Molecular identification for small liver fluke in duck isolated in Binh Dinh province using nuclear genome (ITS-2)

Abstract

A total of 120 small liver flukes in ducks were collected in Binh Dinh province, and their DNA were extracted. A region of nucleotide of ITS2 of the small liver fluke was amplified by PCR. This nucleotide sequence was compared with those in the Genbank through BLAST programme. The comparison result indicated that high similarity level of nucleotide of ITS2 of the isolated small liver flukes in ducks in Binh Dinh province and those of others including: O. viverrini, O. lobatus, O. felineus and C. sinensis was identified, the percentages of the changed nucleotides were 0.5%, 1.42%, 3.42% and 2.3%, respectively. The phylogenetic tree analysis of the ITS2 gene showed that the liver fluke in duck in Binh Dinh province belonged to Opisthorchiidae family, and had a close phylogenetic relationship to O. viverrini, O. labotus. The results of the morphological examinations and the nucleotide sequence analysis of ITS2 illustrated that all morphological features of the small liver fluke in duck in Binh Dinh province were obviously compatible with Opisthorchiidae family, Opisthorchis genus and O. parageminus species. That is a small liver fluke species parasiting in duck in northern provinces, Viet Nam and it was named by Oshmarin in 1970.