title: Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in dairy cattle in Ningxia, northwestern China.
abstract: BACKGROUND
  Cryptosporidium spp. and Giardia duodenalis are important gastrointestinal protists in humans and animals worldwide. In China, bovine cryptosporidiosis and giardiasis are of increasing concern because cattle are important reservoirs of these parasites, which have become potential threats to public health and to large numbers of cattle in recent years.
  
  
  RESULTS
  A total of 1366 fecal samples from the Ningxia Autonomous Region were examined. The overall infection rates for Cryptosporidium spp. and G. duodenalis were 1.61% and 2.12%, respectively. Cryptosporidium was only detected in preweaned calves and adults older than 2 years, whereas G. duodenalis was only detected in calves aged less than 11 months. Cryptosporidium spp. were characterized with a PCR-restriction fragment length polymorphism analysis and DNA sequence analysis of the small subunit rRNA gene. Three Cryptosporidium species were identified: C. parvum (n = 15) and C. bovis (n = 4) in preweaned calves, and C. andersoni (n = 4) in adults aged over 2 years. A DNA sequence analysis of the gp60 gene suggested that the 15 C. parvum isolates all belonged to subtype IIdA15G1. Twenty-nine G. duodenalis isolates were analyzed by DNA sequencing of the triosephosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes. Two G. duodenalis assemblages were identified, assemblages E (n = 15) and B (n = 4, one subtype B1 and three subtype B2) in preweaned calves, and assemblage E (n = 10) in 3-11-month-old calves.
  
  
  CONCLUSIONS
  The predominance of C. parvum detected in preweaned calves and the first identified subtype IIdA15G1 in dairy cattle, and the dominant G. duodenalis assemblage E in this study differed considerably from those found in Henan, Heilongjiang, and Shannxi Provinces. Our findings further confirm the dominance of C. parvum IId subtypes in China.
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. 344725562@qq.com.|International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou, 450002, China. 344725562@qq.com.
authors.forename: Jianying
authors.initials: J
authors.lastname: Huang
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. yuedaoyou@163.com.|International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou, 450002, China. yuedaoyou@163.com.
authors.forename: Daoyou
authors.initials: D
authors.lastname: Yue
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. 245105904@qq.com.|International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou, 450002, China. 245105904@qq.com.
authors.forename: Meng
authors.initials: M
authors.lastname: Qi
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. wrj-1978@163.com.|International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou, 450002, China. wrj-1978@163.com.
authors.forename: Rongjun
authors.initials: R
authors.lastname: Wang
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. 532949681@qq.com.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Zhao
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. lijunqiangcool@126.com.|International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou, 450002, China. lijunqiangcool@126.com.
authors.forename: Junqiang
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. 690053628@qq.com.|International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou, 450002, China. 690053628@qq.com.
authors.forename: Ke
authors.initials: K
authors.lastname: Shi
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China. vetdean@cau.edu.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. zhanglx8999@gmail.com.|International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou, 450002, China. zhanglx8999@gmail.com.
authors.forename: Longxian
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology*; D002681:China / Q000453:epidemiology; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000469:parasitology; D003458:Cryptosporidium; D016785:Cryptosporidium parvum; D016829:Giardia lamblia; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D015995:Prevalence