Molecular and Genetic Characterization of Newly Circulating Foot and Mouth Disease Virus (FMDV) Serotype SAT2 in Egypt during 2018 and Early 2019

Foot and mouth disease virus (FMDV) is a severe, highly contagious, and economically devastating viral disease worldwide.FMDV affects animals with cloven hooves, including domestic and wild bovids.In this study, 100 FMDV field samples were collected in 2018 and early2019 from governorates in Egypt.Molecular and genetic characterization indicates that serotype SAT2 is widespread (in 96 cases), while only four cases of Serotype O were detected.Phylogenetic analysis of the study sequences indicates that the circulating FMDV serotype SAT2 viruses were homogeneous and related to Topotype VII.Importantly, the newly emerged viruses were closely related to strains isolated from Libya in 2012 (Topotype VII, lineage 3), with 92-93% amino acid identity, and were clearly separated from SAT2/GVII/Gharbia/Egy/2012 and SAT2/GVII/ Alex/Egy/2012 (Topotype VII, lineage 2), indicating a new introduction of FMDV serotypeSAT2 in Egypt.Moreover, the high antigenic variation in FMDV is recognized as a major problem in vaccination.Because the vaccine strains should match those strains circulating in the field, an updated vaccine is required to control the disease.