Sarcocystis spp. Investigations in Iberian Wild Caprinae Reveal a Remarkable Degree of Interconnection with Parasites' Domestic Epidemiological Life Cycles.

Many uncertainties exist on the epidemiology of the Sarcocystis species infecting wild ruminants. In this study, tongue and/or diaphragm tissues of free-ranging wild Caprinae species (54 Pyrenean chamois, 52 mouflons, 146 Iberian ibexes, and 19 Balearean wild goats) residing in the mountain areas of Spain were selected for Sarcocystis spp. detection and species identification. By light microscopy, Sarcocystis sarcocyst frequency rates were considerably high (85.7% in chamois, 82.7% in mouflon, 52.7% in Iberian ibexes), except for the Balearean wild goat (5.3%), which was investigated for the very first time. One excised sarcocyst of Iberian ibex was subjected to transmission electron microscopy, revealing a sibling S. capracanis ultrastructure. Genomic DNA isolated from 57 sarcocysts excised from the hosts' tissues was investigated through PCR amplicon sequencing of the 18S rRNA and cox1 genes. As a result, sequences of S. capracanis, S. cornagliai, S. rossii and S. tenella were detected, sharing high identity with conspecific sequences. Phylogenetic analyses confirmed a remarkable clustering of all Sarcocystis species in clades encompassing species transmitted via canids, except S. cornagliai, which is allocated in a clade with species using corvid birds as their definitive hosts. Therefore, a significant degree of interconnection between sylvatic and domestic Sarcocystis epidemiological cycles can be drawn in the study area.