The first report of Cryptosporidium bovis, C. ryanae and Giardia duodenalis sub-assemblage A-II in roe deer (Capreolus capreolus) in Spain

The aim of the present study was to identify the species and/or genotypes of Cryptosporidium and Giardia duodenalis infecting roe deer (Capreolus capreolus) in Galicia (NW Spain). The presence of both enteropathogens was investigated in 212 faecal samples from roe deer shot in diverse game preserves in three different areas of Galicia. The samples were analyzed by immunofluorescence microscopy and PCR amplification, and fragments of the 18S SSU rRNA gene of Cryptosporidium and the β-giardin gene of G. duodenalis were sequenced. In total, 9 samples (4.2%) were positive for Cryptosporidium and 19 samples (8.9%) for G. duodenalis. These samples tested positive with both techniques. However, gene sequencing was only possible for Cryptosporidium in 6 of the samples and for G. duodenalis in 7 of the samples. Cryptosporidium bovis was identified in 3 samples and C. ryanae oocysts were detected in another 3 samples. Sequencing of the amplicons identified G. duodenalis sub-assemblage A-II in 7 samples. Both Cryptosporidium and G. duodenalis infections were more prevalent in juvenile than in adult animals, although the differences were not significant. G. duodenalis was more prevalent than Cryptosporidium in both age groups, although again the differences were not statistically significant. The mean intensity of infection by Cryptosporidium and G. duodenalis was similar in both age groups and ranged between 5 and 225 oocysts/g and 5 and 320 cysts/g of faeces, respectively. This study represents the first molecular characterization of these parasites in Spanish roe deer. Identification of C. bovis and G. duodenalis sub-assemblage A-II indicates that zoonotic transmission of these enteropathogens between roe deer and humans is possible and that cross transmission of some Cryptosporidium species and G. duodenalis (sub-assemblage A-II) may occur between related animal species sharing the same habitats.