title: Cryptosporidium cuniculus and Giardia duodenalis in rabbits: genetic diversity and possible zoonotic transmission.
abstract: BACKGROUND
  Cryptosporidium and Giardia are the two important zoonotic pathogens causing diarrhea of humans and animals worldwide. Considering the human cryptosporidiosis outbreak and sporadic cases caused by C. cuniculus, the important public health significance of G. duodenalis and little obtained information regarding rabbit infected with Cryptosporidium and Giardia in China, the aim of this study is to determine the prevalence and molecularly characterize Cryptosporidium and Giardia in rabbits in Heilongjiang Province, China.
  
  
  RESULTS
  378 fecal samples were obtained from rabbits in Heilongjiang Province. Cryptosporidium oocysts and Giardia cysts were detected using Sheather's sugar flotation technique and Lugol's iodine stain method, respectively. The infection rates of Cryptosporidium and Giardia were 2.38% (9/378) and 7.41% (28/378), respectively. Genotyping of Cryptosporidium spp. was done by DNA sequencing of the small subunit rRNA (SSU rRNA) gene and all the nine isolates were identified as Cryptosporidium cuniculus. The nine isolates were further subtyped using the 60-kDa glycoprotein (gp60) gene and two subtypes were detected, including VbA32 (n = 3) and a new subtype VbA21 (n = 6). G. duodenalis genotypes and subtypes were identified by sequence analysis of the triosephosphate isomerase (TPI) gene. The assemblage B (belonging to eight different subtypes B-I to B-VIII) was found in 28 G. duodenalis-positive samples.
  
  
  CONCLUSIONS
  The rabbits have been infected with Cryptosporidium and Giardia in Heilongjiang Province. The results show that the rabbits pose a threat to human health in the studied areas. Genotypes and subgenotypes of C. cuniculus and G. duodenalis in this study might present the endemic genetic characterization of population structure of the two parasites.
authors.affiliation: Department of Parasitology, Harbin Medical University, Harbin, Heilongjiang, China.
authors.forename: Weizhe
authors.initials: W
authors.lastname: Zhang
authors.forename: Yujuan
authors.initials: Y
authors.lastname: Shen
authors.forename: Rongjun
authors.initials: R
authors.lastname: Wang
authors.forename: Aiqin
authors.initials: A
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Ling
authors.forename: Yihong
authors.initials: Y
authors.lastname: Li
authors.forename: Jianping
authors.initials: J
authors.lastname: Cao
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Shu
authors.forename: Longxian
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001483:Base Sequence; D002681:China; D003458:Cryptosporidium / Q000145:classification / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D016829:Giardia lamblia / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D011817:Rabbits; D014305:Triose-Phosphate Isomerase / Q000235:genetics; D015047:Zoonoses / Q000469:parasitology* / Q000635:transmission*
chemical_list: D014305:Triose-Phosphate Isomerase