title: Seroprevalence, Isolation, Genotyping, and Pathogenicity ofToxoplasma gondiiStrains from Sheep in China.
abstract: Toxoplasma gondiiis an important cause of reproductive failure in small ruminants that also poses a risk to consumers who consume undercooked meat. However, little is known about sheep toxoplasmosis in China for the world. Therefore, this study was conducted to assess the prevalence ofT. gondiiinfection in sheep from China, to isolateT. gondiivia bioassay in mice and to evaluate the virulence of the isolatedT. gondiibased on vero cell invasion and mice. A total of 840 samples (304 unfrozen hearts and 536 sera) from sheep in China were collected from 2014 to 2016. Heart samples (n= 36) ofT. gondiiseropositive sheep (MAT, ≥25) were bioassayed in mice individually. DNA derived from cell cultured tachyzoites of the isolatedT. gondiiwas characterized by PCR-RFLP of 10 loci (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The virulence of theT. gondiiwas evaluated based on the mortality and encystation in mice, as well as their growth characteristics in cell culture. Antibodies toT. gondiiwere found in 174 of 840 (20.71%, 304 hearts juice and 536 sera) sheep by the modified agglutination test (cut-off 1:25). ViableT. gondiiwas isolated from the hearts of two of 36 seropositive sheep hearts. Both genotypes of the sheep heart isolates were ToxoDB#9. The virulence of the two ToxoDB#9 isolations varied significantly. To the best of our knowledge, this is the first report of isolation of ToxoDB#9 strain ofT. gondiifrom sheep in China.
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University Zhengzhou, China.
authors.forename: YuRong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University Zhengzhou, China.
authors.forename: YongJie
authors.initials: Y
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China.
authors.forename: QiuXia
authors.initials: Q
authors.lastname: Yao
authors.affiliation: Center for Animal Disease Control and Prevention of Henan Province Zhengzhou, China.
authors.forename: YingHua
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University Zhengzhou, China.
authors.forename: YaoYao
authors.initials: Y
authors.lastname: Lu
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University Zhengzhou, China.
authors.forename: HongDe
authors.initials: H
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China.
authors.forename: XingQuan
authors.initials: X
authors.lastname: Zhu
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University Zhengzhou, China.
authors.forename: LongXian
authors.initials: L
authors.lastname: Zhang
keywords: China; Toxoplasma gondii; genotype; isolation; seroepidemiology; sheep; virulence