Yeast microbiota of free-ranging amphibians and reptiles from Caatinga biome in Ceará State, Northeast Brazil: High pathogenic potential of Candida famata

Abstract

Studies on the fungal microbiota of reptiles and amphibians are necessary to better understand of host-microbe interactions and the establishment of fungal disease in these animals. However, these studies are limited. The present researchidentified yeasts from free-ranging reptiles and amphibians from the Caatinga biome andevaluated the virulence factors production, the antifungal susceptibility in planktonic and biofilm growth and the pathogenicity of Candida famata isolates. Twenty-nine isolates of the genera Candida, Cryptococcus and Rhodotorula were identified by phenotypic and/or molecular methods and production of hydrolytic enzymes in vitro by these genera of fungi was evaluated. In addition, susceptibility of planktonic cells and biofilms to azoles and amphotericin B was evaluated. The pathogenicity of C. famata, the most prevalent yeast species isolated, was evaluated using Caenorhabditis elegans model. C. famata was the most prevalent yeast in amphibian and reptilian microbiota. Phospholipase and protease production was observed in 18/29 and 11/29 of the yeast isolates, respectively, while 100% formed biofilms. Itraconazole presented high minimal inhibitory concentrations against C. famata and C. tropicalis. Amphotericin B reduced the biomass and metabolic activity of biofilms. C. famata induced the mortality of C. elegans. In conclusion, reptiles and amphibians are colonized by yeasts capable of producing important virulence factors, especially by Candida spp. that present low susceptibility to azoles which may result from imbalances in ecosystem. Finally, C. famata isolated from these animals presented high pathogenicity, showing the importance of the study of reptile and amphibians fungal microbiota.

Investigation of filamentous fungi in wild Caatinga biome reptiles: microbiota research

“…Cordeiro et al., 2015;Svedese et al, 2017;Castelo-Branco et al, 2021). Amongst the prevalent genera in this study, Aspergillus, followed by Penicillium and Microsporum, are correlated to diseases in animals and humans(Moss, 2016; Elad; Segal, 2018; Gnat et al, 2018; Aneke et al, 2021).…”

“…Nevertheless, studies on the description and characterization of the lamentous fungal microbiota in wild reptile species are scarce (Brilhante et al, 2015;Svedese et al, 2017;Castelo-Branco et al, 2021). Thus, this study aimed to isolate and identify lamentous fungi present in the oral cavity microbiota and cloaca of free-living reptiles.…”

“…Studies describing the microbiota of animals are fundamental to understanding the microbiota-host interaction. In this regard, research characterizing the microbiota of reptiles has gained numbers in the literature (Brilhante et al, 2015;Svedese et al, 2017;Vega-Manriquez et al, 2018;Castelo-Branco, et al, 2021). Since bacteria and fungi associated or not with the animal microbiota may become pathogens under speci c circumstances, these studies are of paramount importance for a better understanding of the biology and health of these animals, whereas intra and inter-species communication can play a major role in disease transmission (Hernádez-Gómez et al, 2020).…”

Collateral consequences of agricultural fungicides on pathogenic yeasts: A One Health perspective to tackle azole resistance

“…The most frequently colonised anatomical sites include the gastrointestinal, urogenital and respiratory tracts, eye conjunctiva, ear canal and skin 59 . Candida albicans , C tropicalis , C parapsilosis , C famata , C krusei , C guilliermondii and C glabrata are the most commonly described commensal species 60‐69 . Candida may act as primary pathogens, causing oral, esophageal or crop candidiasis in birds and mastitis in cows.…”

“…As opposed to human clinical isolates, antifungal susceptibility testing of Candida from veterinary sources is seldom performed. Nevertheless, there is an increasing number of reports of azole‐resistant Candida from various animal species, including wild and domestic mammals, birds, reptiles and crustaceans 60‐69 . These findings suggest the presence of an intense selective pressure in animal‐associated microbial niches, which is particularly intriguing because systemic antifungal drugs are not commonly used in veterinary practices, and resistant isolates have been recovered from wild animals 62 …”