Characterization of the major pseudocoelomic proteins of the giant kidney worm, Dioctophyme renale

A. NAHILI GIORELLO; DANIELA PEDRASSANI; MARCO ANDRE; ROSANGELA ZACARIAS MACHADO; MARCOS J. BUTTI; NILDA E. RADMAN; MALCOLM W. KENNEDY; BETINA CÓRSICO; GISELA R. FRANCHINI

Congreso; Molecular and Cellular Biology of Helminths IX; 2018

Dioctophyma renale, commonly known as the giant kidney worm develops in, and completely destroys mammalian kidneys, and is thereby a debilitating and potentially lethal parasite of humans, domestic animals and endangered wildlife. Despite the importance and threat for humans of this parasitic disease there is little information about the molecular bases of this organism (e.g. genome and proteome). Among domestic animals it is particularly pathogenic and common in dogs that live close to rivers and the infection is diagnosed only by urine analysis, ultrasonography, surgery, or at necropsy. Moreover, although the parasite is usually located in one of the kidneys, worms may also develop to adulthood in sites other than these organs, such as the abdominal cavity, subcutaneous tissues, etc. Given this, current diagnostic methods are of poor sensitivity, frequently giving false negative results. In this regard, recently published data show the existence of soluble antigens from the esophagus of D. renale may help to determine infections in dogs. Our work is aimed at discovering specific proteins from D. renale that might be useful as new diagnostic markers for their use in dogs and potentially in humans. So far, we characterised the soluble proteins of pseudocelomic fluid (PCF) of adult parasites. Two proteins, P17 and P44, dominate the PCF of both male and females. P17 is of 16,622 Da by mass spectrometry, and accounts for the intense red colour of the adult parasites. It may function to carry or scavenge oxygen and be related to the ?nemoglobins? found in other nematode clades. P44 is of 44,460 Da and was found to associate with fatty acids. Both proteins were studied by immunoassays in comparison with esophagus proteins to test their potential as diagnostic markers. Interestingly, while P44 was found to be immunogenic in the dog sampled, P17 was not.