title: Longitudinal prevalence, oocyst shedding and molecular characterisation of Cryptosporidium species in sheep across four states in Australia.
abstract: The prevalence of Cryptosporidium in sheep in the eastern states of Australia has not been well described, therefore a study of the prevalence, oocyst concentration, species and subtypes of Cryptosporidium were assessed from lamb faecal samples at three sampling periods (weaning, post-weaning and pre-slaughter) from eight farms across South Australia, New South Wales, Victoria and Western Australia. A total of 3412 faecal samples were collected from approximately 1182 lambs across the four states and screened for the presence of Cryptosporidium using a quantitative PCR (qPCR) at the actin locus. Positives were typed at the 18S locus and at a second locus using C. parvum and C. hominis specific qPCR primers. The overall prevalence was 16.9% (95% CI: 15.6-18.1%) and of the 576 positives, 500 were successfully genotyped. In general, the prevalence of Cryptosporidium was higher in WA than the eastern states. Cryptosporidium prevalence peaked at 43.9% and 37.1% at Pingelly (WA2) and Arthur River (WA1), respectively during weaning and at Pingelly (WA2) during pre-slaughter (36.4%). The range of oocyst shedding at weaning overall across all states was 63-7.9×10(6) and the median was 3.2 × 10(4) oocysts g(-1). The following species were identified; C. xiaoi (69%-345/500), C. ubiquitum (17.6%-88/500), C. parvum (9.8%-49/500), C. scrofarum (0.8%-4/500), mixed C. parvum and C. xiaoi (2.4%-12/500), C. andersoni (0.2%-1/500) and sheep genotype 1 (0.2%-1/500). Subtyping of C. parvum and C. ubiquitum isolates identified IIa and IId subtype families within C. parvum (with IId as the dominant subtype) and XIIa within C. ubiquitum. This is the first published description of C. parvum subtypes detected in lambs in Australia.
authors: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Perth 6150, WA, Australia.
authors: Rongchang
authors: R
authors: Yang
authors: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Perth 6150, WA, Australia.
authors: Caroline
authors: C
authors: Jacobson
authors: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Perth 6150, WA, Australia.
authors: Graham
authors: G
authors: Gardner
authors: South Australian Research and Development Institute, 33 Flemington Street, Glenside 5065, SA, Australia.
authors: Ian
authors: I
authors: Carmichael
authors: Faculty of Veterinary Science, University of Melbourne, 250 Princes Highway, Werribee 3030, VIC, Australia.
authors: Angus J D
authors: AJ
authors: Campbell
authors: South Australian Research and Development Institute, 33 Flemington Street, Glenside 5065, SA, Australia.
authors: Josephine
authors: J
authors: Ng-Hublin
authors: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Perth 6150, WA, Australia. Electronic address: Una.Ryan@murdoch.edu.au.
authors: Una
authors: U
authors: Ryan
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D001315:Australia / Q000453:epidemiology; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000469:parasitology*; D003458:Cryptosporidium / Q000145:classification* / Q000235:genetics*; D016054:DNA, Protozoan / Q000235:genetics; D005243:Feces / Q000469:parasitology; D005838:Genotype; D033661:Oocysts / Q000502:physiology*; D059208:Parasite Load; D016133:Polymerase Chain Reaction / Q000592:standards / Q000662:veterinary; D015995:Prevalence; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012680:Sensitivity and Specificity; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology* / Q000469:parasitology*
chemical_list: D000199:Actins; D016054:DNA, Protozoan; D012337:RNA, Ribosomal, 18S
keywords: 18S rRNA; Actin; Cryptosporidium; Lambs; gp60; qPCR