DAO 80:199-209 (2008)  -  DOI: https://doi.org/10.3354/dao01912

Myxidium scripta n. sp. identified in urinary and biliary tract of Louisiana-farmed red-eared slider turtles Trachemys scripta elegans

John F. Roberts1,5,*, Christopher M. Whipps4,6, Jerri L. Bartholomew4, Lynda Schneider2, Elliott R. Jacobson3

1Department of Infectious Disease and Pathology, College of Veterinary Medicine; 2The Electron Microscopy Core Laboratory, Biotechnology Program; 3Department of Small Animal Clinical Sciences, College of Veterinary Medicine; University of Florida, Gainesville, Florida 32610, USA
4Center for Fish Disease Research, Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA
5Present address: Thompson-Bishop-Sparks State Diagnostic Laboratory, PO Box 2209, Auburn, Alabama 36831, USA
6Present address: Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York 13210, USA

ABSTRACT: 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 × 5.1 µm and a mean polar capsule dimension of 6.6 × 3.5 µm. 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.


KEY WORDS: Myxidium · Trachemys scripta elegans · Red-eared slider turtle · Myxozoa · Kidney · Nephritis · Ultrastructure · rDNA sequence


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Cite this article as: Roberts JF, Whipps CM, Bartholomew JL, Schneider L, Jacobson ER (2008) Myxidium scripta n. sp. identified in urinary and biliary tract of Louisiana-farmed red-eared slider turtles Trachemys scripta elegans. Dis Aquat Org 80:199-209. https://doi.org/10.3354/dao01912

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