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Licensed Unlicensed Requires Authentication Published by De Gruyter July 4, 2018

First molecular identification of an agent of diplostomiasis, Diplostomum pseudospathaceum (Niewiadomska 1984) in the United Kingdom and its genetic relationship with populations in Europe

Egie Elisha Enabulele, Agnes Ogheneruemu Awharitoma, Scott P. Lawton and Ruth S. Kirk
From the journal Acta Parasitologica


Trematode genus Diplostomum comprises of parasitic species which cause diplostomiasis, the ‘white eye’ disease in fish and heavy infection can result in mortality. The increasing availability of DNA sequences of accurately identified Diplostomum species on public data base presently enables the rapid identification of species from novel sequences. We report the first molecular evidence of the occurrence of D. pseudospathaceum in the United Kingdom. Two gene regions, nuclear internal transcribed spacer cluster (ITS1-5.8S-ITS2) and mitochondrial cytochrome c oxidase subunit 1 (cox1) of cercariae from infected aquatic snails, Lymnaea stagnalis collected in several locations in Southern England were sequenced. Phylogenetic analysis based on both sequenced genes revealed that the novel sequences were D. pseudospathaceum. Molecular diversity analysis of published D. pseudospathaceum cox1 sequences from seven countries in Europe and the novel sequences from the present study revealed high diversity, but low nucleotide divergence and a lack of gene differentiation between the populations. Haplotype network analysis depicted a star-like pattern and revealed a lack of geographic structure in the population. Fixation indices confirmed gene flow between populations and we suspect high levels of dispersal facilitated by highly mobile second intermediate (fish) and definitive (piscivorous birds) host may be driving gene flow between populations. Neutrality tests and mismatch distribution indicated recent population growth/expansion for D. pseudospathaceum in Europe.


The co-operation of the Four Seasons Hotel Hampshire, Godalming Angling Club and Nature England are appreciated for allowing snail sampling in the sites visited. This research was made possible by funding from the Tertiary Education Trust Fund of Nigeria for PhD studentship to the corresponding author at Kingston University London.


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Received: 2017-10-30
Revised: 2018-02-20
Accepted: 2018-03-02
Published Online: 2018-07-04
Published in Print: 2018-09-25

© 2018 W. Stefański Institute of Parasitology, PAS

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