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.