title: Cryptosporidium ryanae n. sp. (Apicomplexa: Cryptosporidiidae) in cattle (Bos taurus).
abstract: A new species, Cryptosporidium ryanae, is described from cattle. Oocysts of C. ryanae, previously identified as the Cryptosporidium deer-like genotype and recorded as such in GenBank (AY587166, EU203216, DQ182597, AY741309, and DQ871345), are similar to those of Cryptosporidium parvum and Cryptosporidium bovis but smaller. This genotype has been reported to be prevalent in cattle worldwide. Oocysts obtained from a calf for the present study are the smallest Cryptosporidium oocysts reported in mammals, measuring 2.94-4.41micromx2.94-3.68microm (mean=3.16micromx3.73microm) with a length/width shape index of 1.18 (n=40). The pre-patent period for two Cryptosporidium-naïve calves fed C. ryanae oocysts was 11 days and the patent period was 15-17 days. Oocysts were not infectious for BALB/c mice or lambs. Fragments of the SSU-rDNA, HSP-70, and actin genes amplified by PCR were purified and PCR products were sequenced. Multi-locus analysis of the three unlinked loci demonstrated the new species to be distinct from all other species and also demonstrated a lack of recombination, providing further evidence of species status. Based on morphological, molecular and biological data, this geographically widespread parasite found only in Bos taurus calves is recognized as a new species and is named C. ryanae.
authors.affiliation: Environmental Microbial 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. rfayer@anri.barc.usda.gov
authors.forename: Ronald
authors.initials: R
authors.lastname: Fayer
authors.forename: Mónica
authors.initials: M
authors.lastname: Santín
authors.forename: James M
authors.initials: JM
authors.lastname: Trout
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D003457:Cryptosporidiosis / Q000469:parasitology / Q000662:veterinary*; D003458:Cryptosporidium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000469:parasitology; D005260:Female; D005838:Genotype; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010802:Phylogeny; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology