Journal article
Parasitemia in an immunocompetent horse experimentally challenged with Sarcocystis neurona sporocysts
Veterinary parasitology, Vol.127(1), pp.3-8
2005
Handle:
https://hdl.handle.net/2376/107577
PMID: 15619368
Abstract
Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in Americans. Most cases are attributed to infection of the central nervous system with
Sarcocystis neurona. Parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. The objective of this study was to isolate viable
S. neurona from the blood of immunocompetent horses.
Horses used in this study received orally administered
S. neurona sporocysts (strain SN 37-R) daily for 112 days at the following doses: 100/day for 28 days, followed by 500/day for 28 days, followed by 1000/day for 56 days. On day 98 of the study, six yearling colts were selected for attempted culture of
S. neurona from blood, two testing positive, two testing suspect and two testing negative for antibodies against
S. neurona on day 84 of the study. Two 10
ml tubes with EDTA were filled from each horse by jugular venipuncture and the plasma fraction rich in mononuclear cells was pipetted onto confluent equine dermal cell cultures. The cultures were monitored weekly for parasite growth for 12 weeks. Merozoites grown from cultures were harvested and tested using
S. neurona-specific PCR with RFLP to confirm species identity. PCR products were sequenced and compared to known strains of
S. neurona.
After 38 days of in vitro incubation, one cell culture from a horse testing positive for antibodies against
S. neurona was positive for parasite growth while the five remaining cultures remained negative for parasite growth for all 12 weeks. The
Sarcocystis isolate recovered from cell culture was confirmed to be
S. neurona by PCR with RFLP. Gene sequence analysis revealed that the isolate was identical to the challenge strain SN-37R and differed from two known strains UCD1 and MIH1. To our knowledge this is the first report of parasitemia with
S. neurona in an immunocompetent horse.
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Details
- Title
- Parasitemia in an immunocompetent horse experimentally challenged with Sarcocystis neurona sporocysts
- Creators
- M.G Rossano - The Population Medicine Center, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USAH.C Schott - Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USAA.J Murphy - Diagnostic Center for Population and Animal Health, Michigan State University, East Lansing, MI 48824, USAJ.B Kaneene - The Population Medicine Center, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USAD.C Sellon - Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164, USAM.T Hines - Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164, USAT Hochstatter - Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164, USAJ.A Bell - Department of Microbiology and Molecular Genetics, B43 Food Safety and Toxicology Building, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USAL.S Mansfield - Department of Microbiology and Molecular Genetics, B43 Food Safety and Toxicology Building, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
- Publication Details
- Veterinary parasitology, Vol.127(1), pp.3-8
- Academic Unit
- Veterinary Clinical Sciences, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900546896301842
- Language
- English
- Resource Type
- Journal article