Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, 201306, UP, India.
National Veterinary Institute, POBox: 19, Bishoftu, Ethiopia.
Int Microbiol. 2022 Jan;25(1):47-59. doi: 10.1007/s10123-021-00178-w. Epub 2021 Jul 5.
Foot-and-mouth disease (FMD) is highly infectious, limits live animal trade, and affects ranchers owing to the loss of animal yield. The present study was designed to perform vaccine matching for field FMD virus isolates from clinically diseased cattle and assess the antigenic properties of the field isolates against the current vaccine strains used for vaccine production at the National Veterinary Institute, Ethiopia. Both sequencing and reverse transcription-polymerase chain reactions were used for distinguishing between the viral strains. To evaluate the serological relationship of the vaccine strain with these field isolates (r1 value), in vitro cross-neutralization was performed using ETH/6/2000 and ETH/38/2005 antisera. Infectious field FMD viral samples represented serotypes A and O. Sequence analysis showed that serotype A VP1/1D possessed amino acid variability at positions 28 and 42 to 48, 138, 141, 142, 148, 156, 173, and 197 compared with the ETH/6/2000 vaccine strain, whereas serotype O possessed amino acid variability at positions 45, 48, 138, 139, 140, 141, and 197 compared with the ETH/38/2005 vaccine strain. Based on the one-dimensional virus neutralization test, serotypes A and O demonstrated antigenic matching of up to 13/17 (76.47%) with the vaccine strain, except for the isolates ETH/40/2018, ETH/48/2018, ETH/55/2018, and ETH/61/2018, which had r-values less than 0.3. Therefore, the currently used vaccine strains ETH/38/2005 for serotype O and ETH/6/2000 for serotype A protected against all and most field viruses characterized as serotypes O and A, respectively, and amino acid residue variation was observed in different FMD virus B-C loops, G-H loops, and C-termini of VP1 at sites 1 and 3 in both serotypes.
口蹄疫（FMD）具有高度传染性，限制了活体动物贸易，并由于动物产量的损失而影响了牧场主。本研究旨在对来自临床患病牛的田间 FMD 病毒分离株进行疫苗匹配，并评估田间分离株对当前在埃塞俄比亚国家兽医研究所用于疫苗生产的疫苗株的抗原特性。本研究既使用测序也使用逆转录-聚合酶链反应来区分病毒株。为了评估疫苗株与这些田间分离株的血清学关系（r1 值），使用 ETH/6/2000 和 ETH/38/2005 抗血清进行了体外交叉中和试验。传染性田间 FMD 病毒样本代表了血清型 A 和 O。序列分析显示，血清型 A VP1/1D 在位置 28 和 42 到 48、138、141、142、148、156、173 和 197 处具有与 ETH/6/2000 疫苗株的氨基酸变异性，而血清型 O 在位置 45、48、138、139、140、141 和 197 处具有与 ETH/38/2005 疫苗株的氨基酸变异性。基于一维病毒中和试验，血清型 A 和 O 与疫苗株的抗原匹配度高达 13/17（76.47%），除了 ETH/40/2018、ETH/48/2018、ETH/55/2018 和 ETH/61/2018 这 4 个分离株之外，它们的 r 值小于 0.3。因此，目前用于血清型 O 的疫苗株 ETH/38/2005 和用于血清型 A 的疫苗株 ETH/6/2000 分别针对所有和大多数特征为血清型 O 和 A 的田间病毒提供了保护，并且在不同 FMD 病毒的 B-C 环、G-H 环和 VP1 的 C 末端 1 号和 3 号位点观察到氨基酸残基变异在两种血清型中。
