Johnson April J, Pessier Allan P, Wellehan James F X, Childress April, Norton Terry M, Stedman Nancy L, Bloom David C, Belzer William, Titus Valorie R, Wagner Robert, Brooks Jason W, Spratt Jeffrey, Jacobson Elliott R
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA.
J Wildl Dis. 2008 Oct;44(4):851-63. doi: 10.7589/0090-3558-44.4.851.
Iridoviruses of the genus Ranavirus are well known for causing mass mortality events of fish and amphibians with sporadic reports of infection in reptiles. This article describes five instances of Ranavirus infection in chelonians between 2003 and 2005 in Georgia, Florida, New York, and Pennsylvania, USA. Affected species included captive Burmese star tortoises (Geochelone platynota), a free-ranging gopher tortoise (Gopherus polyphemus), free-ranging eastern box turtles (Terrapene carolina carolina), and a Florida box turtle (Terrepene carolina bauri). Evidence for Ranavirus infection was also found in archived material from previously unexplained mass mortality events of eastern box turtles from Georgia in 1991 and from Texas in 1998. Consistent lesions in affected animals included necrotizing stomatitis and/or esophagitis, fibrinous and necrotizing splenitis, and multicentric fibrinoid vasculitis. Intracytoplasmic inclusion bodies were rarely observed in affected tissues. A portion of the major capsid protein (MCP) gene was sequenced from each case in 2003-2005 and found to be identical to each other and to Frog virus 3 (FV3) across 420 base pairs. Ranavirus infections were also documented in sympatric species of amphibians at two locations with infected chelonians. The fragment profiles of HindIII-digested whole genomic DNA of Ranavirus, isolated from a dead Burmese star tortoise and a southern leopard frog (Rana utricularia) found nearby, were similar. The box turtle isolate had a low molecular weight fragment that was not seen in the digestion profiles for the other isolates. These results suggest that certain amphibians and chelonians are infected with a similar virus and that different viruses exist among different chelonians. Amphibians may serve as a reservoir host for susceptible chelonians. This report also demonstrated that significant disease associated with Ranavirus infections are likely more widespread in chelonians than previously suspected.
蛙病毒属的虹彩病毒因可导致鱼类和两栖动物大量死亡事件而闻名，偶有其感染爬行动物的报道。本文描述了2003年至2005年间在美国佐治亚州、佛罗里达州、纽约州和宾夕法尼亚州发生的5起龟类感染蛙病毒的病例。受影响的物种包括圈养的缅甸星龟（扁东方龟）、一只自由放养的沙龟（穴小龟）、自由放养的东部箱龟（卡罗莱纳箱龟指名亚种）和一只佛罗里达箱龟（卡罗莱纳箱龟鲍里亚种）。在1991年佐治亚州和1998年得克萨斯州东部箱龟此前原因不明的大量死亡事件的存档材料中也发现了蛙病毒感染的证据。受影响动物的一致病变包括坏死性口炎和/或食管炎、纤维蛋白性和坏死性脾炎以及多中心纤维蛋白样血管炎。在受影响的组织中很少观察到胞质内包涵体。对2003 - 2005年每个病例的主要衣壳蛋白（MCP）基因的一部分进行了测序，发现它们在420个碱基对中彼此相同，且与蛙病毒3（FV3）相同。在两个有感染龟类的地点，同域分布的两栖动物物种中也记录到了蛙病毒感染。从一只死亡的缅甸星龟和附近发现的一只南方豹蛙（猪蛙）中分离出的蛙病毒，经HindIII消化的全基因组DNA片段图谱相似。箱龟分离株有一个低分子量片段，在其他分离株的消化图谱中未见到。这些结果表明，某些两栖动物和龟类感染了相似的病毒，且不同龟类中存在不同的病毒。两栖动物可能是易感龟类的储存宿主。本报告还表明，与蛙病毒感染相关的重大疾病在龟类中的分布可能比以前怀疑的更广泛。
