title: Immunohistochemical and ultrastructural evidence for Neospora caninum tissue cysts in skeletal muscles of naturally infected dogs and cattle.
abstract: Protozoan stages were detected in the skeletal muscles of four dogs suffering from neosporosis and two neonatal calves with confirmed Neospora caninum- infection which could be immunohistochemically labelled by an antiserum against the bradyzoite-specific antigen BAG-5. In one calf, a tissue cyst was labelled by an antiserum against the N. caninum isolate NC-1. Ultrastructurally, a 0.3-1 microm-thick cyst wall surrounded the labelled parasites. The cysts were located within myofibres and contained varying numbers of bradyzoites each measuring 5.2(+/-0.6) x 1.6(+/-0.3) microm. The encysted stages showed typical ultrastructural features of N. caninum bradyzoites with subterminal nuclei, electron-dense rhoptries, and micronemes that were orientated perpendicular to the zoite pellicle. Immunohistochemistry and serology did not reveal any evidence for co-infection with Toxoplasma gondii. The detection of tissue cysts in skeletal muscle of N. caninum-infected intermediate hosts is of major epidemiological importance for the understanding of how definitive or intermediate carnivorous hosts become infected with N. caninum.
authors: Institute of Pathology, School of Veterinary Medicine, Bünteweg 17, D-30559, Hannover, Germany. martin.peters@tiho-hannover.de
authors: M
authors: M
authors: Peters
authors: E
authors: E
authors: Lütkefels
authors: A R
authors: AR
authors: Heckeroth
authors: G
authors: G
authors: Schares
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology* / Q000473:pathology; D003048:Coccidiosis / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000469:parasitology* / Q000473:pathology; D004285:Dogs; D007150:Immunohistochemistry / Q000662:veterinary; D008854:Microscopy, Electron / Q000662:veterinary; D018482:Muscle, Skeletal / Q000469:parasitology* / Q000473:pathology / Q000648:ultrastructure; D018688:Neospora / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D000953:Antigens, Protozoan