State Key Laboratory of Bioreactor Engineering，East China University of Science and Technology, Shanghai, P.R. China.
Department of Applied Biology, East China University of Science and Technology, Shanghai, P.R. China.
J Microbiol Biotechnol. 2019 Aug 28;29(8):1273-1280. doi: 10.4014/jmb.1904.04023.
is the causative agent of edwardsiellosis, which has caused enormous economic losses worldwide. In our previous research, an attenuated live vaccine WED based on the virulent strain EIB202 can effectively protect turbots against edwardsiellosis via intraperitoneal injection, while vaccination by immersion exhibits a weaker effect. During the development of the immersion vaccine, we surprisingly found the counts of ΔpEIB202/ EIB202 colonized on zebrafish were 100 times lower than those of EIB202. However, pEIB202 carries 53 predicted ORFs and has several copies in EIB202, impeding the study of its function. Thus the replication region is located at a 1 980 bp fragment (from 18 837 to 20 816 bp), containing a transcriptional repressor and a replication protein. Moreover, the minimal replication plasmid, named pRep-q77, has low copies in both and , but is more stable in than in . This work lays a foundation for further examination of the function of the virulence plasmid pEIB202.
是爱德华氏菌病的病原体，已在全球范围内造成巨大的经济损失。在我们之前的研究中，一种基于强毒株 EIB202 的减毒活疫苗 WED 通过腹腔注射能有效保护大菱鲆免受爱德华氏菌病的侵害，而浸泡式接种的效果则较弱。在研制浸泡疫苗的过程中，我们惊奇地发现，与 EIB202 相比，ΔpEIB202/ EIB202 在斑马鱼上的定植数量低了 100 倍。然而，pEIB202 携带 53 个预测的 ORFs，在 EIB202 中有多个拷贝，这阻碍了其功能的研究。因此，复制区位于一个 1980bp 的片段（从 18837 到 20816bp）中，包含一个转录抑制剂和一个复制蛋白。此外，最小复制质粒，命名为 pRep-q77，在和 中拷贝数较低，但在 中比在 中更稳定。这项工作为进一步研究毒力质粒 pEIB202 的功能奠定了基础。
