Exploring fungal diversity in Antarctic wildlife: isolation and molecular identification of culturable fungi from penguins and pinnipeds
Creators: name: Devoto, T Brito
name: Toscanini, MA
name: Alava, K Hermida
name: Etchecopaz, AN
name: Pola, SJ
name: Martorell, MM
name: Ansaldo, M
name: Negrete, J
name: Ruberto, L
name: Mac Cormack, W
name: Cuestas, ML
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Evolutionary Biology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Computational Biology

description: To survey the diversity of fungal species that may be cultured from Antarctic penguins and pinnipeds, and to test the <i>in vitro</i> susceptibility to triazole drugs of any medically important <i>Aspergillu</i>s spp. isolates. During an expedition to Argentinean Antarctic research stations at Potter Peninsula (South Shetland Islands) and Primavera Cape (Antarctic Peninsula) in February 2019, samples (n = 212) were collected from fur seals (<i>Arctocephalus gazella</i>), elephant seals (<i>Mirounga leonine</i>), leopard seals (<i>Hydrurga leptonyx</i>), Weddell seals (<i>Leptonychotes weddellii</i>) and crabeater seals (<i>Lobodon carcinophaga</i>) and gentoo penguins (<i>Pygoscelis papua</i>). Oral, nasal and rectal swabs and skin/hair brushings were collected from pinnipeds, and skin/feather brushings, cloacal swabs and moulted feathers from penguins. Samples were cultured on Sabouraud dextrose agar and/or potato dextrose agar plates and fungal isolates identified by morphological criteria followed by PCR amplification and DNA sequencing. Antifungal susceptibility of <i>Aspergillus</i> spp. isolates to triazoles was tested. Fungi from 21 genera were isolated from 121/212 (57.1%) samples obtained from pinnipeds and penguins. Among pinnipeds from Potter Peninsula (fur seals and elephant seals), the most frequent fungal species were <i>Debaryomyces hansenii</i> and <i>Rhodotorula mucilaginosa</i>, isolated from the oral, nasal and/or rectal mucosa, and <i>Antarctomyces psychrotrophicus</i> isolated from the skin/hair of all sampled individuals. Among pinnipeds from Primavera Cape (leopard seals, Weddell seals and crabeater seals), the most frequent fungal species were <i>Naganishia adeliensis</i> and <i>Cryptococcus neoformans</i> var. <i>uniguttulatus</i>, isolated from the nasal/oral mucosa of 4/33 (15.2%) and 5/33 (12.1%) animals, respectively. The most frequently isolated fungal species from gentoo penguins (Potter Peninsula), were <i>Pseudogymnoascus pannorum</i> and <i>A. pyschrotrophicus</i>, which both were isolated from skin/feathers of 7/15 (46.7%) birds, and <i>Thelebolus microsporus</i>, isolated from the cloacal mucosa and skin/feathers of 5/15 (33.3%) and 2/15 (13.3%) birds, respectively. Fungi that are potentially pathogenic to both humans and animals (<i>Aspergillus fumigatus, Asp. flavus, Asp. versicolor, Candida parapsilosis</i> and <i>Microsporum canis</i>) were isolated from 4/38 (10.5%), 1/38 (2.6%), 2/38 (5.3%), 4/38 (10.5%) and 2/38 (5.3%) sampled pinnipeds, respectively. Only non-azole-resistant isolates of <i>Asp. fumigatus</i> and <i>Asp. flavus</i> were identified. The fungal biodiversity in Antarctic pinnipeds and gentoo penguins was explored using standard mycological culture followed by PCR and DNA sequencing. The frequency of fungal carriage varied among animal species, sample type and location. This study constitutes an epidemiologic approach to monitoring of these marine animals for emerging fungal pathogens.