Fibropapillomatosis in sea turtles: could the parasites Spirorchiidae (Trematoda: Digenea) be possible vectors of Chelonid Alphaherpesvirus 5 (ChHV5)?

• Grant number: 19/11096-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2019
• End date: July 31, 2020
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Eliana Reiko Matushima
• Grantee: Daniel Yudi Miyahara Nakamura
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Fibropapillomatosis (FP) is a neoplasm globally reported in sea turtles, especially in green turtles (Chelonia mydas). Although the manifestation of tumors is multifactorial, there is an agreement that the etiological agent of FP is Chelonid alphaherpesvirus 5 (ChHV5), whose mechanical vector is still unknown. The Spirorchiidae family belongs to a group of digenetic trematodes of Platyhelminthes phylum, comprising 19 genera, of which 10 parasitize the cardiovascular system of sea turtles as their final host, being pointed as a cause of weakness and mortality of a large number of green turtles, in addition to possible vectors of ChHV5. The aim of the present study is to evaluate the possibility of Spirorchiidae being the mechanical vector of ChHV5. For this, tissue samples with and without FP, as well as adult trematodes, will be collected from C. mydas carcasses found in the region of Ubatuba. It is intended (I) to verify if carcasses with FP have a higher prevalence of parasites than carcasses without FP; (II) to correlate molecular analysis using PCR to detect, in tissue samples of C. mydas, the presence of ChHV5 even in its latent state (from the UL18, UL22, UL27, F-US3B and GTHV primers) and the presence of Spirorchiidae (from the ITS2 and 28S regions of the rDNA of the parasites); and (III) to carry out the molecular analysis using PCR to detect the presence of herpesvirus in the DNA extracted from adult individuals of Spirorchiidae, which, if confirmed, would be strong evidence of the parasites' capacity to carry viral DNA.