Yu Ziding, Ren Hang, Sun Mengxu, Xie Wanying, Sun Songsong, Liang Ning, Wang Haijian, Ying Xiaoqiang, Sun Yuxi, Wang Yuling, Zheng Yunping, Hu Xueying, Su Jingliang
Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China.
College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
Transbound Emerg Dis. 2022 Jul;69(4):e1130-e1141. doi: 10.1111/tbed.14402. Epub 2021 Dec 13.
Tembusu virus (TMUV) associated disease is a growing cause of egg production decrease and encephalitis in domestic waterfowl, with expanding distribution. In previous studies, TMUV isolates were phylogenetically classified into two genetic lineages and different clusters with varied pathogenicity. However, little is known about the phenotypic and virulence characteristics of cluster 3 isolates within the duck TMUV lineage. In this study, the etiological agent causing egg drop in a laying chicken farm in southern China was investigated and a TMUV was isolated from pooled tissue samples. Genome sequencing and phylogenetic analysis grouped the isolate into TMUV cluster 3 with closest relation to the mosquito-origin TMUV YN12193. Cross-neutralization testing using convalescent sera revealed significant antigenic variation between the isolate and a representative strain of cluster 2.2. The experimental infection of SPF hens confirmed the ability of the isolate to replicate in multiple tissues and led to ovary damage. Additionally, high seroconversion rates (95.83%-100%) were detected in the three flocks following retrospective investigation. Our study demonstrates the occurrence of cluster 3 TMUV infection in laying chickens and that the virus exhibits significant antigenic variation compared with cluster 2 TMUV.
坦布苏病毒（TMUV）相关疾病是导致家鸭产蛋量下降和脑炎的一个日益严重的原因，其分布范围不断扩大。在以往的研究中，TMUV分离株在系统发育上被分为两个遗传谱系和具有不同致病性的不同簇。然而，关于鸭TMUV谱系中第3簇分离株的表型和毒力特征知之甚少。在本研究中，对中国南方一个蛋鸡场导致产蛋下降的病原体进行了调查，并从混合组织样本中分离出一株TMUV。基因组测序和系统发育分析将该分离株归入TMUV第3簇，与蚊源TMUV YN12193关系最为密切。使用恢复期血清进行的交叉中和试验显示，该分离株与第2.2簇的一个代表性菌株之间存在显著的抗原变异。对SPF母鸡进行的实验性感染证实了该分离株在多个组织中复制的能力，并导致卵巢损伤。此外，在回顾性调查后的三个鸡群中检测到高血清转化率（95.83%-100%）。我们的研究证明了第3簇TMUV在蛋鸡中的感染情况，并且该病毒与第2簇TMUV相比表现出显著的抗原变异。
