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Hammondia sp. oocysts shed by a Brazilian fox (Lycalopex vetulus) differ from Hammondia heydorni and Hammondia triffittae

Gondim, LuísF. P., Soares, RodrigoM., Osaki, SilviaC., Snak, Alessandra, Grillo, LauraR., Fernandes, NelsonL. M., de Carvalho, AndersonL.
Parasitology research 2018 v.117 no.7 pp. 2299-2304
Hammondia heydorni, Lycalopex, Neospora caninum, captive animals, definitive hosts, genetic markers, genetic variation, heat-shock protein 70, internal transcribed spacers, introns, multilocus sequence typing, oocysts, parasites, polymerase chain reaction, ribosomal DNA, ribosomal RNA, tubulin
A Brazilian fox (Lycalopex vetulus) was rescued from a highway, and 16 days after maintained in captivity, the fox shed oocysts with sizes compatible with Hammondia sp. and Neospora caninum. DNA extracted from oocysts were initially tested in two PCRs targeting the internal transcribed spacer 1 (ITS-1) of the rDNA of Hammondia heydorni and the Nc-5 gene of N. caninum. A 270-bp product was visualized in the PCR for H. heydorni. No amplification was observed for N. caninum PCR. Since ITS-1-based PCR is not sufficient to differentiate Hammondia species derived from canids, oocyst DNA was examined using multilocus sequence analysis of five genetic fragments [intron 1 of the alpha tubulin gene (intron 1), internal transcribed spaces 1 and 2 (ITS-1 and ITS-2) of the rDNA, 28S rRNA gene (D2/D3 domain), and heat shock protein 70 (Hsp70)]. The Hammondia sp. oocyst from the Brazilian fox, referred here as H-FOXBR isolate, is closely related to H. heydorni and Hammondia triffittae, but differs from these parasites in three genetic markers (alpha tubulin gene, ITS-2, and 28S rRNA). As reported by other research groups, Hammondia spp. excreted by canids are genetically diverse and may encompass additional species besides H. heydorni and H. triffittae. In this study, we confirmed that H-FOXBR has significant genetic differences in comparison to H. heydorni and H. triffittae and may represent a separate species. Further studies are needed to identify the life cycle of this parasite and to characterize the parasite stages in the intermediate and definitive hosts.