Molecular survey of Besnoitia spp. (Apicomplexa) in faeces from European wild mesocarnivores in Spain.

Abstract

Numerous studies have unsuccessfully tried to unravel the definitive host of the coccidian parasite Besnoitia besnoiti. Cattle infections by B. besnoiti cause a chronic and debilitating condition called bovine besnoitiosis that has emerged in Europe during the last two decades, mainly due to limitations in its control associated to the absence of vaccines and therapeutical tools. Although the exact transmission pathway of B. besnoiti is currently unknown, it is assumed that the parasite might have an indirect life cycle with a carnivore as definitive host. Current lack of studies in wildlife might underestimate the importance of free-living species in the epidemiology of B. besnoiti. Thus, the aim of the present study is to assess the presence of Besnoitia spp. in free-ranging mesocarnivores in Spain. DNA was searched by PCR on faeces collected from wild carnivores as a first approach to determine which species could be considered as potential candidates for definitive hosts in further research. For this purpose, a total of 352 faecal samples from 12 free-living wild carnivore species belonging to the Canidae, Felidae, Herpestidae, Mustelidae, Procyonidae, and Viverridae families were collected in seven Spanish regions. PCR testing showed that Besnoitia spp. DNA was present in four faecal samples from red foxes collected in western Spain, an area with the greatest density of extensively reared cattle and associated to high incidence of bovine besnoitiosis in the country. To date, this is the first report of a Besnoitia besnoiti-like sequence (99.57% homology) from carnivore faeces in a worldwide context. Red foxes might contribute to the epidemiology of B. besnoiti, although further studies, mostly based on bioassay, would be needed to elucidate the accuracy and extent of these interesting findings.

Patterns of Exposure and Infection with Microparasites in Iberian Wild Carnivores: A Review and Meta-Analysis

“…In the search for this unknown host, Millán et al [ 64 ] analyzed more than 160 serum samples from wild carnivores from 14 species with negative results. González-Barrio et al [ 97 ] analyzed fecal samples from 12 carnivores, obtaining sequences closely related to B. besnoiti in red foxes, resulting in the first detection in a fecal sample of a wild carnivore worldwide. Nevertheless, the lack of complementary techniques to confirm this finding and the fact that genomic material found in the feces of predators can be part of their diet limits the interpretation of these results.…”

Absence of anti‐ Besnoitia spp. specific antibodies in European wild lagomorphs from the Iberian Peninsula

“…Additionally, in a recent study, González‐Barrio, Köster et al. (2021) detected Besnoitia spp. DNA in four faecal samples from red foxes collected in western Spain.…”

“…Studies in other Iberian host species, including domestic (equids, small ruminants) and wild (carnivores, ruminants) animals, have been performed to elucidate their role in the life cycle of Besnoitia spp. (Gutiérrez‐Expósito et al., 2016; Gutiérrez‐Expósito, Ortega‐Mora, et al., 2017; Gutiérrez‐Expósito, García‐Bocanegra, et al., 2017; González‐Barrio, Köster, et al., 2021; Millán et al., 2012). The most relevant findings of those surveys were the identification of roe deer and red deer as intermediate hosts of B. besnoiti (Gutiérrez‐Expósito et al., 2016) and the apparent lack of involvement of sheep and goats in the Besnoitia spp.…”