Z-007. Discovery and Prevalence of a Novel Sea Turtle Circovirus Using Metagenomic Sequencing

F. Ng1, C. Manire2, M. Breitbart1;
1Univ. of South Florida, Saint Petersburg, FL, 2Mote Marine Lab., Sarasota, FL.

Fibropapillomatosis is a debilitating proliferative disease of epizootic proportions that has severely affected sea turtle populations worldwide. Current evidence suggests that fibropapillomatosis is caused by an alpha-herpesvirus. However, since this herpesvirus has not been obtained in pure culture and shown to cause fibropapillomatosis, it is possible that there are other undescribed, co-existing viruses involved in this disease. To examine the etiology of fibropapillomatosis, viral metagenomics was used to describe the viral community found in the fibropapilloma of a Florida green sea turtle (Chelonia mydas). The fibropapilloma was homogenized and viral particles were purified based on size, density, and nuclease resistance. Shotgun sequencing of purified viral particles resulted in the discovery of a novel circovirus with 30% amino acid similarity to chicken anemia virus. The 2.1 kilobase genome of the sea turtle circovirus was completely sequenced, and PCR assays were used to determine its prevalence amongst Florida green turtles. The circovirus was detected in approximately 42% of green turtles with fibropapillomatosis (n=14) and 19% of healthy green turtles (n=27). This is the first description of a circovirus in marine animals, and it is important to understand the effects of this novel circovirus on endangered sea turtle populations. Future studies will examine the geographic distribution of this virus in sea turtles throughout the world, and determine if the circovirus plays a role in fibropapillomatosis.