El Damaty Hend M, Fawzi Elshaima M, Neamat-Allah Ahmed N F, Elsohaby Ibrahim, Abdallah Abdelmonem, Farag Gamelat K, El-Shazly Yousry A, Mahmmod Yasser S
Infectious Diseases, Department of Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig City 44511, Egypt.
Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig City 44511, Egypt.
Animals (Basel). 2021 Jun 7;11(6):1697. doi: 10.3390/ani11061697.
Spontaneous mutations are a common characteristic of the foot and mouth disease virus (FMDV), leading to wide antigenic variations resulting in the emergence of new topotypes and lineages of FMDV, which contributes to occasional vaccination failures. The objectives of the present study were to genetically characterize FMDV isolated from water buffaloes and study the biochemical and histopathological indicators of infected animals. Fifty-four water buffaloes of both sexes and different ages suffered from acute symptoms of FMD were clinically examined and randomly selected for inclusion in this study. Oral desquamated epithelial and oropharyngeal fluid samples have been tested for FMDV by reverse transcriptase PCR (RT-PCR). Tissue and serum samples were also collected from the diseased buffaloes and subjected to histopathological and biochemical analysis. Our findings showed that all examined samples were confirmed to be positive to FMDV serotype SAT-2 and were adjusted to be responsible for the recent disease outbreak in this study. Phylogenetic analysis revealed that the circulating viruses were of the SAT-2 serotype, closely related to the lineage of lib12, topotype VII, with 98.9% identity. The new lineage of SAT-2 showed a high virulence resulting in the deaths of water buffaloes due to heart failure, confirmed by high serum levels of inflammatory and cardiac markers, including haptoglobin, ceruloplasmin, cardiac troponin I and creatine phosphokinase-MB, indicating an unfavorable FMD-infection prognosis. In conclusion, we document the presence of new incursions circulating in water buffalo populations in Egypt in early 2019, explaining the high morbidity rate of FMD outbreak in early 2019. Furthermore, the newly identified serotype SAT-2 lib12 lineage, topotype VII, showed an aggressive pattern in water buffaloes of the smallholder production system.
自发突变是口蹄疫病毒（FMDV）的一个常见特征，会导致广泛的抗原变异，从而产生FMDV的新拓扑型和谱系，这有时会导致疫苗接种失败。本研究的目的是对从水牛分离出的FMDV进行基因特征分析，并研究受感染动物的生化和组织病理学指标。对54头不同年龄和性别的出现口蹄疫急性症状的水牛进行了临床检查，并随机选择纳入本研究。通过逆转录聚合酶链反应（RT-PCR）对口咽脱落上皮和口咽液样本进行FMDV检测。还从患病水牛身上采集了组织和血清样本，并进行了组织病理学和生化分析。我们的研究结果表明，所有检测样本均被确认为FMDV血清型SAT-2阳性，并被认定为导致本研究中近期疾病爆发的原因。系统发育分析显示，流行病毒为SAT-2血清型，与lib12谱系、拓扑型VII密切相关，同源性为98.9%。SAT-2的新谱系显示出高毒力，导致水牛因心力衰竭死亡，高血清水平的炎症和心脏标志物，包括触珠蛋白、铜蓝蛋白、心肌肌钙蛋白I和肌酸磷酸激酶-MB证实了这一点，表明FMD感染预后不佳。总之，我们记录了2019年初在埃及水牛群体中存在新的流行毒株，解释了2019年初FMD爆发的高发病率。此外，新鉴定的血清型SAT-2 lib12谱系、拓扑型VII在小农生产系统的水牛中表现出侵袭性模式。
