ITS-RFLP optimization for dermatophyte identification from clinical sources in Alagoas (Brazil) versus phenotypic methods.

INTRODUCTION: Dermatophytoses are superficial mycoses, and the identification of their etiological agents is routinely performed by culture and microscopic features, which is time-consuming and relies on personnel expertise. Molecular approaches have been developed to provide faster and reliable results; therefore, this study aimed to identify dermatophytes isolated from Alagoas state patients, employing phenotypical and molecular methods. METHODOLOGY: Clinical samples for morphological identification were collected from private and public laboratories and cultivated on Sabouraud dextrose agar. DNA extraction was followed by ITS amplicon analysis after restriction enzyme digestion DdeI (ITS-RFLP). RESULTS: Out of fourteen representative strains, ITS-RFLP with DdeI efficiently identified Microsporum canis, Nannizzia gypsea, and Trichophyton rubrum, while species of the complex T. tonsurans/T. mentagrophytes presented the same restriction pattern. After genotyping, 2 T. tonsurans and 1 Microsporum sp. strain were reclassified as T. rubrum. CONCLUSIONS: RFLP of ITS-region followed by DdeI digestion produced faster and relatively reliable results than classic methods; however, this method has not been as efficient for closely related dermatophytes cryptic species.

Mycoses in northeastern Brazil: epidemiology and prevalence of fungal species in 8 years of retrospective analysis in Alagoas.

Superficial and cutaneous mycoses are common in tropical countries, caused by dermatophytes, yeast, and non-dermatophyte molds in different clinical specimens. In order to define the epidemiology of mycoses and the profile of their etiological agents in Alagoas (northeastern Brazil) between 2009 and 2016, we obtained data of patients from the main laboratories of Alagoas, by examining clinical samples with direct microscopy and culture on Sabouraud dextrose agar and Chromagar®Candida. A total of 3316 patients were confirmed with mycoses (595 men/2716 women) and 40.25 of average age. Positive samples totaled 3776, mainly vaginal secretion (1593/42.2%), toenails (876/23.2%), and fingernails (589/15.6%). Yeasts were the most isolated (3129/82.9%), including 3012 Candida spp. (79.8%), 57 Malassezia spp. (1.5%), 42 Trichosporon sp. (1.1%), 10 Geotrichum spp. (0.3%), and 8 Rhodotorula spp. (0.2%). Candida albicans was the most frequent species (715/18.9%), followed by C. krusei (194/5.1%), C. tropicalis (24/0.6%), and 2079 unspecified species (55.1%). Among 17.1% filamentous fungi, 14.8% dermatophytes were distributed as 211 Trichophyton sp. (5.6%), 125 T. rubrum (3.3%), 106 T. tonsurans (2.8%), 72 T. mentagrophytes (1.9%), 2 Microsporum sp. (0.1%), 15 M. canis (0.4%), and 26 Epidermophyton sp. (0.7%). Other fungi represented the minority: Fusarium sp. and Aspergillus sp. These are the first clinical data on the Alagoas population affected by fungi pathogens, confirming a higher incidence of candidiasis (mainly vulvovaginal and onychomycosis) and dermatophytes, providing a better understanding of different mycoses in northeastern Brazil.