Abstract:
Sheeppox, goatpox, and lumpy skin disease caused by the sheeppox virus (SPPV), goatpox virus (GTPV), and lumpy skin disease virus (LSDV), respectively, are diseases that affect millions of ruminants and many low-income households in endemic countries, leading to great economic losses for the ruminant industry. The three viruses are members of the Capripoxvirus genus of the Poxviridae family. Live attenuated vaccines remain the only efficient means for controlling capripox diseases. However, serological tools have not been available to differentiate infected from vaccinated animals (DIVA), though crucial for proper disease surveillance, control, and eradication efforts. We analysed the sequences of variola virus B22R homologue gene for SPPV, GTPV, and LSDV and observed significant differences between field and vaccine strains in all three capripoxvirus species, resulting in the truncation and absence of the B22R protein in major vaccines within each of the viral species. We selected and expressed a protein fragment present in wildtype viruses but absent in selected vaccine strains of all three species, taking advantage of these alterations in the B22R gene. An indirect ELISA (iELISA) developed using this protein fragment was evaluated on well-characterized sera from vaccinated, naturally and experimentally infected, and negative cattle and sheep. The developed wildtype-specific capripox DIVA iELISA showed >99% sensitivity and specificity for serum collected from animals infected with the wildtype virus. To the best of our knowledge, this is the first wildtype-specific, DIVA-capable iELISA for poxvirus diseases exploiting changes in nucleotide sequence alterations in vaccine strains.
摘要:
羊痘,山羊痘,和由羊痘病毒(SPPV)引起的块状皮肤病,山羊痘病毒(GTPV),和块状皮肤病病毒(LSDV),分别,是影响流行国家数百万反刍动物和许多低收入家庭的疾病,给反刍动物产业造成了巨大的经济损失。这三种病毒是Poxviridae家族的Capropoxvirus属的成员。减毒活疫苗仍然是控制羊痘疾病的唯一有效手段。然而,血清学工具尚未用于区分受感染的动物与接种疫苗的动物(DIVA),尽管对于正确的疾病监测至关重要,control,和根除努力。我们分析了SPPV的天花病毒B22R同源基因的序列,GTPV,和LSDV,并观察到所有三种羊痘病毒物种的田间和疫苗株之间的显着差异,导致每个病毒物种的主要疫苗中B22R蛋白的截短和缺失。我们选择并表达了存在于野生型病毒中但在所有三个物种的选定疫苗株中都不存在的蛋白质片段,利用B22R基因的这些改变。使用该蛋白质片段开发的间接ELISA(iELISA)在接种疫苗的特征明确的血清上进行了评估,自然和实验感染,和负牛羊。开发的野生型特异性羊痘DIVAiELISA对从感染野生型病毒的动物收集的血清显示>99%的灵敏度和特异性。据我们所知,这是第一个特定于野生型的,具有DIVA能力的iELISA用于痘病毒病,利用疫苗株中核苷酸序列改变的变化。