DAO 89:51-61 (2010)  -  DOI: https://doi.org/10.3354/dao02180

Myxobolus neurophilus: morphologic, histopathologic and molecular characterization

Lester Khoo1,6,*, Frederick A. Rommel2,†, Stephen A. Smith3, Matt J. Griffin4, Linda M. Pote5

1University of Pennsylvania, School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA
2Pennsylvania Veterinary Laboratory, 2305 Cameron Street, Harrisburg, Pennsylvania 17110, USA
3Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Duck Pond Drive, Blacksburg, Virginia 24061, USA
4Mississippi State University, College of Veterinary Medicine, PO Box 197, Stoneville, Mississippi 38776, USA
5Mississippi State University, College of Veterinary Medicine, PO Box 6100, Mississippi State, Mississippi 39762, USA
6Present address: Mississippi State University, College of Veterinary Medicine, PO Box 197, Stoneville, Mississippi 38776, USA
*Email:
Deceased

ABSTRACT: Archived tissues from affected yellow perch Perca flavescens, as well as fresh submissions of juvenile yellow perch, walleye, fathead minnows, golden shiners and smallmouth bass cultured in the same pond or from a shared water source were examined for the presence of Myxobolus neurophilus. Archived tissues were sectioned and stained with hematoxylin and eosin or with Giemsa, revealing myxozoan spores consistent with M. neurophilus. The myxospores were found beneath the ependymal lining of the central canal of the brain or free within the stratum periventriculare, with minimal or no inflammation. Unstained and stained (Wright Giemsa or Lugol’s iodine) touch impressions of the brains from fresh submissions of all 5 fish species revealed similar myxozoan spores only in the brains of yellow perch. These were Giemsa-positive, with no iodinophilous vacuoles evident. Portions of the affected brains were fixed in neutral buffered 10% formalin and sectioned for histology. Pseudocysts containing myxospores were only evident in sections of the brains and spinal cords of yellow perch. Mild mononuclear meningoencephalitis was present when myxospores appeared outside of the pseudocysts. Brains fixed in 5% gluteraldehyde for scanning electron microscopic examination revealed pyriform myxospores with a smooth capsular surface. Sequencing and phylogenetic analysis of the 18S small subunit ribosomal DNA gene placed the organism within the family Myxobolidae, with no direct matches to sequences available via GenBank. Aquatic annelids from sediment obtained from the affected pond were negative for actinospores.


KEY WORDS: Yellow perch · Myxobolus neurophilus · Myxozoan


Full text in pdf format 
Cite this article as: Khoo L, Rommel FA, Smith SA, Griffin MJ, Pote LM (2010) Myxobolus neurophilus: morphologic, histopathologic and molecular characterization. Dis Aquat Org 89:51-61. https://doi.org/10.3354/dao02180

Export citation
Mail this link - Contents Mailing Lists - RSS
- -