title: Genetic characterizations of Giardia duodenalis in sheep and goats in Heilongjiang Province, China and possibility of zoonotic transmission.
abstract: BACKGROUND
  Giardia duodenalis is a widespread intestinal protozoan of both humans and mammals. To date, few epidemiological studies have assessed the potential and importance of zoonotic transmission; and the human giardiasis burden attributable to G. duodenalis of animal origin is unclear. No information about occurrence and genotyping data of sheep and goat giardiasis is available in China. The aim of the present study was to determine prevalence and distribution of G. duodenalis in sheep and goats in Heilongjiang Province, China, and to characterize G. duodenalis isolates and assess the possibility of zoonotic transmission.
  
  
  RESULTS
  A total of 678 fecal specimens were collected from sheep and goats on six farms ranging in age from one month to four years in Heilongjiang Province, China. The average prevalence of G. duodenalis infection was 5.0% (34/678) by microscopy after Lugol's iodine staining, with 5.6% (30/539) for the sheep versus 2.9% (4/139) for the goats. Molecular analysis was conducted on 34 G. duodenalis isolates based on the triosephosphate isomerase (tpi) gene. 29 tpi gene sequences were successfully obtained and identified as assemblages A (n = 4), B (n = 2) and E (n = 23). High heterogeneity was observed within assemblage E at the tpi locus, with five novel subtypes found out of seven subtypes. Two subtypes of assemblage A were detected, including subtype AI (n = 3) and a novel subtype (designated as subtype AIV) (n = 1). Two assemblage B isolates were identical to each other in the tpi gene sequences.
  
  
  CONCLUSIONS
  This is the first report of G. duodenalis infections in sheep and goats in China. The present data revealed the unique endemicity on prevalence, distribution and genetic characterization of G. duodenalis in sheep and goats in Heilongjiang Province. The findings of assemblages A and B in sheep and goats implied the potential of zoonotic transmission.
authors.affiliation: Department of Parasitology, Harbin Medical University, Harbin, People's Republic of China.
authors.forename: Weizhe
authors.initials: W
authors.lastname: Zhang
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
authors.forename: Rongjun
authors.initials: R
authors.lastname: Wang
authors.forename: Aiqin
authors.initials: A
authors.lastname: Liu
authors.forename: Yujuan
authors.initials: Y
authors.lastname: Shen
authors.forename: Hong
authors.initials: H
authors.lastname: Ling
authors.forename: Jianping
authors.initials: J
authors.lastname: Cao
authors.forename: Fengkun
authors.initials: F
authors.lastname: Yang
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Zhang
authors.forename: Longxian
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D005243:Feces / Q000469:parasitology; D005838:Genotype; D016829:Giardia lamblia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission* / Q000662:veterinary*; D015511:Goat Diseases / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission; D006041:Goats / Q000469:parasitology; D015801:Helminth Proteins / Q000235:genetics; D008853:Microscopy / Q000379:methods; D008969:Molecular Sequence Data; D010274:Parasitology / Q000379:methods; D010802:Phylogeny; D015995:Prevalence; D017422:Sequence Analysis, DNA; D012756:Sheep / Q000469:parasitology; D012757:Sheep Diseases / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission; D014305:Triose-Phosphate Isomerase / Q000235:genetics; D015047:Zoonoses / Q000453:epidemiology / Q000635:transmission*
chemical_list: D018509:DNA, Helminth; D015801:Helminth Proteins; D014305:Triose-Phosphate Isomerase