New morphological, biological, and molecular insights into Taenia talicei (Cestoda: Taeniidae), adding the dog (Canis lupus familiaris) and Andean fox (Lycalopex culpaeus) as definitive hosts, and new records of intermediate hosts in Peru

Abstract

Taenia talicei is a cestode endemic to South America that was originally described based on its metacestodes. The adult strobilus was described after being obtained through experimental infection in dogs. Despite this, the natural definitive host for this cestode, as well as its genetic information, remained unknown. The objective of this study is to investigate the role of the domestic dog, the Andean fox (Lycalopex culpaeus), and other species of rodents in the life cycle of T. talicei. Molecular analysis of the mitochondrial genes of cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) was also carried out in the cestodes. For this, 13 adult cestodes and five metacestodes were collected from a domestic dog (n = 6), an Andean fox (n = 7), a northern viscacha (Lagidium peruanum) (n = 1), a yellow-rumped leaf-eared mouse (Phyllotis xanthopygus) (n = 3), and a robust tuco-tuco (Ctenomys tuconax) (n = 1). Various features of the scolex and rostellar hooks were analyzed using morphological methods. The molecular characterization of cox1 and nad1 was analyzed by standard PCR protocols. All parasites were identified as T. talicei by looking at their diagnostic features, e.g., size of their rostellar hooks, distribution of testes, and the shape of their metacestodes (fimbriocercus and polycephalic metacestodes). The analysis of the cox1 and nad1 mitochondrial genes showed 99 % and 100 % identity between them, respectively. The phylogenetic analysis indicated that T. talicei is closely related to Taenia polyacantha. Our findings confirm the domestic dog and the Andean fox as the definitive hosts and indicate that T. talicei has both a domestic and wild life cycle, as well as the participation of new species of rodents in their life cycle.