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Abstract

The South African Territories (SAT) types of foot-and-mouth disease (FMD) virus show marked genomic and antigenic variation in sub-Saharan Africa that is to a large extent geographically determined. This has implications for selection of appropriate vaccine strains as well as the accuracy of laboratory diagnosis. However, adaptation of field isolates as vaccine strains is cumbersome, time consuming and expensive. We propose the construction of recombinant viruses in which specific antigenic determinants can be manipulated. To achieve this goal, the structural-protein-coding region of a SAT 2 vaccine strain, ZIM 7/83/2, was determined and compared with two other known SAT 2 P1 regions. Five hypervariable regions were identified of which four are situated within VP1. The cleavage sites for proteolytic processing differs from serotype A, while the junction between P1/2A is variable within the SAT 2 serotype. These differences could influence the construction of recombinant vaccines.

Reconstructing Geographical Movements and Host Species Transitions of Foot-and-Mouth Disease Virus Serotype SAT 2

“…This likely renders a naive whole-genome phylogenetic approach inadvisable. Indeed, van Rensburg et al (22) found that the leader and 3C proteinases of SAT FMDVs displayed branching patterns very different from those of VP1, and it is this recombination that likely explains the findings by Yoon et al (23) and Lewis-Rogers et al (24) that when a full-genome analysis is performed, the SAT strains do not form separate clades. However, while the entire genome may not be a good subject for analysis, future work could use the whole structural protein region, rather than just VP1.…”

Diagnostic and Epitope Mapping Potential of Single-Chain Antibody Fragments Against Foot-and-Mouth Disease Virus Serotypes A, SAT1, and SAT3

“…Both the solid-phase competition (SPCE) and LPBE ELISAs for SAT1, SAT2, and SAT3 are OIE recognized and well established assays. Considering the high genetic diversity of the SAT-type viruses ( 2 , 6 , 26 , 49 ), there is a continuous need for improvement of these assays as cross-reactivity has been noted with the SAT types using this assay. Additionally, for FMD vaccine matching where the antigenic variability of field virus strains is measured against current vaccine strains, the virus neutralization assay is utilized.…”

Sequence-Based Prediction for Vaccine Strain Selection and Identification of Antigenic Variability in Foot-and-Mouth Disease Virus

“…Viral RNA was extracted from cell-culture-adapted isolates and cDNA synthesised [36]. The sequences for the P1-2A-coding regions were obtained via RT-PCR of viral genomic RNA using existing primers [36]–[39]. Direct DNA sequencing of the P1-2A region derived from a given FMDV isolate yielded a master sequence representing the most probable nucleotide for each position of the sequence.…”