Molecular identification of the zoonotic parasites Contracaecum spp. and Anisakis pegreffii (Nematoda: Anisakidae) isolated from Mesopotamichthys sharpeyi and Barbus grypus in the Shadegan Marsh of Khuzestan Province

The family of Anisakidea (Anisakis and Contracaecum) includes zoonotic parasitic nematodes that have worldwide distribution. Two hundreds Anisakis and Contracaecum sp. nematode samples were collected from the intestine of Mesopotamichthys sharpeyi and Barbus grypus caught from Shadegan Wetland, where known as an important international wetland in Iran with a rich biodiversity. After extraction of the genomic DNA, PCR was used to amplify the entire ITS fragment with primers NC5-NC2. PCR products were fractionated by agarose gel electrophoresis prior to purify using gel extraction kit. The purified DNA was sequenced by an Applied Biosystems DNA sequenced in both directions. In order to compare the obtained sequence data with similar sequences from other nematodes, target sequence data were retrieved from the GenBank. The overall prevalence of Anisakis and Contracaecum in the studied fish from Shadegan Wetland was 6% and 9% in Mesopotamichthys sharpeyi and 4% and 6% in Barbus grypus, respectively. All nematodes were identified as Anisakis pegreffii and Contracaecum rudolphii based on the phylogenetic tree and genetic distance. This is the first time to report the distribution of A. pegreffii and C. rudolphii in Mesopotamichthys sharpeyi and Barbus grypus in Shadegan Wetland. Based on the results, the danger of zoonotic anisakid nematodes, including A. pegreffii and C. rudolphii in the studied area is very low.