RESUMEN
The life cycles of many parasitic nematodes include terrestrial gastropods as intermediate hosts. Over the past few decades, a number of cases of parasitism between molluscs and medically-important nematodes have been reported in Brazil, in particular, those involving the invasive giant African gastropod, Achatina fulica, and zoonoses caused by the nematodes Angiostrongylus cantonensis and Angiostrongylus costaricensis, the etiological agents of neuroangiostrongyliasis and abdominal angiostrongyliasis, respectively. In the present study, larvae found infecting A. fulica, Latipes erinaceus, and Thaumastus taunaisii, from two localities in the Brazilian state of Rio de Janeiro were characterized using light and scanning electron microscopy, and sequences of the 18S rRNA and MT-CO1 genes. Genetic markers allowed to identify the larvae collected in the present study as Cruzia tentaculata, whose adults parasitize didelphid marsupials in the Americas. These findings indicate that both native and non-native gastropods may act as intermediate hosts and represent a previously unnoticed heteroxenous life cycle of C. tentaculata.
RESUMEN
Agroforestry is an alternative kind of land use where the native vegetation is surrounded or intercalated by crops of economic interest. This system may maintain species richness by promoting the habitat heterogeneity or serving as ecological corridors. The aim of this study was to describe the gastrointestinal helminth fauna and to analyse the parasitological parameters of the helminth communities of six sigmodontine rodents in a cocoa agroforestry system in the municipality of Ilhéus, state of Bahia, Northeast Brazil. This is a novel study of helminth fauna in this kind of agroforestry. Rodents were captured in live-traps and euthanised for helminth recovery. Specimens were counted and identified to the species level whenever possible. Helminth abundance, intensity, and prevalence were calculated for each species and each host. The total abundance and prevalence of helminths were compared among localities and three attributes of the host: species, gender and age using generalised linear models. Considering all rodents, 52.14% of them were parasitised with at least one helminth species. Eight nematode species were identified and another seven morphospecies were identified to the genus level. The most abundant species were Hassalstrongylus epsilon, Stilestrongylus eta, Guerrerostrongylus zetta, and Syphacia alata. The opportunistic host species Oligoryzomys nigripes and Akodon cursor, besides the water rat Nectomys squamipes, were the most infected species for helminth parasites. Hylaeamys seuanezi was also an important host with the highest helminth species richness. This is the first report of the helminth fauna for this host. The locality most distant from the native vegetation and closest to the city had the highest helminth prevalence and mean species richness. The species richness in the helminth communities of Euryoryzomys russatus, N. squamipes and O. nigripes in these Cabruca agroforestries were within the range found in studies carried out in Atlantic Forest areas.
