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

Abstract

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. Monitoring of FMDV in neighboring countries is essential to predict those strains that might escape into Egypt.

Isolation and Molecular Characterization of Circulating Foot and Mouth Disease Virus in Egypt During 2018-2020

“…6 to 10) with other isolates in the database indicated that the detected strain is closely related to SAT-2/LIB/41/2012, SAT-2, Ismailia/1.2.3/2018 which belong to topotype VII and other Egyptian isolates published during 2018, these results in alignment with the findings of Soltan et al (2019) who expected that Egyptian outbreaks of FMDV SAT2 during the period of 2018 -2019 may be originated from Libya. Also, these results in close agreement with the findings of Hagag et al (2019) who detected that FMD SAT2 circulated in Egypt in 2018-2019 and reported reemergence of FMD serotype O Manisa in Egyptian cattle in 2019.…”

Genetic characterization and phylogenetic analysis of foot and mouth disease virus vaccine strains and recent field isolate

“…The relationship between the FMDV circulating strains in Egypt and vaccine strains (5,6,9,34,(38)(39)(40)(41). A-FMDV circulating strains within serotype A: (1-Topotype Africa G-VII and G-IV&2-Topotype Asia, lineage Iran-05).…”

“…Since 1958, Egypt has been regarded as one of the African countries endemic to the FMD virus (4). In 2018, a severe FMD outbreak was reported by farmers and veterinarians' complaints about severe losses in water buffalo and young animals, Heavy studies were performed for virus isolation, and genetic characterization revealed that newly circulating FMDV relates to serotype SAT-2 topotype VII, lineage lib-12 and confirmed a sequence variance from the vaccine strain (5)(6)(7)(8). An emergency inactivated monovalent vaccine was manufactured by Veterinary Serum and Vaccine Research Institute and the Middle East for Veterinary vaccines (ME-VAC) and evaluated by the Central Laboratory for Evaluation of Veterinary Biologics (CLEVB) using serotyping ELISA and 146S antigenic content (9,10).…”