Genetic Diversity of Dioctophyma renale in Northeast Argentina and Southern Brazil

LUCAS FEDERICO ARCE; FLORENCIA FACELLI FERNÁNDEZ; NAHILI GIORELLO; MARCOS BUTTI; LUCAS MALDONADO; JUAN PABLO ARRABAL; MARÍA BELÉN NATALINI; MARTÍN KOWALESWKI; DANIELA PEDRASSANI; FLORENCIA ZILI; GISELA RAQUEL FRANCHINI; PABLO MARÍN BELDOMENICO; LAURA KAMENETZKY

Encuentro; Molecular Parasitology Meeting XXXI; 2020

Genetics Society of America

The Northeast of Argentina is one of the most diverse ecosystems on earth, hosting 7% of the world´s animal species. These areas suffer the anthropic impact that involves the presence of companion animals (dogs and cats) and livestock for consumption. These animals are exotic to the region and carry parasites of risk for wild animals and for man, such as the nematode Dioctophyma renale. Only a few reports provide information on the helminths that host wild carnivores in this region, and much less is known about their genomes. Due to the existing ignorance and the risk that it may imply for conservation, we believe it is essential to carry out genomic studies of parasites present in wild carnivores in northeastern Argentina. The comparative analysis of their genomes will allow the design of new molecular tools for the sensitive detection of helminths that cause risk diseases from domestic to wild carnivores and to determine the parasitic species that affect them. Dioctophyma renale is a parasitic nematode that infects the kidney of mammals (mainly Order Carnivora). It can grow and exceed the meter, destroying the kidney. Therefore, its infection is strongly debilitating and even fatal. Numerous cases in veterinary clinics were observed on the Argentine coast. A prevalence in domestic dogs of 36.3% was determined on the coasts of Río de la Plata. In addition, there are reports of infections by this same parasite in wild carnivores including maned wolf (Crysocyon brachyurus); making this parasite a possible threat to the conservation of some endangered species.From genome Project (developed by our laboratory), a mitochondrial genome of D. renale was assembled and three molecular markers of different sizes from cytochrome oxidase I (COX1) gene were designed. Forty-six adults of Dioctophyma renale were collected from interventions in veterinary clinics and from necropsies of wild fauna in different locations in northeastern Argentina and southern Brazil. DNA was extracted from each sample and those markers were amplified by PCR. The amplified products were typed by SNPs analysis and phylogenetically analyzed with sequences available in the GenBank, witch came from Japan, Peru, Canada and Iran. Local genetic variants of South America were observed, without geographic differentiation between the localities of Brazil and Argentina, but a great separation with respect to the sequences of other regions of the world. Nor was any structuring by host species observed. The phylogenies constructed with the different markers are consistent with each other. Although the largest markers showed more diversity, in all cases clustering was consistent with the observed in the smallest marker. Molecular evidence suggests that Dioctophyma renale populations were in South America long enough to develop local genetic variants. They could have come from the north of the continent and dispersed between Brazil and Argentina on more than one occasion. Finally, the same variants can infect and be transmitted between domestic and wild mammals in the studied region. New markers based on the nuclear genome are being designed to complement the analyzes carried out. In addition, samples of possible paratenic hosts and intermediates are being collected in order to obtain genetic information on the complete life cycle of D. renale.