DAO 37:89-97 (1999)  -  doi:10.3354/dao037089

Association of herpesvirus with fibropapillomatosis of the green turtle Chelonia mydas and the loggerhead turtle Caretta caretta in Florida

Joel K. Lackovich1, Daniel R. Brown2, Bruce L. Homer2, Richard L. Garber3, Douglas R. Mader4, Ritchie H. Moretti4, Amy D. Patterson4, Lawrence H. Herbst5, Jorge Oros6, Elliott R. Jacobson6, Sadie S. Curry7, Paul A. Klein7,*

1Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida 32610, USA
2Department of Pathobiology, University of Florida, Gainesville, Florida 32611, USA
3PathoGenesis Corporation, Seattle, Washington 98119, USA
4The Turtle Hospital, Hidden Harbor Marine Environmental Project, Marathon, Florida 33050, USA
5The Institute for Animal Studies, Albert Einstein College of Medicine, Bronx, New York 10461, USA
6Department of Small Animal Clinical Sciences, University of Florida, Gainesville, Florida 32611, USA
7Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida 32610, USA
*Addressee for correspondence. E-mail:

ABSTRACT: Sea turtle fibropapillomatosis (FP) is a disease marked by proliferation of benign but debilitating cutaneous fibropapillomas and occasional visceral fibromas. Transmission experiments have implicated a chloroform-sensitive transforming agent present in filtered cell-free tumor homogenates in the etiology of FP. In this study, consensus primer PCR methodology was used to test the association of a chelonian herpesvirus with fibropapillomatosis. Fibropapilloma and skin samples were obtained from 17 green and 2 loggerhead turtles affected with FP stranded along the Florida coastline. Ninety-three cutaneous and visceral tumors from the 19 turtles, and 33 skin samples from 16 of the turtles, were tested. All turtles affected with FP had herpesvirus associated with their tumors as detected by PCR. Ninety-six percent (89/93) of the tumors, but only 9% (3/33) of the skin samples, from affected turtles contained detectable herpesvirus. The skin samples that contained herpesvirus were all within 2 cm of a fibropapilloma. Also, 1 of 11 scar tissue samples from sites where fibropapillomas had been removed 2 to 51 wk earlier from 5 green turtles contained detectable herpesvirus. None of 18 normal skin samples from 2 green and 2 loggerhead turtles stranded without FP contained herpesvirus. The data indicated that herpesvirus was detectable only within or close to tumors. To determine if the same virus infected both turtle species, partial nucleotide sequences of the herpesvirus DNA polymerase gene were determined from 6 loggerhead and 2 green turtle samples. The sequences predicted that herpesvirus of loggerhead turtles differed from those of green turtles by only 1 of 60 amino acids in the sequence examined, indicating that a chelonian herpesvirus exhibiting minor intratypic variation was the only herpesvirus present in tumors of both green and loggerhead turtles. The FP-associated herpesvirus resisted cultivation on chelonian cell lines which support the replication of other chelonian herpesviruses. These results lead to the conclusion that a chelonian herpesvirus is regularly associated with fibropapillomatosis and is not merely an incidental finding in affected turtles.


KEY WORDS: Sea turtles · Chelonia mydas · Caretta caretta · Fibropapillomatosis · Chelonian herpesvirus


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