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The Journal of parasitology1991; 77(2); 212-218;

Sarcocystis neurona n. sp. (Protozoa: Apicomplexa), the etiologic agent of equine protozoal myeloencephalitis.

Abstract: Sarcocystis neuronan n. sp. is proposed for the apicomplexan taxon associated with myeloencephalitis in horses. Only asexual stages of this parasite presently are known, and they are found within neuronal cells and leukocytes of the brain and spinal cord. The parasite is located in the host cell cytoplasm, does not have a parasitophorous vacuole, and divides by endopolygeny. Schizonts are 5-35 microns x 5-20 microns and contain 4-40 merozoites arranged in a rosette around a prominent residual body. Merozoites are approximately 4 x 1 micron, have a central nucleus, and lack rhoptries. Schizonts and merozoites react with Sarcocystis cruzi antiserum but not with Caryospora bigenetica. Toxoplasma gondii, Hammondia hammondi, or Neospora caninum antisera in an immunohistochemical test.
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Publication Date: 1991-04-01 PubMed ID: 1901359
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  • Comparative Study
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article is about a new species of parasite named Sarcocystis neurona that causes myeloencephalitis, a brain and spinal cord disease, in horses. The study also describes the characteristics of this parasite and its asexual reproduction stages.

About Sarcocystis neurona

The research paper introduces a new species of Apicomplexa taxon, named Sarcocystis neurona. This parasite is associated with a disease called myeloencephalitis, which affects the brain and spinal cord in horses. At present, only the asexual stages of this parasite are known.

  • The parasite resides within the neurons and leukocytes of the brain and spinal cord of the horse.
  • The location of the parasite is within the host cell cytoplasm; it does not possess a parasitophorous vacuole and reproduces by endopolygeny, a form of asexual reproduction.

The Features of Sarcocystis neurona

The paper then delves into the physical attributes of the parasite:

  • Schizonts, the asexual reproduction stage of the parasite, measured in this study are found to be between 5-35 microns x 5-20 microns in size and contain 4-40 merozoites, which are arranged in a rosette around a prominent residual body.
  • Merozoites, the proliferating form of the parasite, are seen to be approximately 4 x 1 micron in size, possess a central nucleus, and lack rhoptries, specialized secretory organelles found in apicomplexan parasites.

Inbuilt Defense Mechanism

The paper also found that these schizonts and merozoites react, or bind, to antibodies derived from another species known as Sarcocystis cruzi:

  • This suggests that the Sarcocystis neurona parasites carry antigens (proteins that can elicit an immune response) that can bind to Sarcocystis cruzi antibodies, hence potentially indicating a mechanism of immune evasion or defense.
  • In contrast, the parasites do not react to antibodies from Caryospora bigenetica, Toxoplasma gondii, Hammondia hammondi, or Neospora caninum, indicating potential differences in their antigenic profiles.

Cite This Article

APA
Dubey JP, Davis SW, Speer CA, Bowman DD, de Lahunta A, Granstrom DE, Topper MJ, Hamir AN, Cummings JF, Suter MM. (1991). Sarcocystis neurona n. sp. (Protozoa: Apicomplexa), the etiologic agent of equine protozoal myeloencephalitis. J Parasitol, 77(2), 212-218.

Publication

The Journal of parasitology
ISSN: 0022-3395
NlmUniqueID: 7803124
Country: United States
Language: English
Volume: 77
Issue: 2
Pages: 212-218

Researcher Affiliations

Dubey, J P
  • Livestock and Poultry Sciences Institute, U.S. Department of Agriculture, Beltsville, Maryland 20705.
Davis, S W
    Speer, C A
      Bowman, D D
        de Lahunta, A
          Granstrom, D E
            Topper, M J
              Hamir, A N
                Cummings, J F
                  Suter, M M

                    MeSH Terms

                    • Animals
                    • Encephalomyelitis / parasitology
                    • Encephalomyelitis / veterinary
                    • Horse Diseases / parasitology
                    • Horses
                    • Microscopy, Electron
                    • Sarcocystis / anatomy & histology
                    • Sarcocystis / classification
                    • Sarcocystis / ultrastructure
                    • Sarcocystosis / parasitology
                    • Sarcocystosis / veterinary

                    Citations

                    This article has been cited 22 times.
                    1. O'Byrne AM, Lambourn DM, Rejmanek D, Haman K, O'Byrne M, VanWormer E, Shapiro K. Sarcocystis neurona Transmission from Opossums to Marine Mammals in the Pacific Northwest. Ecohealth 2021 Mar;18(1):84-94.
                      doi: 10.1007/s10393-021-01536-wpubmed: 34213686google scholar: lookup
                    2. Ma CL, Ye YL, Wen T, Huang ZM, Pan J, Hu JJ, Tao JP, Song JL. Prevalence and morphological and molecular characteristics of Sarcocystis bertrami in horses in China. Parasite 2020;27:1.
                      doi: 10.1051/parasite/2019078pubmed: 31908266google scholar: lookup
                    3. Bowden GD, Land KM, O'Connor RM, Fritz HM. High-throughput screen of drug repurposing library identifies inhibitors of Sarcocystis neurona growth. Int J Parasitol Drugs Drug Resist 2018 Apr;8(1):137-144.
                      doi: 10.1016/j.ijpddr.2018.02.002pubmed: 29547840google scholar: lookup
                    4. Reed SM, Furr M, Howe DK, Johnson AL, MacKay RJ, Morrow JK, Pusterla N, Witonsky S. Equine Protozoal Myeloencephalitis: An Updated Consensus Statement with a Focus on Parasite Biology, Diagnosis, Treatment, and Prevention. J Vet Intern Med 2016 Mar-Apr;30(2):491-502.
                      doi: 10.1111/jvim.13834pubmed: 26857902google scholar: lookup
                    5. Barbosa L, Johnson CK, Lambourn DM, Gibson AK, Haman KH, Huggins JL, Sweeny AR, Sundar N, Raverty SA, Grigg ME. A novel Sarcocystis neurona genotype XIII is associated with severe encephalitis in an unexpectedly broad range of marine mammals from the northeastern Pacific Ocean. Int J Parasitol 2015 Aug;45(9-10):595-603.
                      doi: 10.1016/j.ijpara.2015.02.013pubmed: 25997588google scholar: lookup
                    6. Dubey JP, Howe DK, Furr M, Saville WJ, Marsh AE, Reed SM, Grigg ME. An update on Sarcocystis neurona infections in animals and equine protozoal myeloencephalitis (EPM). Vet Parasitol 2015 Apr 15;209(1-2):1-42.
                      doi: 10.1016/j.vetpar.2015.01.026pubmed: 25737052google scholar: lookup
                    7. Awinda PO, Mealey RH, Williams LB, Conrad PA, Packham AE, Reif KE, Grause JF, Pelzel-McCluskey AM, Chung C, Bastos RG, Kappmeyer LS, Howe DK, Ness SL, Knowles DP, Ueti MW. Serum antibodies from a subset of horses positive for Babesia caballi by competitive enzyme-linked immunosorbent assay demonstrate a protein recognition pattern that is not consistent with infection. Clin Vaccine Immunol 2013 Nov;20(11):1752-7.
                      doi: 10.1128/CVI.00479-13pubmed: 24049108google scholar: lookup
                    8. Olias P, Meyer A, Klopfleisch R, Lierz M, Kaspers B, Gruber AD. Modulation of the host Th1 immune response in pigeon protozoal encephalitis caused by Sarcocystis calchasi. Vet Res 2013 Feb 11;44(1):10.
                      doi: 10.1186/1297-9716-44-10pubmed: 23398807google scholar: lookup
                    9. Varaschin MS, Hirsch C, Wouters F, Nakagaki KY, Guimarães AM, Santos DS, Bezerra PS Jr, Costa RC, Peconick AP, Langohr IM. Congenital neosporosis in goats from the State of Minas Gerais, Brazil. Korean J Parasitol 2012 Mar;50(1):63-7.
                      doi: 10.3347/kjp.2012.50.1.63pubmed: 22451736google scholar: lookup
                    10. Prakas P, Kutkienė L, Sruoga A, Butkauskas D. Sarcocystis sp. from the herring gull (Larus argentatus) identity to Sarcocystis wobeseri based on cyst morphology and DNA results. Parasitol Res 2011 Dec;109(6):1603-8.
                      doi: 10.1007/s00436-011-2421-5pubmed: 21597959google scholar: lookup
                    11. Rejmanek D, Miller MA, Grigg ME, Crosbie PR, Conrad PA. Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California. Vet Parasitol 2010 May 28;170(1-2):20-9.
                      doi: 10.1016/j.vetpar.2009.12.045pubmed: 20226596google scholar: lookup
                    12. Ellison S, Witonsky S. Evidence that antibodies against recombinant SnSAG1 of Sarcocystis neurona merozoites are involved in infection and immunity in equine protozoal myeloencephalitis. Can J Vet Res 2009 Jul;73(3):176-83.
                      pubmed: 19794889
                    13. Miller MA, Barr BC, Nordhausen R, James ER, Magargal SL, Murray M, Conrad PA, Toy-Choutka S, Jessup DA, Grigg ME. Ultrastructural and molecular confirmation of the development of Sarcocystis neurona tissue cysts in the central nervous system of southern sea otters (Enhydra lutris nereis). Int J Parasitol 2009 Oct;39(12):1363-72.
                      doi: 10.1016/j.ijpara.2009.04.014pubmed: 19527725google scholar: lookup
                    14. Hoane JS, Morrow JK, Saville WJ, Dubey JP, Granstrom DE, Howe DK. Enzyme-linked immunosorbent assays for detection of equine antibodies specific to Sarcocystis neurona surface antigens. Clin Diagn Lab Immunol 2005 Sep;12(9):1050-6.
                      doi: 10.1128/CDLI.12.9.1050-1056.2005pubmed: 16148170google scholar: lookup
                    15. Elsheikha HM, Murphy AJ, Mansfield LS. Phylogenetic congruence of Sarcocystis neurona Dubey et al., 1991 (Apicomplexa: Sarcocystidae) in the United States based on sequence analysis and restriction fragment length polymorphism (RFLP). Syst Parasitol 2005 Jul;61(3):191-202.
                      doi: 10.1007/s11230-005-3163-5pubmed: 16025209google scholar: lookup
                    16. Spencer JA, Deinnocentes P, Moyana EM, Guarino AJ, Ellison SE, Bird RC, Blagburn BL. Cytokine gene expression in response to SnSAG1 in horses with equine protozoal myeloencephalitis. Clin Diagn Lab Immunol 2005 May;12(5):644-6.
                      doi: 10.1128/CDLI.12.5.644-646.2005pubmed: 15879026google scholar: lookup
                    17. Elsheikha HM, Murphy AJ, Mansfield LS. Prevalence of Sarcocystis species sporocysts in Northern Virginia opossums (Didelphis virginiana). Parasitol Res 2004 Aug;93(5):427-31.
                      doi: 10.1007/s00436-004-1150-4pubmed: 15205944google scholar: lookup
                    18. Elsheikha HM, Mansfield LS. Determination of the activity of sulfadiazine against Besnoitia darlingi tachyzoites in cultured cells. Parasitol Res 2004 Aug;93(5):423-6.
                      doi: 10.1007/s00436-004-1133-5pubmed: 15205942google scholar: lookup
                    19. Elsheikha HM, Saeed MA, Fitzgerald SD, Murphy AJ, Mansfield LS. Effects of temperature and host cell type on the in vitro growth and development of Sarcocystis falcatula. Parasitol Res 2003 Sep;91(1):22-6.
                      doi: 10.1007/s00436-003-0902-xpubmed: 12851811google scholar: lookup
                    20. Njoku CJ, Saville WJ, Reed SM, Oglesbee MJ, Rajala-Schultz PJ, Stich RW. Reduced levels of nitric oxide metabolites in cerebrospinal fluid are associated with equine protozoal myeloencephalitis. Clin Diagn Lab Immunol 2002 May;9(3):605-10.
                      doi: 10.1128/cdli.9.3.605-610.2002pubmed: 11986267google scholar: lookup
                    21. Liang FT, Granstrom DE, Zhao XM, Timoney JF. Evidence that surface proteins Sn14 and Sn16 of Sarcocystis neurona merozoites are involved in infection and immunity. Infect Immun 1998 May;66(5):1834-8.
                      doi: 10.1128/IAI.66.5.1834-1838.1998pubmed: 9573058google scholar: lookup
                    22. Silva TMVD, De Santi M, Gonçalves LR, Merino MMJ, André MR, Machado RZ. Reactivity against Sarcocystis neurona and Sarcocystis falcatula-like in horses from Southeastern and Midwestern Brazil. Rev Bras Parasitol Vet 2023;32(3):e007623.
                      doi: 10.1590/S1984-29612023031pubmed: 37283358google scholar: lookup
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