title: Prevalence and multilocus genotyping of Giardia duodenalis in dairy calves in Xinjiang, Northwestern China.
abstract: Giardia duodenalis is an important protozoan parasite. It is an established zoonotic pathogen and dairy calves have been implicated as one of the most important sources of human infection. This study was conducted to assess the prevalence and multilocus genotyping of G. duodenalis in dairy calves in the Xinjiang Uyghur Autonomous Region, northwestern China.
  
  
  
  A total of 514 fresh fecal samples were randomly collected from dairy calves in 15 farms in Xinjiang, 13.4 % (69/514) tested positive for G. duodenalis by polymerase chain reaction (PCR) detection of the small subunit ribosomal RNA (SSU rRNA) gene, with the prevalence being 9.7 % (23/237) and 16.6 % (46/277) in pre- and post-weaned calves, respectively. Sequence analysis of the SSU rRNA gene predominantly detected G. duodenalis assemblage E (92.8 %, 64/69), whereas assemblage A was identified in five samples (7.2 %, 5/69). All G. duodenalis-positive samples were assayed with PCR followed by sequencing at β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes, and 29, 37 and 33 sequences were obtained, respectively. The presence of mixed G. duodenalis assemblage A and E was detected in only one sample. Multilocus genotyping yielded 15 multilocus genotypes (MLGs), one new assemblage A MLG, and 14 assemblage E MLGs. All assemblage E MLGs identified here differed genetically from those of cattle from Henan Province, Central China.
  
  
  
  Our data indicate that G. duodenalis is a common parasite in dairy calves in Xinjiang, China, and calves appear to be a reservoir of G. duodenalis that is infectious to humans. The differences in the distribution of G. duodenalis assemblage E MLGs from cattle were likely to be because of geographical segregation.
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, People's Republic of China.|College of Animal Science, Tarim University, 1487 Tarim Road, Alar, 843300, People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Qi
authors.affiliation: Department of Animal Science, Henan Vocational College of Agriculture, Zhongmu, 451450, People's Republic of China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Animal Science, Tarim University, 1487 Tarim Road, Alar, 843300, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jing
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, People's Republic of China.
authors.forename: Rongjun
authors.initials: R
authors.lastname: Wang
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, People's Republic of China.
authors.forename: Fuchun
authors.initials: F
authors.lastname: Jian
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, People's Republic of China.
authors.forename: Changshen
authors.initials: C
authors.lastname: Ning
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, People's Republic of China. zhanglx8999@henau.edu.cn.
authors.forename: Longxian
authors.identifier: 0000-0002-5706-131X
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000469:parasitology*; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005838:Genotype; D060005:Genotyping Techniques; D016829:Giardia lamblia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D017720:Molecular Epidemiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D015995:Prevalence; D015800:Protozoan Proteins / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D015800:Protozoan Proteins; D012337:RNA, Ribosomal, 18S
keywords: Dairy calves; Genotyping; Giardia duodenalis; Prevalence