Researchers from the National Animal and Plant Quarantine Agency in South Korea developed and validated a new recombinant protein-based ELISA for detecting antibodies to foot-and-mouth disease virus type O. They tested the ELISA on over 1,700 field sera samples from cattle and pigs, as well as international reference sera, and found it had an overall diagnostic specificity of 99.9% and sensitivity of 95.2%. The recombinant protein used in the ELISA was derived from a baculovirus-expressed FMDV type O strain. The ELISA demonstrated high serotype specificity, reproducibility, and stability, making it a useful new tool for foot-and-mouth disease surveillance and control.

1. 1EuFMD | Open Session special edition | #OS20se
National Animal and Plant Quarantine Agency / Republic of Korea
VALIDATION OF RECOMBINANT
PROTEIN-BASED ELISA FOR DETECTION
OF ANTIBODIES TO FOOT-AND-MOUTH
DISEASE VIRUS TYPE-O
Eun-Jin Choi (Presenter), YouJin Han, JiHyun Lee, Hyun Mi Pyo,
Doheon Gwon, Wonseok Shin, JaeMyoung Kim and Mi-Young Park

2. 2EuFMD | Open Session special edition | #OS20se
 The ELISA (r-SPCE) kit has been developed and validated with
field sera collected from either vaccinated or non-vaccinated
from non-infected cattle and pig farms, international reference
sera obtained from WRLFMD, Pirbright and sera from
experimentally challenged animals.
 The recombinant protein (rP13C) was derived from
recombinant VP4231 protein of FMDV O/JC/SKR/2014
(O/SEA/Mya98) genes using a baculovirus-expressed system.
Main Idea

3. 3EuFMD | Open Session special edition | #OS20se
 The overall diagnostic specificity of 99.9% with a threshold of 50%
inhibition was identified by analyzing 1,070 cattle and 730 pigs from
FMD-free and non-vaccinated country (Canada, USA).
 Diagnostic sensitivity estimated using 475 known positive animal sera
result of 95.2%.
 International reference sera were correctly detected.
 A high level of serotype-specificity was demonstrated testing
IAEA/FAO standard sera strongly positive against other FMDV
serotypes.
 Also, the CV obtained for evaluating reproducibility and repeatability
estimated ≤10%, demonstrating the excellent stability of the ELISA (r-
SPCE).

4. 4EuFMD | Open Session special edition | #OS20se
 Objectives
- A new recombinant protein-based solid-phase competitive ELISA(r-
SPCE) with monoclonal antibody (Mab) for detection of antibodies to
FMDV type-O and has been developed and validated with field sera
and international reference sera.
 Outcomes
- The recombinant protein-based SPCE developed for the detection of
antibodies to FMDV type-O demonstrated high specificity and
sensitivity. In addition, this assay offers advantages in terms of
repeatability and broader cross-specificity, but also is easy-to use
and applicable to multiple species.

5. eufmdvirtual.com
8, 10, 15, 17 December 2020
EuFMD / Open Session