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Journal of clinical microbiology1992; 30(12); 3122-3126; doi: 10.1128/jcm.30.12.3122-3126.1992

Antibody to a recombinant merozoite protein epitope identifies horses infected with Babesia equi.

Abstract: Horses infected with Babesia equi were previously identified by the presence of antibodies reactive with a merozoite surface protein epitope (D. P. Knowles, Jr., L. E. Perryman, L. S. Kappmeyer, and S. G. Hennager. J. Clin. Microbiol. 29:2056-2058, 1991). The antibodies were detected in a competitive inhibition enzyme-linked immunosorbent assay (CI ELISA) by using monoclonal antibody 36/133.97, which defines a protein epitope on the merozoite surface. The gene encoding this B. equi merozoite epitope was cloned and expressed in Escherichia coli. The recombinant merozoite protein, designated equi merozoite antigen 1 (EMA-1), was evaluated in the CI ELISA. Recombinant EMA-1 bound antibody from the sera of B. equi-infected horses from 18 countries. The antibody response to EMA-1 was then measured in horses experimentally infected with B. equi via transmission by the tick vector Boophilus microplus or by intravenous inoculation. Anti-EMA-1 antibody was detected 7 weeks post-tick exposure and remained, without reexposure to B. equi, for the 33 weeks of the evaluation period. The data indicate that recombinant EMA-1 can be used in the CI ELISA to detect horses infected with B. equi.
Publication Date: 1992-12-11 PubMed ID: 1280648PubMed Central: PMC270599DOI: 10.1128/jcm.30.12.3122-3126.1992Google Scholar: Lookup
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  • Journal Article
  • Research Support
  • U.S. Gov't
  • Non-P.H.S.

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 focuses on identifying horses infected with Babesia equi using antibodies linked with a protein epitope from the parasite. The team developed a new method to detect these antibodies using cloned genes expressing the protein epitope in a lab-grown bacteria strain.

Understanding the Research

  • The study is focused on identifying horses infected with Babesia equi, a blood parasite that causes equine piroplasmosis, a significant disease affecting horses worldwide. The identification is done by looking for antibodies in the horse that react with a specific protein (or epitope) on the surface of the parasite.
  • The researchers had previously shown the presence of these antibodies using a method called Competitive Inhibition Enzyme-Linked Immunosorbent Assay (CI ELISA). Here, a monoclonal antibody, 36/133.97, which can bind to the specific protein epitope on the parasite surface, is used to detect the presence of similar antibodies in the horse serum. If antibodies are present in horse serum, there will be competition to bind to the epitope, reducing the amount of 36/133.97 binding, indicating an infection.

The Approach

  • The team cloned the gene that encodes the specific B. equi merozoite epitope and expressed it in a common laboratory strain of bacteria, Escherichia coli. This approach allows researchers to produce large amounts of the epitope, now named equi merozoite antigen 1 (EMA-1), for further analysis.
  • When tested in the CI ELISA method, this recombinant EMA-1 was able to detect antibodies in the serum from infected horses worldwide, proving its efficiency and broad utility.

Findings

  • The research team further tested this method in horses that were infected experimentally either via the tick vector Boophilus microplus or by blood injection.
  • The antibody response to the EMA-1 protein could be detected as early as 7 weeks after exposure and persisted for 33 weeks without recurring exposure to the parasite. This validates EMA-1 as a useful marker for tracking the infection’s progression and potentially the efficacy of treatments.
  • The study concluded that the recombinant EMA-1 can be effectively used in the CI ELISA method to detect horses infected with B. equi. This might present an improved method for diagnosing infection with this important pathogen and thus contribute to its control.

Cite This Article

APA
Knowles DP, Kappmeyer LS, Stiller D, Hennager SG, Perryman LE. (1992). Antibody to a recombinant merozoite protein epitope identifies horses infected with Babesia equi. J Clin Microbiol, 30(12), 3122-3126. https://doi.org/10.1128/jcm.30.12.3122-3126.1992

Publication

ISSN: 0095-1137
NlmUniqueID: 7505564
Country: United States
Language: English
Volume: 30
Issue: 12
Pages: 3122-3126

Researcher Affiliations

Knowles, D P
  • Animal Disease Research Unit, U.S. Department of Agriculture, Pullman, Washington 99164-7030.
Kappmeyer, L S
    Stiller, D
      Hennager, S G
        Perryman, L E

          MeSH Terms

          • Animals
          • Antibodies, Protozoan / blood
          • Antigens, Protozoan
          • Babesia / immunology
          • Babesiosis / diagnosis
          • Babesiosis / immunology
          • Enzyme-Linked Immunosorbent Assay
          • Epitopes
          • Evaluation Studies as Topic
          • Horse Diseases / diagnosis
          • Horse Diseases / immunology
          • Horses
          • Protozoan Proteins / immunology
          • Recombinant Proteins / immunology
          • Time Factors

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