiasis / Q000382:microbiology; D015169:Colony Count, Microbial; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D060888:Real-Time Polymerase Chain Reaction; D014556:Urine / Q000382:microbiology*; D037521:Virulence Factors
chemical_list: D000199:Actins; D005656:Fungal Proteins; D037521:Virulence Factors; D057055:Aspartic Acid Proteases
keywords: Artificial urine; Biofilm; Candida tropicalis; SAPT gene