Studies on the prevalence and molecular characterization of Cryptosporidium spp. affecting feral horses are scarce. The highland areas of the northern Iberian Peninsula are home to a large population of wild ponies which generally roam free in the ancient natural range and are subjected to a traditional exploitation regime. In the present study, a total of 79 non-diarrhoeal faecal samples from the wild ponies were collected from the ground immediately after defecation. Cryptosporidium was detected in 10 of the samples (12.6%) by a direct immunofluorescence antibody test and DNA amplification and sequencing. Analysis of partial sequences of the small subunit ribosomal RNA (SSU-rRNA) and heat shock protein (hsp70) loci revealed the presence of Cryptosporidium parvum. In addition, amplification and sequencing of a fragment of the 60-kDa glycoprotein (GP60) locus identified C. parvum subtypes IIaA15G2R1 and IIaA16G3R1. This study reports, for the first time, the occurrence of C. parvum in wild ponies in Europe, specifically in the northern Iberian Peninsula. Identification of the common subtype IIaA15G2R1 and also subtype IIaA16G3R1 (first description) indicates that these hosts may play a role in the sylvatic transmission of C. parvum and that they may act as a reservoir of zoonotic cryptosporidiosis.
Keywords: Cryptosporidium parvum; Iberian Peninsula; Immunofluorescence microscopy; Molecular characterization; Wild ponies.