CONICET | Buscador de Institutos y Recursos Humanos

Dyoctophyma renale, the giant kidney worm, is probably the largest parasitic nematode by mass of land animals described so far and is distributed worldwide. These parasites locate in the kidney of their definitive hosts (carnivores, mainly piscivores) and have an indirect life cycle with an annelid as the main intermediate host. Humans are rarely affected, but in those that are, one or both kidneys are destroyed. In Argentina, D. renale is found mostly in dogs that live close to rivers and the infection is diagnosed by urine analysis, ultrasonography, surgery, or at necropsy. Changing climatic conditions, environmental degradation, and compromised sanitation are increasing the risk to humans. Having incomplete lipid metabolisms, helminth parasites rely on their hosts for fatty acids, cholesterol and complex lipids. The acquisition and transport of these hydrophobic molecules is crucial to these organisms, and the proteins and receptors involved in lipid transport and exchange provide potential targets for chemo- and immunotherapy. Nematodes in particular produce and secrete a wide range of novel lipid binding proteins (LBPs), many of which are structurally distinct from those of their hosts. These proteins bind several lipid classes such as fatty acids, retinoids, eicosanoids, triglycerides, phospholipids and cholesterol. The main objective of this work is to identify and characterize novel LBPs from D. renale using biophysical techniques, and to explore their value as diagnostic markers. Using the fluorescent probe DAUDA, we have detected an abundant LBP in the pseudocoelomic fluid from these organisms and we are working on its characterization. The results obtained from this work should shed light on the lipid metabolism of this unusually large nematode parasite of mammals and begin to understand its particular survival mechanisms.