title: Longitudinal prevalence, oocyst shedding and molecular characterisation of Eimeria species in sheep across four states in Australia.
abstract: The prevalence of Eimeria in sheep in Australia has not been well described, therefore a quantitative PCR (qPCR) was developed, validated and used to study the prevalence and oocyst concentration in 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 4 states and screened for the presence of Eimeria using this qPCR at the 18S ribosomal RNA (rRNA) locus. A subset of positives was typed by sequence analysis at the 18S locus. The overall prevalence was 18.1% (95% CI 16.8-19.3%) and of the 616 positives, 118 were successfully genotyped. The prevalence of Eimeria was highest in NSW and peaked at 70% during the post-weaning period. The range of oocyst shedding per gram of faeces (g(-1)) at weaning, post-weaning and pre-slaughter overall across all states was 23-2.1×10(7), 23-1.3×10(7) and 23-2.1×10(5), respectively. Median Eimeria shedding g(-1) was higher during post-weaning (1.1×10(3)) and pre-slaughter (1.1×10(3)) than during weaning (206). The following species were identified: Eimeria crandallis, Eimeria ahsata, Eimeria ovinoidalis, Eimeria weybridgensis and Eimeria cylindrica. Of these, E. crandallis and E. ovinoidalis, the most pathogenic species in sheep were responsible for 58.5% of infections typed. This highlights a need for further research to quantify the production impacts of Eimeria in sheep.
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.
authors.forename: Rongchang
authors.initials: R
authors.lastname: Yang
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.
authors.forename: Caroline
authors.initials: C
authors.lastname: Jacobson
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.
authors.forename: Graham
authors.initials: G
authors.lastname: Gardner
authors.affiliation: South Australian Research and Development Institute, 33 Flemington Street, Glenside, SA 5065, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Carmichael
authors.affiliation: Faculty of Veterinary Science, University of Melbourne, 250 Princes Highway, Werribee, Victoria 3030, Australia.
authors.forename: Angus J D
authors.initials: AJ
authors.lastname: Campbell
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia. Electronic address: Una.Ryan@murdoch.edu.au.
authors.forename: Una
authors.initials: U
authors.lastname: Ryan
mesh_terms: D000818:Animals; D001315:Australia / Q000453:epidemiology; D003048:Coccidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D016054:DNA, Protozoan / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D004539:Eimeria / Q000145:classification / Q000235:genetics / Q000502:physiology*; D005243:Feces / Q000469:parasitology; D008137:Longitudinal Studies; D008969:Molecular Sequence Data; D010270:Parasite Egg Count / Q000662:veterinary; D015995:Prevalence; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000592:standards / Q000662:veterinary; D012680:Sensitivity and Specificity; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000469:parasitology*
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S
keywords: 18S rRNA; E. ahsata; E. crandallis; E. cylindrica; E. ovinoidalis; E. weybridgensis; Eimeria; Lambs; qPCR