Enzyme-linked immunosorbent assay and agar gel immunodiffusion assay for diagnosis of equine infectious anemia employing p26 protein fused to the maltose-binding protein
A codon-optimized equine infectious anemia virus p26 gene was fused to a maltose-binding protein (MBP) and expressed in Escherichia coli for use as an antigen in agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent assay (ELISA) for diagnosis of equine infectious anemia. An analysis of analytical sensitivity and specificity showed that the antigen MBP-p26rec reacted positively with a reference World Organization for Animal Health serum and demonstrated no cross-reaction against sera from vaccinated animals in either test. The diagnostic characteristics were evaluated and presented excellent values. The AGIDrec showed 100% sensitivity and specificity, and the ELISArec showed 100% sensitivity and 99.64% specificity. In addition, MBP-p26rec was stabile after three years of storage at 4 °C, maintaining its immunoreactivity.
This work was funded by the Foundation for Science and Technology Support of the State of Pernambuco (FACEPE), the Financier of Studies and Projects (FINEP), and Biovetech (PAPPE - 2008; Proc APS 0338-5.05/08). Scholarships were awarded by the Brazilian agencies CAPES and CNPq. The authors are grateful to Dr. Hans Aymeric from Equine Diseases Laboratory (Maisons-Alfort, France) for kindly providing the OIE anti-EIAV reference serum, and to the Brazilian Ministry of Agriculture, Livestock and Supply for permission to import the serum.
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Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
All authors have seen and agree with the contents of the manuscript.
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