Roberts John F, Whipps Christopher M, Bartholomew Jerri L, Schneider Lynda, Jacobson Elliott R
Department of Infectious Disease and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA.
Dis Aquat Organ. 2008 Aug 7;80(3):199-209. doi: 10.3354/dao01912.
During a necropsy investigation of a mortality event occurring at a turtle farm in Assumption Parish, Louisiana, spores of a myxozoan were identified in the renal tubules in 3 of 6, the gall bladder lumen in 2 of 6, and the bile ductule in 1 of 6 red eared slider turtles Trachemys scripta elegans. In total, myxozoa were identified in 4 of 6 turtles. In 1 turtle, renal tubules contained numerous mature spores, had epithelial hyperplasia, granulomatous transformation, compression of adjacent tubules and interstitial lymphocytic nephritis. The genus of myxozoan was Myxidium, based on spore morphology in cytological preparations, in histologic section, and by electron microscopy. In cytological preparation the spores had mean dimensions of 18.8 x 5.1 microm and a mean polar capsule dimension of 6.6 x 3.5 microm. Electron microscopy showed renal tubules contained plasmodia with disporoblasts with spores in various stages of maturation. Ultrastructure of mature spores demonstrated a capsule containing 2 asymmetrical overlapping valves and polar capsules containing a polar filament coiled 6 to 8 times and surrounded by a membrane composed of a double layer wall. The small subunit rDNA gene sequence was distinct from all other Myxidium species for which sequences are available. Additionally, this is the first Myxidium species recovered from a North American chelonian to receive genetic analysis. Although T. s. elegans is listed as a host for Myxidium chelonarum, this newly described species of Myxidium possessed larger spores with tapered ends; thus, we described it as a new species, Myxidium scripta n. sp. This report documents a clinically significant nephropathy and genetic sequence from a Myxidium parasite affecting a freshwater turtle species in North America.
在对路易斯安那州阿萨姆普申教区一家海龟养殖场发生的死亡事件进行尸检调查期间，在6只红耳龟（滑龟指名亚种）中的3只的肾小管、6只中的2只的胆囊腔以及6只中的1只的胆小管中发现了一种粘孢子虫的孢子。总共在6只海龟中的4只身上发现了粘孢子虫。在1只海龟中，肾小管含有大量成熟孢子，出现上皮增生、肉芽肿性转化、相邻肾小管受压以及间质性淋巴细胞性肾炎。根据细胞学制剂、组织学切片中的孢子形态以及电子显微镜观察，确定该粘孢子虫属为粘孢虫属。在细胞学制剂中，孢子的平均尺寸为18.8×5.1微米，平均极囊尺寸为6.6×3.5微米。电子显微镜显示肾小管含有含有孢子母细胞的疟原虫，孢子处于不同成熟阶段。成熟孢子的超微结构显示有一个包含两个不对称重叠瓣膜的囊以及包含盘绕6至8次并被由双层壁组成的膜包围的极丝的极囊。小亚基rDNA基因序列与所有其他有可用序列的粘孢虫属物种不同。此外，这是从北美龟类中分离出并接受基因分析的首个粘孢虫属物种。尽管滑龟指名亚种被列为龟粘孢虫的宿主，但这种新描述的粘孢虫属物种具有末端渐细的较大孢子；因此，我们将其描述为一个新物种，即滑龟粘孢虫（Myxidium scripta n. sp.）。本报告记录了一种影响北美淡水龟类的粘孢虫寄生虫引起的具有临床意义的肾病及基因序列。
