Molecular phylogenetic and genetic variability of <i>Fasciola gigantica</i> in Kermanshah province, western Iran with an overview to understand haplotypes distribution in Asia and Africa

Abstract

Over the last decade, diagnostic tools to detect and differentiate <em>Fasciola</em> species have improved, but our understanding of the distribution of haplotypes and population structure of this parasite is less clear. This study was designed to survey this gap in the <em>F. gigantica</em> epidemiology in Kermanshah province, western Iran from 2015 to 2017.Sixty-eight <em>Fasciola </em>isolates were collected from slaughterhouses from this province. We evaluated the PCR-RFLP assay of the ITS1 genes for the identification of <em>Fasciola</em> species using the RsaI enzyme. After <em>Fasciola</em> species identification, the partial sequence of mitochondrial NADH dehydrogenase subunit 1 (ND1) gene of <em>F. gigantica</em> was used for subsequent construction of the phylogenetic tree and network analysis.Based on the PCR-PRFLP profile, one (6.25%) of sheep isolates and 19 (39.60%) of cattle isolates were detected as <em>F. gigantica</em>, whereas 93.75% of sheep isolates, 60.40% of cattle isolates and all of the goat isolates were <em>F. hepatica</em>. In the 20 analyzed flukes, five ND1 haplotypes were detected. Statistically significant genetic differentiation was demonstrated between the Iran population and all the other populations. Evidence is presented for the existence of two well-separated populations: African and West Asian <em>gigantica</em> flukes and East Asian <em>gigantica</em> flukes.Genetic relationships among haplotypes were associated with geographical divisions. Also, our results have heightened our knowledge about the genetic diversity of <em>F. gigantic</em>, providing the first evidence for the existence of two well-separated populations of this parasite.