Novel purification method for recombinant 3AB1 nonstructural protein of foot-and-mouth disease virus for use in differentiation between infected and vaccinated animals.
An indirect enzyme-linked immunosorbent assay (ELISA) was developed for differentiation of animals infected with foot-and-mouth disease virus (FMDV) from vaccinated animals. The test was based on a highly pure and concentrated preparation of recombinant 3AB1 protein obtained by expression in a prokaryotic system, protein separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and electro elution. Experimental- and field-serum samples from naive, vaccinated, and infected cattle were tested for anti3AB1 antibody using the ELISA. A cutoff level was set at 35% of the maximum absorbance obtained with a positive control serum (FMDV-infected animal, 21 days postinfection [dpi]). This assay could detect antibodies from sera of animals experimentally infected by contact (n = 118) with a sensitivity of 97.5%. The specificity was 100%, based on negative test results obtained on 109 sera from naive animals. Remarkably, all sera from animals vaccinated either once (n = 102) or twice (n = 30) were negative. In addition, this 3AB1-ELISA could detect seroconversion at 7 dpi in animals inoculated intradermolingually. This assay constitutes an important tool for the rapid detection of FMDV outbreaks in a vaccinated population. In addition, it presents a reliable, economical, and simple method for testing large numbers of serum samples.
Nanni
Mariana
M
Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICV), (INTA)-Castelar, Los Reseros y Las Cabañas, 1712 Buenos Aires, Argentina.
Alegre
Mariana
M
Compaired
Diego
D
Taboga
Oscar
O
Fondevila
Norberto
N
D000818:Animals; D000956:Antigens, Viral / Q000302:isolation & purification*; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005536:Foot-and-Mouth Disease / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology*; D008297:Male; D011994:Recombinant Proteins / Q000302:isolation & purification; D017361:Viral Nonstructural Proteins / Q000302:isolation & purification*; D014765:Viral Vaccines
D000956:Antigens, Viral; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; D014765:Viral Vaccines