Evaluation of susceptibility and response in the surface of agents of surface mycoses (Trichophyton mentagrophytes; T. tonsurans) to antifungal drugs of interest in a medical clinic

Claudio José Dos Santos Júnior,Andressa Rafaelle De Lima Melo,Aryanna Kelly Pinheiro Souza,Maria Anilda Dos Santos Araújo,Silvana Maria Teixeira Da Silva,Jéssica Maria Diniz Do Nascimento

doi:10.7322/abcshs.2019162.1431

Abstract

Introduction: The resistance of fungal species to drugs usually used in clinics is of great interest in the medical field. Objective: To evaluate susceptibility and in vitro response of species of Trichophyton spp. to antifungal drugs of interest in clinical medicine. Methods: 12 samples of clinical isolates from humans were used, nine of T. mentagrophytes and three of T. tonsurans. Susceptibility tests were performed according to the agar diffusion (AD) and broth microdilution (BM) methods. Results: In the AD method, the species T. tonsurans presented a percentage of sensitivity of 33% in relation to amphotericin B and 66% to itraconazole, with 100% resistance to ketoconazole and fluconazole. T. mentagrophytes also showed 100% resistance to ketoconazole in this technique, with 11% sensitivity to ketoconazole, 22% to itraconazole and 22% of samples classified as sensitive dose dependent. In the MC method, the species T. tonsurans presented a sensitivity percentage of 66%, 55% and 33% in relation to ketoconazole, fluconazole and itraconazole, respectively. The T. mentagrophytes species presented sensitivity percentages of 11%, 11%, 33% and 55% for amphotericin B, itraconazole, ketoconazole and fluconazole, respectively. Conclusion: There was resistance in vitro of the species of T. mentagrophytes and T. tonsurans against the antifungal fluconazole and relative resistance against ketoconazole in the AD method. In BM, however, important percentages of sensitivity were observed for the two species analyzed in relation to the antifungals fluconazole and ketoconazole when compared to itraconazole and amphotericin B.

Highlights

The resistance of fungal species to drugs usually used in clinics is of great interest in the medical field
In the agar diffusion (AD) method, the species T. tonsurans presented a percentage of sensitivity of 33% in relation to amphotericin B and 66% to itraconazole, with 100% resistance to ketoconazole and fluconazole
Results were obtained regarding the sensitivity to antifungals of 12 isolates belonging to the genus Trichophyton spp., nine of the species T. mentagrophytes and three of the species T. tonsurans, from which the sensitivity test was carried out using agar diffusion techniques (Table 1) and the broth microdilution method (Table 2)

Summary

Introduction

The resistance of fungal species to drugs usually used in clinics is of great interest in the medical field. Results: In the AD method, the species T. tonsurans presented a percentage of sensitivity of 33% in relation to amphotericin B and 66% to itraconazole, with 100% resistance to ketoconazole and fluconazole. In the MC method, the species T. tonsurans presented a sensitivity percentage of 66%, 55% and 33% in relation to ketoconazole, fluconazole and itraconazole, respectively. The term dermatophytes are used to designate a group of fungi that invade keratinized tissues, such as the skin, nails, and hair of humans and animals, producing superficial mycoses called dermatophytoses[1]. ABCS Health Sci. 2021;46:e021203 genera: Trichophyton, Epidermophyton, Nannizzia, Paraphyton, Lophophyton, Microsporum and Arthroderma[2] Such microorganisms are differentiated in macroscopic, microscopic, physiological and molecular aspects, having as criteria in vitro morphological characters and combination of clinical pictures[2]. For example, there may be removal of edges, thickening, the appearance of white spots and total dystrophy of the nails[3]

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