Circulating Mutant of Foot and Mouth Disease virus serotype A-African- Genotype IV in Egypt during 2022

Abstract

Foot and Mouth Disease Virus causes continuously annoying outbreaks and massive animal illnesses. Usually, the potential influence of the disease was due to the emergence of conquered emergent new strains or re-emergence of local strains with major antigenic variations due to the mutation in the genetic strip. Therefore, the proposed work is based on the genetic characterization of the virus by VP1 codon sequencing in the tested samples. Besides, the viral physiological testing using BHK-21 cell lines and the ELISA test for FMDV antigen serotyping. Positive serotype A samples were furtherly analyzed for nucleotide sequencing. The resulting sequences showed that they belonged to the FMD serotype A African topotypes originating from the ancestor prototype SUD/77 with a similarity of 98.48 ± 1.2% with each other. The divergence was 9.3% from the other local isolates from 2020. Additionally, they are closely related to the Egyptian-Damietta type-2016 and the Sudanese-2018 by 96.84 ± 1.01% and 95.84 ± 0.79%, respectively. Moreover, the divergence with the vaccinal strains ranged from 10 to 17%. Ultimately, the analysis of the amino acid showed that the isolates have variation in the most prominent antigenic regionsof of, allocated at residues 35–75, and at the immunogenic determinants of the G-H loop of VP1 (residues 100–146, residues 161–175). Therefore, the current isolates should be included in the vaccine to provide broader immunogenic coverages against serotype A-African topotypes.