Echinococcus genomes: new information to apply to molecular epidemiology and echinococcosis control

KAMENETZKY, L.

Congreso; Congresso da Sociedade Brasileira de Medicina Tropical; 2019

The parasite Echinococcus  spp. is  the causative agent ofechinococcosis, a worldwide chronic zoonosis affecting humans as well asdomestic and wild mammals. In South America six specieswere found: E. granulosus sensu stricto, E. canadensis, E. ortleppi, E.oligarthrus and E . vogeli.  E.granulosus s. s.  accounts for most ofthe global burden of human and livestock cases. Also, E. canadensis plays a significantrole in human cystic echinococcosis particularly in Argentina, 36.1%  of the humancases are caused by E. canadensis. We sequenced  the completegenome of E. canadensis  and compared itwith the complete genomes from E. multilocularis, E.granulosus (G1) and E. canadensis (G7). Genomicanalyses using whole genome data of three Echinococcusspecies not only confirmed the status of E.canadensis (G7) as a separate species but also demonstrated a highnucleotide sequences divergence in relation to E. granulosus (G1). Comparative genomics revealed that there aremore single nucleotide polymorphisms (SNPs) between E. canadensis (G7) and E.granulosus (G1) than between E.canadensis (G7) and E. multilocularis.This result was unexpected since E.canadensis (G7) and E. granulosus(G1) were considered to belong to the species complex E. granulosus sensu lato. At present there is no unequivocaltaxonomic classification of Echinococcusspecies therefore additional cestode genomes such as Echinococcus oligarthrus are been sequenced to resolve Echinococcusphylogeny. Additionally, relevant genomic structures involved in gene expressionregulation were characterized among the three Echinococcus species.