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
Clinical and vaccine immunology, Vol.20(11), pp.1752-1757
11/2013
:
https://hdl.handle.net/2376/101096
: PMC3837787
: 24049108
Tick-borne pathogens that cause persistent infection are of major concern to the livestock industry because of transmission risk from persistently infected animals and the potential economic losses they pose. The recent reemergence of
Theileria equi
in the United States prompted a widespread national survey resulting in identification of limited distribution of equine piroplasmosis (EP) in the U.S. horse population. This program identified
Babesia caballi
-seropositive horses using rhoptry-associated protein 1 (RAP-1)–competitive enzyme-linked immunosorbent assay (cELISA), despite
B. caballi
being considered nonendemic on the U.S. mainland. The purpose of the present study was to evaluate the suitability of RAP-1–cELISA as a single serological test to determine the infection status of
B. caballi
in U.S. horses. Immunoblotting indicated that sera from U.S. horses reacted with
B. caballi
lysate and purified
B. caballi
RAP-1 protein. Antibody reactivity to
B. caballi
lysate was exclusively directed against a single ∼50-kDa band corresponding to a native
B. caballi
RAP-1 protein. In contrast, sera from experimentally and naturally infected horses from regions where
B. caballi
is endemic bound multiple proteins ranging from 30 to 50 kDa. Dilutions of sera from U.S. horses positive by cELISA revealed low levels of antibodies, while sera from horses experimentally infected with
B. caballi
and from areas where
B. caballi
is endemic had comparatively high antibody levels. Finally, blood transfer from seropositive U.S. horses into naive horses demonstrated no evidence of
B. caballi
transmission, confirming that antibody reactivity in cELISA-positive U.S. horses was not consistent with infection. Therefore, we conclude that a combination of cELISA and immunoblotting is required for the accurate serodiagnosis of
B. caballi
.
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- 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
- Peter O Awinda - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USARobert H Mealey - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USALaura B. A Williams - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USAPatricia A Conrad - Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USAAndrea E Packham - Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USAKathryn E Reif - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USAJuanita F Grause - Animal and Plant Health Inspection Service, Veterinary Services, National Veterinary Services Laboratories, Ames, Iowa, USAAngela M Pelzel-McCluskey - U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Western Regional Office, Fort Collins, Colorado, USAChungwon Chung - Washington State University, Department of Veterinary Microbiology and PathologyReginaldo G Bastos - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USALowell S Kappmeyer - Animal Diseases Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, Washington, USADaniel K Howe - Department of Veterinary Science, M. H. Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, USASallyAnne L Ness - Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USADonald P Knowles - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USAMassaro W Ueti - Animal Diseases Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, Washington, USA
- Clinical and vaccine immunology, Vol.20(11), pp.1752-1757
- Department of Veterinary Microbiology and Pathology; Washington Animal Disease Diagnostic Laboratory; Department of Veterinary Clinical Sciences; Paul G. Allen School for Global Animal Health
- American Society for Microbiology; 1752 N St., N.W., Washington, DC
- 99900546519301842
- English
- Journal article