Fungal community on skin tissue of amphibians collected in the Santarém region, Pará, Brazil / Comunidade de fungos do tecido cutâneo de anfíbios coletados na região de Santarém, Pará, Brasil

Abstract

Among living beings, the Amphibia Class has unique characteristics. The cutaneous tissue of these animals has properties that provide ideal conditions for the establishment of microorganisms in their skin, which act in several important functions. The present study aimed to characterize the cultivable fungal microbiota of amphibians collected in the Santarém region, Western Pará, Brazil. Two species of toads were captured, totalling 25 individuals, being 15 specimens of Rhinella major and 10 individuals of R. marina. Collections were performed by active search at night, between the months of November 2017 to April 2019. Cutaneous samples were collected by smear in the dorsoventral region of the animal, using a swab soaked in sterile 0.85% saline solution with 10-3 dilution, and grown in Petri dishes containing Potato Dextrose Agar culture medium. The animals were euthanized and deposited in the herpetological collection of Federal University of Western Pará. For identification, isolation, morphological characterization and microculture of fungal colonies were used. In total, 75 fungal colonies representative of 11 genera were identified. Penicillium and Aspergillus have been identified as the most representative genera in both amphibian species. There were differences in the composition of the cutaneous mycobiota between R. major and R. marina, but not related to seasonality, which may be linked to the environment they inhabit, as well as to the physiological factors inherent to each species. The present work presents the taxa Absidia, Curvularia, Scopulariopsis and the group mycelia sterilia as new records of fungi associated with the skin tissue of adult anurans. Thus, it is suggested that further studies be carried out in Amazonian environments, with a larger sample size, as well as the use of molecular tools, for a better identification and understanding of the composition of the anuran skin microbiota