Genetic Characterization of Fasciola Isolates from West Azerbaijan Province Iran Based on ITS1 and ITS2 Sequence of Ribosomal DNA

Fascioliasis, caused by Fasciola hepatica and F. gigantica, has medical
and economic importance in the world. Molecular approaches comparing traditional methods using for identification and characterization of Fasciola spp. are
precise and reliable. The aims of current study were molecular characterization of
Fasciola spp. in West Azerbaijan Province, Iran and then comparative analysis of
them using GenBank sequences.
Methods: A total number of 580 isolates were collected from different hosts in
five cities of West Azerbaijan Province, in 2014 from 90 slaughtered cattle (n=50)
and sheep (n=40). After morphological identification and DNA extraction, designing specific primer were used to amplification of ITS1, 5.8s and ITS2 regions,
50 samples were conducted to sequence, randomly.
Result: Using morphometric characters 99.14% and 0.86% of isolates identified
as F. hepatica and F. gigantica, respectively. PCR amplification of 1081 bp fragment
and sequencing result showed 100% similarity with F. hepatica in ITS1 (428 bp),
5.8s (158 bp), and ITS2 (366 bp) regions. Sequence comparison among current
study sequences and GenBank data showed 98% identity with 11 nucleotide
mismatches. However, in phylogenetic tree F. hepatica sequences of West Azerbaijan Province, Iran, were in a close relationship with Iranian, Asian, and African
isolates.
Conclusions: Only F. hepatica species is distributed among sheep and cattle in
West Azerbaijan Province Iran. However, 5 and 6 bp variation in ITS1 and ITS2
regions, respectively, is not enough to separate of Fasciola spp. Therefore, more
studies are essential for designing new molecular markers to correct species identification.