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Psoroptes ovis ‐Early Immunoreactive Protein (Pso‐EIP‐1) a novel diagnostic antigen for sheep scab
Author(s) -
Burgess Stewart T. G.,
Nunn Francesca,
Bartley Kath,
Frew David,
McLean Kevin,
Inglis Neil F.,
McGeachy Kara,
Taliansky Michael E.,
Love Andrew J.,
Nisbet Andrew J.
Publication year - 2020
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1111/pim.12788
Subject(s) - ovis , antigen , biology , epitope , recombinant dna , virology , diva , serology , immunogenicity , immunology , antibody , gene , genetics , ecology
Aims Serodiagnosis of sheep scab is an established diagnostic method and has become popular in recent years. However, the current diagnostic antigen, Pso o 2, has shown promise as a component of a recombinant vaccine for scab, making it incompatible with discriminating between infected and vaccinated animals (DIVA). Here, we describe the discovery and characterization of a novel Psoroptes ovis immunodiagnostic antigen, P. ovis ‐Early Immunoreactive Protein‐1 (Pso‐EIP‐1). Methods and Results Pso‐EIP‐1 is a highly abundant member of a six‐gene family with no known homologs, indicating its potential uniqueness to P. ovis . Expression of recombinant Pso‐EIP‐1 (rPso‐EIP‐1) required a C‐terminal fusion protein for stability and specific IgG immunoreactivity against rPso‐EIP‐1 was observed in sheep serum from 1 to 2 weeks post‐infestation, indicating its highly immunogenic nature. Two of the three in silico‐predicted B‐cell epitopes of Pso‐EIP‐1 were confirmed by in vitro epitope mapping and, in a direct comparison by ELISA, Pso‐EIP‐1 performed to the same levels as Pso o 2 in terms of sensitivity, specificity and ability to diagnose P. ovis on sheep within 2 weeks of infestation. Conclusion Pso‐EIP‐1 represents a novel diagnostic antigen for sheep scab with comparable levels of sensitivity and specificity to the existing Pso o 2 antigen.