title: Characterization of the Oregon isolate of Neospora hughesi from a horse.
abstract: Neospora hughesi was isolated in cell cultures inoculated with homogenate of spinal cord from a horse in Oregon. Tachyzoites of this Oregon isolate of N. hughesi were maintained continuously by cell culture passage and tachyzoites were infective to immunosuppressed mice. Gamma interferon gene knockout (KO) mice injected with tachyzoites developed fatal myocarditis and numerous tachyzoites were seen in lesions. Gerbils (Meriones unguiculatus) inoculated with tachyzoites developed antibodies (> or = 1:500) as indicated by the Neospora caninum agglutination test but did not develop clinical signs, and Neospora organisms were not demonstrable in their tissues. Tissue cysts were not found in gerbils, nude mice, KO mice, immunosuppressed outbred Swiss Webster mice, or BALB/c mice injected with the Oregon isolate of N. hughesi. Ultrastructurally, tachyzoites of the Oregon isolate from the myocardium of infected KO mice and from cell culture were similar to N. caninum tachyzoites. Western blot analysis using NcSAG1 and NcSRS2 polyclonal and monoclonal antibodies and characterization of the internal transcribed spacer 1 sequences from the equine isolates and different isolates of N. caninum from dogs and cattle indicated that the Oregon isolate of N. hughesi is distinct from N. caninum isolates from cattle and dogs.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Livestock and Poultry Sciences Institute, Beltsville Agricultural Research Center, Maryland 20705-2350, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Dubey
authors.forename: S
authors.initials: S
authors.lastname: Liddell
authors.forename: D
authors.initials: D
authors.lastname: Mattson
authors.forename: C A
authors.initials: CA
authors.lastname: Speert
authors.forename: D K
authors.initials: DK
authors.lastname: Howe
authors.forename: M C
authors.initials: MC
authors.lastname: Jenkins
mesh_terms: D000818:Animals; D001483:Base Sequence; D003048:Coccidiosis / Q000469:parasitology / Q000662:veterinary*; D004275:DNA, Ribosomal / Q000737:chemistry; D005065:Euthanasia; D005849:Gerbillinae; D006734:Horse Diseases / Q000469:parasitology*; D006736:Horses; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D008819:Mice, Nude; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D018688:Neospora / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D009922:Oregon; D012376:Rodent Diseases / Q000469:parasitology*; D013116:Spinal Cord / Q000469:parasitology
chemical_list: D004275:DNA, Ribosomal