title: Characterization of Paracoccidioides brasiliensis by FT-IR spectroscopy and nanotechnology.
abstract: Paracoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis, is a dimorphic fungus existing as mycelia in the environment (or at 25°C in vitro) and as yeast cells in the human host (or at 37°C in vitro). Because mycological examination of lesions in patients frequently is unable to show the presence of the fungus and serological tests can misdiagnose the disease with other mycosis, the development of new approach's for molecular identification of P. brasiliensis spurges is needed. This study describes the use of a gold nanoprobe of a known gene sequence of P. brasiliensis as a molecular tool to identify P. brasiliensis by regular polymerase chain reaction (PCR) associated with a colorimetric methods. This approach is suitable for testing in remote areas because it does not require any further step than gene amplification, being safer and cheaper than electrophoresis methods. The proposed test showed a color change of the PCR reaction mixture from red to blue in negative samples, whereas the solution remains red in positive samples. We also performed a Fourier Transform Infrared (FT-IR) Spectroscopy analysis to characterize and compare the chemical composition between yeast and mycelia forms, which revealed biochemical differences between these two forms. The analysis of the spectra showed that differences were distributed in chemical bonds of proteins, lipids and carbohydrates. The most prominent difference between both forms was vibration modes related to 1,3-β-glucan usually found in mycelia and 1,3-α-glucan found in yeasts and also chitin forms. In this work, we introduce FT-IR as a new method suitable to reveal overall differences that biochemically distinguish each form of P. brasiliensis that could be additionally used to discriminate biochemical differences among a single form under distinct environmental conditions.
authors.affiliation: Institute of Research and Development, Universidade do Vale do Paraíba, Univap, Avenida Shishima Hifumi, 2911, Urbanova, 12244-000 São José dos Campos, SP, Brazil.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ferreira
authors.affiliation: Institute of Research and Development, Universidade do Vale do Paraíba, Univap, Avenida Shishima Hifumi, 2911, Urbanova, 12244-000 São José dos Campos, SP, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: Ferreira-Strixino
authors.affiliation: Institute of Research and Development, Universidade do Vale do Paraíba, Univap, Avenida Shishima Hifumi, 2911, Urbanova, 12244-000 São José dos Campos, SP, Brazil.
authors.forename: Maiara L
authors.initials: ML
authors.lastname: Castilho
authors.affiliation: Federal University of São Paulo, Rua Talim, 330, 12231-280 São José dos Campos, São Paulo, Brazil.
authors.forename: Claudia B L
authors.initials: CB
authors.lastname: Campos
authors.affiliation: Institute of Research and Development, Universidade do Vale do Paraíba, Univap, Avenida Shishima Hifumi, 2911, Urbanova, 12244-000 São José dos Campos, SP, Brazil.
authors.forename: Claudio
authors.initials: C
authors.lastname: Tellez
authors.affiliation: Institute of Research and Development, Universidade do Vale do Paraíba, Univap, Avenida Shishima Hifumi, 2911, Urbanova, 12244-000 São José dos Campos, SP, Brazil. Electronic address: lraniero@pq.cnpq.br.
authors.forename: Leandro
authors.initials: L
authors.lastname: Raniero
mesh_terms: D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D006046:Gold / Q000737:chemistry*; D006801:Humans; D025282:Mycelium / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D015345:Oligonucleotide Probes / Q000737:chemistry* / Q000235:genetics; D010228:Paracoccidioides / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D010229:Paracoccidioidomycosis / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004271:DNA, Fungal; D015345:Oligonucleotide Probes; D006046:Gold
keywords: FT-IR; Gold nanoprobes; Mycelia; Paracoccidioides brasiliensis; Yeast