Molecular epidemiological analyses reveal extensive connectivity between Echinostoma revolutum (sensu stricto) populations across Eurasia and species richness of zoonotic echinostomatids in England

• Published in: PLOS ONE
• Main Authors: Enabulele, Egie E., Lawton, Scott P., Walker, Anthony J., Kirk, Ruth S.
• Other Authors: Pinto, Hudson Alves, Tertiary Education Trust Fund
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2023
• Subjects: Iceland
• Online Access: http://dx.doi.org/10.1371/journal.pone.0270672; https://dx.plos.org/10.1371/journal.pone.0270672

Echinostoma revolutum ( sensu stricto ) is a widely distributed member of the Echinostomatidae, a cosmopolitan family of digenetic trematodes with complex life cycles involving a wide range of definitive hosts, particularly aquatic birds. Integrative taxonomic studies, notably those utilising nad 1 barcoding, have been essential in discrimination of E . revolutum ( s . s .) within the ‘ Echinostoma revolutum ’ species complex and investigation of its molecular diversity. No studies, however, have focussed on factors affecting population genetic structure and connectivity of E . revolutum ( s . s .) in Eurasia. Here, we used morphology combined with nad 1 and cox 1 barcoding to determine the occurrence of E . revolutum ( s . s .) and its lymnaeid hosts in England for the first time, in addition to other echinostomatid species Echinoparyphium aconiatum , Echinoparyphium recurvatum and Hypoderaeum conoideum . Analysis of genetic diversity in E . revolutum ( s . s .) populations across Eurasia demonstrated haplotype sharing and gene flow, probably facilitated by migratory bird hosts. Neutrality and mismatch distribution analyses support possible recent demographic expansion of the Asian population of E . revolutum ( s . s .) ( nad 1 sequences from Bangladesh and Thailand) and stability in European ( nad 1 sequences from this study, Iceland and continental Europe) and Eurasian (combined data sets from Europe and Asia) populations with evidence of sub-population structure and selection processes. This study provides new molecular evidence for a panmictic population of E . revolutum ( s . s .) in Eurasia and phylogeographically expands the nad 1 database for identification of echinostomatids.