Identification of Fasciola Species in Warm and Cool Western Provinces of Iran, Using Molecular and Morphometric Methods

Abstract

Background: Fascioliasis is a parasitic disease caused by Fasciola hepatica, Fasciola gigantica, and intermediate Fasciola, which is present in a wide variety of mammalian species, including humans, throughout the world. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method is one of the best methods for detecting Fasciola species in places where there are two types of Fasciola hepatica and Fasciola gigantica in domestic livestock. Methods: In this study, Fasciola worms were collected from slaughterhouses in five western provinces of Iran. Parasitic species were identified using morphological and molecular methods. A total of 756 livestocks (cattle and sheep) were studied, with 89 livers infected with adult Fasciola worms. 18 worms were morphometrically examined, and DNA from the eggs of these worms were extracted. A fragment of genome containing the ITS1,5.8S, ITS2 gene was amplified and utilized by TasI enzyme, and PCR-RFLP was performed on amplified parts. Findings: A total of 178 adult Fasciola worm were isolated from infected cattle and sheep livers. During the spring 2017, the highest and the lowest levels of contamination were reported in Ilam Province (sheep, 28.53%) and Kermanshah Province (sheep, 7.9%), Respectively. In Fasciola hepatica, TasI enzyme produced three fragments of 427, 360 and 117 base pair (bp), and for Fasciola gigantica, it produced three fragments of 360, 220, and 117 bp on 1.5% agarose gel. Conclusion: According to the study, microscopic measurements can be sufficient for microscopic characterization of Fasciola species, but the PCR-RFLP method using TasI enzyme is simpler, faster, and more accurate. The use of PCR-RFLP method and ITS genetic marker is very suitable for identification of Fasciola species.

Keywords

• fasciola
• fasciola hepatica
• polymerase chain reaction
• restriction fragment length polymorphism