Molecular identification of Sarcocystis aucheniae as the macrocyst-forming parasite of llamas

CARLETTI, T.; MARTIN, M; ROMERO, S.; MORRISON, D.A.; MARCOPPIDO, G.; JACOBSEN FLORIN-CHRISTENSEN, M.; SCHNITTGER, L.

VETERINARY PARASITOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 198 p. 396 - 400

0304-4017

The domestic South American camelids (SACs), llama (Lama glama) and alpaca (Lama paco), are frequently found to be infected with Sarcocystis parasites. Infections give rise in skeletalmuscle to macroscopic cysts (1?5 mm long) that resemble rice seeds, each containing several million living bradyzoites. The finding of cysts prevents commercialization of SAC meat,an important source of income for rural families in the Andean flatlands. Thus, development of diagnostic methods to facilitate the control of these infections is highly desirable, andthe first step to this end is the unequivocal species identification of the causative agent. Based on the cyst form and size, the infecting parasite has been described as Sarcocystisaucheniae; however, this traditional approach is not reliable as similar cysts may contain different species. To date, molecular identification has been done for a single isolate of S.aucheniae from an alpaca in Australia. In order to verify the identity of the species present in SACs of South America, the complete 18S rRNA gene was PCR-amplified and sequencedfrom macrocyst DNA obtained from three llamas of the Andean flatlands. A phylogenetic Bayesian analysis was carried out using the analyzed and available 18S rRNA sequences ofSarcocystis spp. In the constructed tree, all of the new 18S rRNA gene sequences segregated in a single clade together with the 18S rRNA gene sequence reported from an alpaca inAustralia, demonstrating that the isolated parasite is S. aucheniae, and that this parasite indiscriminately infects both domestic SACs. This work represents the first molecular identificationof the causative agent of SAC sarcocystiosis in South America, and can contribute to the development of control methods for this neglected parasitosis.