title: Genotypic characterization and species identification of Fasciola spp. with implications regarding the isolates infecting goats in Vietnam.
abstract: Ribosomal RNA sequences (361 or 362bp) of the second internal transcribed spacer 2 (ITS-2) and a portion of mitochondrial cox1 (423bp) for Fasciola spp. obtained from specimens collected in indigenous and hybrid goats and sheep in Vietnam were characterized for genotypic status and hybridization/introgression. Alignment of 48 ITS-2 sequences (also those from goats and sheep in this study) indicates that F. gigantica and F. hepatica differ typically from each other at seven sites whereas one of these is a distinguishing deletion (T) at the 327th position in F. gigantica relative to F. hepatica. The isolates from the mountainous goats in the North of Vietnam (Yen Bai province) showed the ITS-2 composition relatively identical to that of F. hepatica. The ITS-2 sequences from populations of Fasciola isolates in goats had probably experienced introgression/hybridization as reported previously in other ruminants and humans. All Vietnamese goat-of-origin specimens had high pairwise percentage of mitochondrial cox1 sequences to F. gigantica (97-100%), and very low identity to F. hepatica (91-93%), suggesting their maternal linkage to be traced to F. gigantica. The presence of hybrid and/or introgressed populations of liver flukes bearing genetic material from both F. hepatica and F. gigantica in the goats/sheep in Vietnam, regardless of indigenous or imported hosts, appears to be the first demonstration from a tropical country.
authors.affiliation: National Institute of Veterinary Research, Hanoi, Viet Nam.
authors.forename: Thanh Giang Thi
authors.initials: TG
authors.lastname: Nguyen
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van De
authors.forename: Jozef
authors.initials: J
authors.lastname: Vercruysse
authors.forename: Pierre
authors.initials: P
authors.lastname: Dorny
authors.forename: Thanh Hoa
authors.initials: TH
authors.lastname: Le
mesh_terms: D000818:Animals; D002020:Buffaloes; D002417:Cattle; D051545:Cyclooxygenase 1 / Q000235:genetics; D018509:DNA, Helminth / Q000737:chemistry / Q000302:isolation & purification; D021901:DNA, Intergenic / Q000737:chemistry; D005209:Fasciola / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005211:Fascioliasis / Q000469:parasitology / Q000662:veterinary*; D005819:Genetic Markers; D005838:Genotype; D015511:Goat Diseases / Q000469:parasitology*; D006041:Goats; D006801:Humans; D010802:Phylogeny; D016415:Sequence Alignment / Q000662:veterinary; D012756:Sheep; D014744:Vietnam
chemical_list: D018509:DNA, Helminth; D021901:DNA, Intergenic; D005819:Genetic Markers; D051545:Cyclooxygenase 1