title: [Geographic distribution and gene sequencing of Paragonimus westermani in some areas of Guangdong Province].
abstract: OBJECTIVE
  To investigate the current distribution of Paragonimus westermani in Guangdong Province.
  
  
  METHODS
  Snails and crabs collected from mountain streams in regional survey sites were dissected to detect cercarial and metacercarial infections of P. westermani. Domestic cats and dogs artificially infected with the collected metacercariae were also dissected to detect adult worms of P. westermani. The COI and ITS2 gene sequences of those adult worms were compared with those of known Paragonimus specimen deposited in the GenBank.
  
  
  RESULTS
  All of the first intermediate hosts in five survey sites of Liangkou, Nankun, Mountain, Dadong, Muxi, Guowu, were identified as Semisulcospira libertina, whose cercariae infection rates were 0.33%, 0.15%, 0.058%, 0.10%, and 0.05%, respectively; the second intermediate hosts in above five sites were all identified as Sinopotamon denticulatum, whose metacercariae infection rates were 100%, 100%, 38.09%, 55.36%, and 65.26%, respectively. The numbers of metacercariae in the five sites were 79.4, 105.66, 9.16, 16.18, and 15.6 per positive crab, respectively, and 11.12, 7.87, 0.58, 0.69, and 0.85 per gram of crab, respectively. All the metacercariae were identical to those of P. westermani. Adult worms and eggs of P. westermani were found in both reservoir hosts of domestic cats and dogs infected artificially. By comparing the COI genes of five representative samples from each survey site with that of Paragonimus #AF219379.21, AF540958.1 from GenBank, we found out the homology to be 99%, 99%, 99%, 98%, and 99%, respectively. In addition, a comparison of the ITS2 gene sequences between the above five samples and Paragonimus #DQ836243.1, DQ351845.1, AB354217.1 from GenBank revealed 98%, 99%, 98%, 98%, and 98% gene homology, respectively.
  
  
  CONCLUSIONS
  Two ultra-high and three high endemic areas of P. westermani are discovered in Guangdong Province. No obvious differences were found among the types of P. westermani in the above five endemic areas.
authors.affiliation: Vocational College of Health Project, Guangzhou Medical College, Guangzhou 510925, China.
authors.forename: Yu-Yun
authors.initials: YY
authors.lastname: Lu
authors.forename: Qiao
authors.initials: Q
authors.lastname: Liu
authors.forename: Gao-Xing
authors.initials: GX
authors.lastname: Tang
authors.forename: Hao-Xian
authors.initials: HX
authors.lastname: Shen
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Zhong
authors.forename: Quan-Chao
authors.initials: QC
authors.lastname: Xie
authors.forename: Guang-Hua
authors.initials: GH
authors.lastname: Fu
authors.forename: Yu-Lian
authors.initials: YL
authors.lastname: Chen
authors.forename: Hao-Bin
authors.initials: HB
authors.lastname: Li
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: He
mesh_terms: D000818:Animals; D001483:Base Sequence; D003386:Brachyura / Q000469:parasitology; D002415:Cats; D002681:China; D004197:Disease Reservoirs / Q000469:parasitology*; D004285:Dogs; D005843:Geography; D015801:Helminth Proteins / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010237:Paragonimiasis / Q000469:parasitology*; D048492:Paragonimus westermani / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D012908:Snails / Q000469:parasitology
chemical_list: D015801:Helminth Proteins