Isolamento e identificação de fungos associados às lesões suspeitas de dermatomicoses de pacientes atendidos no ambulatório de dermatologia do Hospital de Clínicas da Universidade Federal do Triângulo Mineiro (HC-UFTM), e avaliação do uso de Azul de Tripan no exame microscópico direto

Abstract

Dermatomycoses are fungal diseases of worldwide occurrence, with higher prevalence in tropical and subtropical regions, and are among the most common dermatological diseases in humans. They are classified as superficial mycoses and are caused by filamentous fungi, dermatophytes and non-dermatophytes, and yeasts. To make the diagnosis of these fungal infections, a clinical examination of the lesions presented is performed, and, when there is a suspicion of mycosis, the doctor refers the patient to a laboratory mycological examination, which helps in the differentiation of mycoses from other dermatological lesions. In addition, considering the diversity of species that can cause dermatomycoses, the identification of the etiological agent contributes to directing the appropriate treatment for each case, increasing cure rates, providing the establishment of prophylactic measures and generating data that can be used in epidemiological studies. Therefore, the importance of correctly identifying the species that cause dermatomycoses in humans becomes evident. For this correct and fast identification it is necessary that the diagnostic methods are improved and accessible to routine laboratories. Thus, in addition to isolating and identifying fungi associated with suspected dermatomycosis lesions in patients seen in the Outpatient Dermatology Unit at the Clinical Hospital of the Federal University of Triângulo Mineiro (HC-UFTM), this study also aimed to improve the sensitivity of the direct examination, evaluating the use of Trypan Blue (TA) dye in the direct microscopic examination with or without KOH, analyzed both in direct microscopy and in fluorescence microscopy. The collected samples were used to characterize the dermatomycoses found in the region covered by the HC-UFTM. Onychomycosis was the most frequent type of infection, followed by interdigitoplantar lesions. Among the isolated fungi, 49.5% were dermatophytes, 30.7% were yeasts and 19.8% were non-dermatophytic filamentous fungi (FFND), with the genera Trichophyton, Candida and Scytalidium being the most frequent, respectively in each fungal group. The investigation of the use of Trypan Blue revealed the unique property of this fungal dye in being able to be used both in bright field microscopy and in fluorescence microscopy for the diagnosis of superficial mycoses.