Variation in Echinococcus: Towards a Taxonomic Revision of the Genus

Biology and Systematics of Echinococcus

“…These informal groupings were retained for many years but with the advent of molecular characterization they were shown to be genetically distinct (Thompson and McManus, 2001). PCR-based techniques using a variety of genetic loci, and sequencing of nuclear and mitochondrial DNA, coupled with molecular epidemiological studies in endemic areas, confirmed the genetic and morphological distinctness of the host-adapted strains and revealed phylogenetic relationships which support a robust, meaningful taxonomy based on a previously documented nomenclature (Table 2; Bowles et al, 1994;Cruz-Reyes et al, 2007;Harandi et al, 2002;Huttner et al, 2009;Jenkins et al, 2005Lavikainen et al, 2003Moks et al, 2008;Nakao et al, 2013;Pednekar et al, 2009;Romig et al, 2006Romig et al, , 2015Saarma et al, 2009;Thompson et al, 1995Thompson et al, , 2006Thompson, 2001Thompson, , 2008Thompson and McManus, 2002;Tigre et al, 2016). Interestingly, the nomenclature used for these 'species' conforms to that proposed by observational parasitologists in the 1920se60s, before molecular tools were available to confirm and support their morphological descriptions and epidemiological observations Thompson and McManus, 2002;Thompson, 2008).…”

Echinococcus as a model system: biology and epidemiology

“…The economic impact and public health significance of cystic culture (Smyth, 1946(Smyth, , 1950, he turned his attention to cus (see Smyth, 1990) (Smyth et al, 1966 andreviewed in Smyth and132 Davies, 1974a;Howell and Smyth, 1995) and evolutionary biology (Smyth, 1969;Smyth et al, 1966), and 136 which have influenced research and theoretical understanding far 137 beyond parasitology (Thompson and Lymbery, 2013 Thompson et al (1995), Thompson and McManus (2002), Jenkins et al (2005a), Thompson (2008), and Carmena and Cardona (2014). .…”

“…In terms of Echinococcus, the observation of physiological differ- Echinococcus of horse origin (Williams and Sweatman, 1963 (Table 1) does not appear to be infective to humans (Thompson 469 and Lymbery, , 1991 Thompson et al, 1995;Thompson, 2008 (Gemmell, 1990). Domestically, the parasite spread rapidly 529 through sheep and dog populations (Gemmell, 1990) Australia (Durie and Riek, 1952), a situation that prevails today 583 (Jenkins and Morris, 2003 Section 3.7.1) into urban areas this is no longer the case.…”

The molecular epidemiology of parasite infections: Tools and applications

“…Organisms following the same evolutionary trajectory should be monophyletic (derived from the same ancestral taxon) and exclusive (more closely related to each other than they are to any individuals outside the group) [94]. The morphologically defined species Echinococcus granulosus, for example, has now been split into a number of different species, because phylogenies based on mtDNA sequence data indicate that strains of E. granulosus are not monophyletic [95,96].…”

“…could interact. These questions have subsequently been resolved with the advent of reliable, robust and reproducible molecular tools which have not only supported the early taxonomy, but also demonstrated the distinctness of transmission cycles and the potential for interaction, particularly with respect to zoonotic transmission [95,103,106]. Importantly, these molecular epidemiological studies have given confidence to the morphological characters used for species discrimination which now offer a simple, cost effective means of parasite identification in endemic foci where the application of molecular tools may not be practical or cost-effective [107,108].…”