Molecular survey of Besnoitia spp. (Apicomplexa) in faeces from European
wild mesocarnivores in Spain. Short running title: Molecular survey of
Besnoitia spp in faeces from wild carnivores.
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 definitive host candidates 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.