Chlamydoconidium-producing Trichophyton tonsurans: Atypical morphological features of strains causing tinea capitis in Ceará, Brazil
Raimunda Sâmia Nogueira Brilhante1, Germana Costa Paixäo1, Jonathas Sales de Oliveira1, Vandbergue Santos Pereira1, Marcos Fábio Gadelha Rocha2, Reginaldo Gonçalves de Lima-Neto3, Debora de Souza Collares Maia Castelo-Branco1, Rossana de Aguiar Cordeiro1, Jose Julio Costa Sidrim1
1 Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Federal University of Ceará, Rua Nunes de Melo, 1315, Fortaleza, Brazil
2 Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Federal University of Ceará, Rua Nunes de Melo, 1315; Postgraduate Program in Veterinary Sciences, State University of Ceará; Av. Dr. Silas Munguba, 1700, Fortaleza, Brazil
3 Department of Tropical Medicine, Center for Health Sciences, Federal University of Pernambuco, Recife-PE, Brazil
Marcos Fábio Gadelha Rocha
Rua Coronel Nunes de Melo, 1315, Rodolfo Teófilo, CEP: 50430-275. Fortaleza, CE
Source of Support: This work was supported by the Conselho Nacional de Desenvolvimento
Cientifico e Tecnológico-CNPq, Brazil(Grant No.: 306976/2017-0), Conflict of Interest: None
Objective: To report atypical morphological features of Trichophyton (T.) tonsurans strains associated with tinea capitis.
Methods: Eighty-two T. tonsurans strains isolated in Ceará, Brazil, were analyzed regarding macro and micromorphological features and nutritional patterns.
Results: Fifty-two samples presented abundant chlamydoconidia, which were produced in chains. Macroscopically, these strains developed small glabrous colonies that were firmly attached to the surface of the culture medium, with few or no aerial mycelia and intense rusty yellow pigmentation. Seven strains did not grow with stimulus from thiamine. Samples were heterogeneous regarding urease production and none presented in vitro hair perforation.
Conclusions: The observation of T. tonsurans strains with distinct phenotypic features indicates the need to revise the taxonomic criteria for routine identification of this dermatophyte.