title: Development of an inactivated 3C(pro)-3ABC (mu3ABC) ELISA to differentiate cattle infected with foot and mouth disease virus from vaccinated cattle.
abstract: Foot and mouth disease, a highly contagious disease of cloven-hoofed animals, is still endemic in Asia, Africa, and a few countries in South America. Subclinical and persistent infections usually occur in vaccinated cattle exposed to FMDV. Successful control and eradication measures need a diagnostic assay that can distinguish between immune responses to infection and vaccination. The non-structural 3ABC ELISA is the most reliable differential diagnostic assay. However, expression of the native 3ABC gene in insect cells yielded truncated versions of the proteins; thus, a monoclonal antibody to capture digested proteins is needed to develop the assay. The purpose of this study was to develop a simple indirect 3ABC ELISA using complete 3ABC protein. The full-length mutated 3ABC protein with inactive 3C(pro) (mu3ABC) gene was constructed. The histidine-tagged mu3ABC protein was produced in insect cells for easy purification and measuring. This permits simple assay design and reproducible assay development. mu3ABC ELISA had diagnostic specificity and sensitivity of 96.6% and 84%, respectively, compared to Ceditest(®) FMDV-NS. Agreement of both assays was excellent with κ value of 0.823 (p<0.05). The mu3ABC ELISA could distinguish infected from vaccinated animals. These factors are necessary for the successful development of an in-house NSP-based ELISA. Availability of a reliable assay with acceptable costs would facilitate successful disease control and the establishment of disease-free zones. Expansion of such zones may ultimately decrease the risk of introducing FMDV into disease-free countries, thus accelerating global FMD control.
authors.affiliation: Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand.
authors.forename: Vasinee
authors.initials: V
authors.lastname: Srisombundit
authors.forename: Nattarat
authors.initials: N
authors.lastname: Tungthumniyom
authors.forename: Wilai
authors.initials: W
authors.lastname: Linchongsubongkoch
authors.forename: Chalermpol
authors.initials: C
authors.lastname: Lekcharoensuk
authors.forename: Ladawan
authors.initials: L
authors.lastname: Sariya
authors.forename: Pongrama
authors.initials: P
authors.lastname: Ramasoota
authors.forename: Porntippa
authors.initials: P
authors.lastname: Lekcharoensuk
mesh_terms: D000086042:3C Viral Proteases; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D003546:Cysteine Endopeptidases / Q000276:immunology*; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005536:Foot-and-Mouth Disease / Q000175:diagnosis*; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology*; D012680:Sensitivity and Specificity; D014730:Veterinary Medicine / Q000379:methods*; D017361:Viral Nonstructural Proteins / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology*
chemical_list: C109754:3ABC protein, virus; D000914:Antibodies, Viral; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins; D003546:Cysteine Endopeptidases; D000086042:3C Viral Proteases