title: Cryptosporidium xiaoi n. sp. (Apicomplexa: Cryptosporidiidae) in sheep (Ovis aries).
abstract: A new species, Cryptosporidium xiaoi, is described from sheep. Oocysts of C. xiaoi, previously identified as the Cryptosporidium bovis-like genotype or as C. bovis from sheep in Spain, Tunisia, United Kingdom, and the United States are recorded as such in GenBank (EU408314-EU408317, EU327318-EU327320, EF362478, EF514234, DQ991389, and EF158461). Oocysts obtained from naturally infected sheep were infectious for a lamb and oocysts from that lamb were infectious for three other lambs. The prepatent period for C. xiaoi in these four Cryptosporidium-naive lambs was 7-8 days and the patent period was 13-15 days. Oocysts are similar to those of C. bovis but slightly smaller, measuring 2.94-4.41 microm x 2.94-4.41 microm (mean=3.94 microm x 3.44 microm) with a length/width shape index of 1.15 (n=25). Oocysts of C. xioai were not infectious for BALB/c mice, Bos taurus calves, or Capra aegagrus hircus kids. Fragments of the SSU-rDNA, HSP-70, and actin genes were amplified by PCR, purified, and PCR products were sequenced. The new species was distinct from all other Cryptosporidium species as demonstrated by multi-locus analysis of the 3 unlinked loci. Based on morphological, molecular and biological data, this geographically widespread parasite found in Ovis aries is recognized as a new species and is named C. xiaoi.
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agriculture, Building 173, BARC-East, 10300 Baltimore Avenue, Beltsville, MD 20705, USA. ronald.fayer@ars.usda.gov
authors.forename: Ronald
authors.initials: R
authors.lastname: Fayer
authors.forename: Mónica
authors.initials: M
authors.lastname: Santín
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D003458:Cryptosporidium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000469:parasitology; D005260:Female; D015511:Goat Diseases / Q000469:parasitology; D006041:Goats; D008297:Male; D008396:Maryland / Q000453:epidemiology; D051379:Mice; D010802:Phylogeny; D015995:Prevalence; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000469:parasitology*; D013045:Species Specificity