Periparturient transmission of Cryptosporidium xiaoi from ewes to lambs
State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China Veterinary Parasitology
(Impact Factor: 2.46).
07/2013; 197(3-4). DOI: 10.1016/j.vetpar.2013.07.021
The mechanism for the maintenance of Cryptosporidium infection in sheep between yearly lambing periods is not clear. Previously, periparturient shedding of oocysts as the result of stress from lambing was suspected to be a mechanism for the initiation of Cryptosporidium infection in lambs, but this has never been verified by genotyping studies. In this study, fecal specimens from four age groups of sheep in Inner Mongolia, China were examined for Cryptosporidium spp. by PCR-restricted fragment length polymorphism and sequence analyses of the small subunit (SSU) rRNA gene, including 59 ewes 1 week before parturition, 154 ewes at parturition, 87 lambs of 3-4 weeks, and 75 lambs of 15-16 weeks. The Cryptosporidium infection rate in ewes at parturition (7.8%) was significantly higher than at 1 week before parturition (1.7%). Higher infection rates were found in lambs (18.4% and 26.7% for 3-4-week-old and 15-16-week-old lambs, respectively). Most (10/13) Cryptosporidium-positive ewes were shedding Cryptosporidium xiaoi, which was also the dominant species (15/16) in neonatal lambs of 3-4 weeks in age (15/16). The less common species in ewes, Cryptosporidium ubiquitum, was not found in lambs of 3-4 weeks but was the dominant species (14/20) in lambs of 15-16 weeks. The major zoonotic Cryptosporidium species, C. parvum (of the IIaA15G2R1 subtype), was only found in one lamb. These data support the occurrence of periparturient transmission of Cryptosporidium spp., especially C. xiaoi, from ewes to lambs.
Available from: Rongchang Yang
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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 3,412 faecal samples were collected from approximately 1,182 lambs across the 4 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 × 106 and the median was 3.2 × 104 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.
Available from: Alan Lymbery
Available from: Melanie Koinari
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ABSTRACT: Species of Cryptosporidium are extensively recognised as pathogens of domesticated livestock and poultry, companion animals, wildlife, and are a threat to public health. Little is known of the prevalence of Cryptosporidium spp. in humans, domesticated animals or wildlife in Papua New Guinea (PNG). The aim of the present study was to screen goats and sheep for Cryptosporidium using molecular tools. A total of 504 faecal samples were collected from sheep (n=276) and goats (n=228) in village, government and institutional farms in PNG. Samples were screened by nested PCR and genotyped at the 18S rRNA and at the 60 kDa glycoprotein (gp60) loci. The overall prevalences were 2.2% for sheep (6/278) and 4.4% (10/228) for goats. The species/genotypes identified were C. hominis (subtype IdA15G1) in goats (n=6), C. parvum (subtypes IIaA15G2R1and IIaA19G4R1) in sheep (n=4) and in goats (n=2), C. andersoni (n=1) and C. scrofarum (n=1) in sheep, C. xiao (n=1) and Cryptosporidium rat genotype II (n=1) in goats. This is the first report of Cryptosporidium spp. identified in sheep and goats in PNG. Identification of Cryptosporidium in livestock warrants better care of farm animals to avoid contamination and illness in vulnerable population. The detection of zoonotic Cryptosporidium in livestock suggests these animals may serve as reservoirs for human infection.
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