Genetic Diversity of Cryptosporidium spp. within a Remote Population of Soay Sheep on St. Kilda Islands, Scotland

Abstract

This is the first report to characterize the genotypes and subtypes of Cryptosporidium species infecting a geographically isolated population of feral Soay sheep (Ovis aries) on Hirta, St. Kilda, Scotland, during two distinct periods: (i) prior to a population crash and (ii) as host numbers increased. Cryptosporidium DNA was extracted by freeze-thawing of immunomagnetically separated (IMS) bead-oocyst complexes, and species were identified following nested-PCR-restriction fragment length polymorphism (RFLP)/PCR sequencing at two Cryptosporidium 18S rRNA loci. Two hundred fifty-five samples were analyzed, and the prevalent Cryptosporidium species in single infections were identified as C. hominis (11.4% of all samples tested), C. parvum (9%), C. xiaoi (12.5%), and C. ubiquitum (6.7%). Cryptosporidium parvum was also present with other Cryptosporidium species in 27.1% of all samples tested. Cryptosporidium parvum-and C. hominis-positive isolates were genotyped using two nested-PCR assays that amplify the Cryptosporidium glycoprotein 60 gene (GP60). GP60 gene analysis showed the presence of two Cryptosporidium genotypes, namely, C. parvum IIaA19G1R1 and C. hominis IbA10G2. This study reveals a higher diversity of Cryptosporidium species/genotypes than was previously expected. We suggest reasons for the high diversity of Cryptosporidium parasites within this isolated population and discuss the implications for our understanding of cryptosporidiosis.

Comparative genomic analysis of the IId subtype family of Cryptosporidium parvum

“…In some areas such as Spain, Greece and Australia, IId subtypes are commonly found in lambs and goats whereas IIa subtypes are found in calves (Quilez et al, 2008a, b; Tzanidakis et al, 2014; Yang et al, 2014). IIa subtypes, however, have been seen in lambs in some countries including Spain (Geurden et al, 2008; Caccio et al, 2013; Connelly et al, 2013; Imre et al, 2013; Diaz et al, 2015), and in some areas such as China, Egypt and Sweden, calves are commonly infected with IId subtypes (Amer et al, 2013a, b; Silverlas et al, 2013; Wang et al, 2014). Therefore, direct comparative genomic analysis of IIa and IId specimens from areas known to have distinct distribution of the two subtype families between calves and lambs is needed to infer the role of subtelomeric gene duplications in host adaptation by C. parvum subtype families.…”

Periparturient transmission of Cryptosporidium xiaoi from ewes to lambs

“…However, sheep are now known to be commonly infected with C. xiaoi and C. ubiquitum in addition to C. parvum (Castro-Hermida et al, 2011;Connelly et al, 2013;Diaz et al, 2010;Imre et al, 2013;Leoni et al, 2007;McLauchlin et al, 2000;Mueller-Doblies et al, 2008;Paoletti et al, 2009;Pritchard et al, 2007;Quilez et al, 2008a;Ryan et al, 2005;Sweeny et al, 2011Sweeny et al, , 2012Wang et al, 2010;Yang et al, 2009). Although a dominant species in Europe (Castro-Hermida et al, 2011;Connelly et al, 2013;Diaz et al, 2010;Imre et al, 2013;Leoni et al, 2007;McLauchlin et al, 2000;Mueller-Doblies et al, 2008;Paoletti et al, 2009;Pritchard et al, 2007;Quilez et al, 2008a), C. parvum is not commonly found in sheep in other areas. Therefore, the species involved in periparturient shedding of Cryptosporidium oocysts in ewes is not clear.…”

Biology and Diseases of Reptiles

“…There are more than 25 species and greater than 60 genotypes of Cryptosporidium (Connelly et al, 2013). There are more than 25 species and greater than 60 genotypes of Cryptosporidium (Connelly et al, 2013).…”