Molecular characterization of Enterocytozoon bieneusi in wild carnivores in Spain

Authors: Santin-Duran, Monica; CALERO-BERNAL, RAFAEL - US Department Of Agriculture (USDA); CARMENA, DAVID - Instituto De Salud Carlos Iii; MATEO, MARTA - Instituto De Salud Carlos Iii; BALSEIRO, ANA - Agriculture Research And Development Service (SERIDA); BARRAL, MARTA - Neiker-Instituto Vasco De Investigacion Y Desarrollo Arario; LIMABARBERO, JOSE - Wildlife Health And Control; HABELA, MIGUEL - University Of Extremadura

Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/2017
Publication Date: 12/12/2017
Citation: Santin, M., Calero-Bernal, R., Carmena, D., Mateo, M., Balseiro, A., Barral, M., Limabarbero, J.F., Habela, M.A. 2017. Molecular characterization of Enterocytozoon bieneusi in wild carnivores in Spain. Journal of Eukaryotic Microbiology. 65(4):468-474. https://doi.org/10.1111/jeu.12492.
DOI: https://doi.org/10.1111/jeu.12492

Interpretive Summary: Microsporidia are parasites of medical and veterinary concern that that are transmitted through contaminated water and food to humans resulting primarily in intestinal infections characterized by diarrheal disease. Among Microsporidia, Enterocytozoon bieneusi is the most frequently detected species in humans and animals worldwide bringing into question the possible role of animal reservoirs in the epidemiology of this pathogen. Although E. bieneusi is zoonotic pathogen able to infect many domestic and wild mammals that could act as reservoir of infection for humans and other animals, only few studies have documented its occurrence in wild carnivores. To determine the occurrence of E. bieneusi, we examined 190 wild carnivores collected from different locations in Spain. Twenty-five samples (13.2%) from 3 host species (European badger, beech marten, and red fox) were E. bieneusi-positive by PCR. Molecular characterization of the internal transcribed spacer (ITS) revealed 8 genotypes; 4 previously reported (PtEbIX, S5, S9, and WildBoar3) and 4 novel genotypes (EbCar1-EbCar4). This study has expanded the host range of this parasite with two new hosts (beech martin, and European badger) and demonstrated that E. bieneusi is a common parasite in wild carnivores suggesting they could contribute to environmental contamination. Additionally, results demonstrate that human-pathogenic genotypes are present, corroborating the potential role of wild carnivores as reservoirs for this parasite and as a source of human infection and environmental contamination. This information should be useful to other scientists, veterinarians and public health agencies.

Technical Abstract: Microsporidia comprises a diverse group of obligate intracellular parasites that infect a broad range of invertebrates and vertebrates. Among Microsporidia, Enterocytozoon bieneusi is the most frequently detected species in humans and animals worldwide bringing into question the possible role of animal reservoirs in the epidemiology of this pathogen. Although E. bieneusi is an emerging zoonotic pathogen able to infect many domestic and wild mammals that could act as reservoir of infection for humans and other animals, only few studies have documented its occurrence in wild carnivores. To determine the occurrence of E. bieneusi in wild carnivores, we examined 190 wild carnivores collected from different locations in Spain. Twenty-five fecal samples (13.2%) from 3 host species (European badger, beech marten, and red fox) were E. bieneusi-positive by PCR. Nucleotide sequence analysis of the ITS region revealed a high degree of genetic diversity with a total of 8 distinct genotypes including 4 known (PtEbIX, S5, S9, and WildBoar3) and 4 novel (EbCar1-EbCar4) genotypes identified. Phylogenetic analysis showed that the four novel genotypes (EbCar1-EbCar4) and S5, S9, and WildBoar3 clustered within the previously designated zoonotic Group 1. Our results demonstrate that human-pathogenic genotypes are present in wild carnivores, corroborating their potential role as a source of human infection and environmental contamination.