Molecular characterization of Echinococcus isolates of cervid origin from Finland and Sweden

Abstract

The species Echinococcus granulosus is made up of several genotypic strain groups, whose taxonomical classification is still undetermined. Genotypes in the cervid-wolf life-cycle are poorly known, especially in Europe. In this study, 33 Echinococcus isolates from cervids from Finland and Sweden were characterized using mitochondrial ND1 gene sequencing. In addition, phylogenetic analysis of E. granulosus strains using the mitochondrial ATP6, ND1, ND3 and CO1 genes was performed using maximum likelihood, neighbour-joining and maximum parsimony methods. The Finnish and Swedish cervid isolates were found to represent the genotype G10. In the phylogenetic analyses, the camel (G6), pig (G7), cervid (G8) and Fennoscandian cervid (G10) strains clustered in a well-supported monophyletic group. This group differed clearly from the common sheep (G1) and horse (G4, 'E. equinus') strains, but was closely related to the cattle strain (G5, 'E. ortleppi'). Our results support the previous studies suggesting that the genotypes G6-10 should be separated from the species E. granulosus sensu stricto. However, additional morphological studies are needed, and the relationship to the cattle strain ('E. ortleppi') should be thoroughly evaluated before a final decision of the taxonomical status of the G6-10 group can be made.

Prevalence of cystic echinococcosis in pigs from Slovakia, with evaluation of size, fertility and number of hydatid cysts

“…in Argentina contributes for up to 37 -44 % of human CE cases, despite the presence of highly infective sheep strains (G1, G2 genotypes) in the country (Rosenzvit et al, 1999;Guarnera et al, 2004). The close relationships among camel (G6), pig (G7) and G8/G10 (cervid) strains were demonstrated by recent genetic studies (Lavikainen et al, 2006;Nakao et al, 2007;Moks et al, 2008). If the species categorization for this cluster is taxonomically verified, in terms of time priority it is named E. canadensis according to the former designation of cervid strain (Webster and Cameron, 1961).…”

Phylogenetic Pattern, Evolutionary Processes and Species Delimitation in the Genus Echinococcus

“…Le et al, 2002;McManus et al, 2002;Obwaller et al, 2004;Lavikainen et al, 2003Lavikainen et al, , 2006Thompson et al, 2006;Nakao et al, 2007Nakao et al, , 2013bHüttner et al, 2008;Moks et al, 2008) and nuclear DNA sequences (e.g. Lavikainen et al, 2003;Bart et al, 2006;Saarma et al, 2009;Knapp et al, 2011).…”

Characterization of Taenia madoquae and Taenia regis from carnivores in Kenya using genetic markers in nuclear and mitochondrial DNA, and their relationships with other selected taeniids

“…Importantly, the present findings also provide a 'stepping stone' for future work on establishing the systematic relationships of some of the lesser-known taeniid cestodes [11] based on partial or, preferably, whole mitochondrial genome sequence data sets (cf. [15] and [44]), as has been undertaken comprehensively for members of the genus Echinococcus (e.g., [15], [35], [45] and [46].…”