High intraspecific variability of Echinococcus granulosus sensu stricto in Chile

Abstract

Echinococcus granulosus sensu stricto is the major cause of cystic echinococcosis in most human and animal cases in the world and the most widespread species within the E. granulosus sensu lato complex. E. granulosus s.s. remains endemic in South America together with other species of the Echinococcus genus, especially in some areas in Argentina, Brazil, Chile and Peru. Except for a single human case caused by E. canadensis (G6) described in the literature, only E. granulosus s.s. has been found in the Chilean territory. In the current study 1609bp of the cox1 gene from 69 Chilean isolates of E. granulosus s.s. from humans and animals were analysed. In total, 26 cox1 haplotypes were found, including the widespread haplotype EG01 (22 isolates) and also EGp1 (5), EgRUS7 (1), EgAus02 (1) and EgAus03 (2). Twenty-one different haplotype not previously described were identified from 38 Chilean isolates designated EgCL1-EgCL21. Previous work had described low variability of E. granulosus s.s. in South America, based on isolates from Peru. Results obtained in this work challenge the previously described idea of the low diversity of the parasite in South America, and warrant future investigation on the origin and spread of the parasite in the continent after the Spanish arrival.

Genetic variation of Echinococcus spp. in yaks and sheep in the Tibet Autonomous Region of China based on mitochondrial DNA

“…population in the Tibetan plateau [10, 13, 31]. The low nucleotide diversity among E. granulosus ( s.s. ) in the present study has also been previously observed in the Qinghai-Tibet region and other parts of China [13, 31] as well as from outside China [32, 33], supporting the demographical expansion of the group. Also, the low F ST value between the intermediate host populations suggests that both populations are genetically undifferentiated, indicating gene flow and alleles sharing between the subpopulations of E. granulosus ( s.s. ) and possibly with the overall population in the region which is plausible considering that both intermediate hosts utilized the same environment with no geographical barrier and are exposed to similar risk factors like contamination of pastures with faeces of infected dogs.…”

Echinococcus granulosus sensu stricto, Echinococcus ortleppi; and E. intermedius (G7) are present in Bolivia

“…From the 30 isolates identified as E. granulosus s.s. in the cyst samples, 20 of them were recognized as the cox1 haplotype Eg01 (Accession number JQ250806) (Table 1). The cox1 haplotype EgCL03 (KX227118) (Alvarez Rojas et al ., 2017) was identified in a single sequence in this study (Table 1). The remainder 9 sequences identified as E. granulosus s.s. do not share 100% homology with any sequence deposited in GenBank and they are named here as EgBol1-EgBol7 (Accession numbers: MT072973-MT072979) (Table 1).…”

“…ortleppi has been described in Argentina, Brazil, Chile and Uruguay; E. intermedius (G6) has been found in Argentina, Chile and Peru. And E. intermedius (G7) has been isolated in Argentina, Brazil and Peru (Rosenzvit et al ., 1999; Kamenetzky et al ., 2000; Kamenetzky et al ., 2002; Guarnera et al ., 2004; Badaraco et al ., 2008; Manterola et al ., 2008; Santivañez et al ., 2008; Moro et al ., 2009; Sánchez et al ., 2010; Schneider et al ., 2010; Soriano et al ., 2010; de la Rue et al ., 2011; Balbinotti et al ., 2012; Sánchez et al ., 2012; Armua-Fernandez et al ., 2014; Espinoza et al ., 2014; Monteiro et al ., 2014; Cucher et al ., 2016; Alvarez Rojas et al ., 2017; Deplazes et al ., 2017; Corrêa et al ., 2018) and more recently, for the first time in Ecuador (Ramos-Sarmiento and Chiluisa-Utreras, 2020). In the case of Bolivia, this data is limited to two human cases reported as E .…”

First description of Echinococcus ortleppi and cystic echinococcosis infection status in Chile

“…granulosus s.s. has been reported in intermediate hosts in Chile: G1 in cattle [ 6 ] and humans [ 5 ]; G3 in cattle [ 6 ]; a number of haplotypes of E . granulosus s.s. [ 8 ] and E . canadensis G6 in a single human isolate [ 5 ].…”

“…s . has been reported in humans and cattle [ 5 – 8 ], E . canadensis (G6) was reported in 1 human sample [ 5 ]; other genotypes or species have never been described so far.…”