title: Trichophyton tonsurans strains from Brazil: phenotypic heterogeneity, genetic homology, and detection of virulence genes.
abstract: The objective of this study was to establish the phenotypical and molecular patterns of clinical isolates of Trichophyton tonsurans circulating in the state of Ceará, northeastern Brazil. For this purpose, 25 T. tonsurans strains isolated from independent cases of tinea capitis in children were phenotypically evaluated regarding their macro- and micro-morphological characteristics, vitamin requirements, urease production, and antifungal susceptibility. The molecular characterization was carried out with random amplified polymorphic DNA molecular markers and M13 fingerprinting. The presence of the genes CarbM14, Sub2, CER, URE, ASP, PBL, and LAC, which encode enzymes related to fungal virulence, was also evaluated. Finally, melanin production was assessed through specific staining. The data obtained demonstrated that these T. tonsurans strains have considerable phenotypical variation, although they showed a low degree of genetic polymorphism according to the markers used. The genes CarbM14, Sub2, CER, and URE were detected in all the analyzed strains. The gene LAC was also identified in all the strains, and melanin synthesis was phenotypically confirmed. The strains were susceptible to antifungals, especially itraconazole (GM = 0.06 μg/mL) and ketoconazole (GM = 0.24 μg/mL). Therefore, T. tonsurans strains can present great phenotypical heterogeneity, even in genetically similar isolates. Moreover, the presence of the LAC gene indicates the possible participation of melanin in the pathogenesis of these dermatophytes.
authors.affiliation: a Postgraduate Program in Medical Science, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors.forename: José Julio Costa
authors.initials: JJ
authors.lastname: Sidrim
authors.forename: Marcos Fábio Gadelha
authors.initials: MF
authors.lastname: Rocha
authors.forename: João Jaime Giffoni
authors.initials: JJ
authors.lastname: Leite
authors.forename: Fernanda Cristina de Albuquerque
authors.initials: FC
authors.lastname: Maranhão
authors.forename: Rita Amanda Chaves
authors.initials: RA
authors.lastname: Lima
authors.forename: Débora de Souza Collares Maia
authors.initials: Dde S
authors.lastname: Castelo-Branco
authors.forename: Tereza de Jesus Pinheiro Gomes
authors.initials: Tde J
authors.lastname: Bandeira
authors.forename: Rossana de Aguiar
authors.initials: Rde A
authors.lastname: Cordeiro
authors.forename: Raimunda Sâmia Nogueira
authors.initials: RS
authors.lastname: Brilhante
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D001938:Brazil / Q000453:epidemiology; D002648:Child; D016172:DNA Fingerprinting; D005838:Genotype; D006801:Humans; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D019105:Random Amplified Polymorphic DNA Technique; D015183:Restriction Mapping; D012535:Scalp / Q000382:microbiology; D014006:Tinea Capitis / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*; D014249:Trichophyton / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000935:Antifungal Agents; D037521:Virulence Factors