Lan Mo Zhao, Peng Xiao, Xiang Mao Yun, Xia Zou Yu, Bo Wang, Jie Li, Li Xu Yong, Jun Zhang Pei
Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China.
Fish Shellfish Immunol. 2007 Sep;23(3):521-30. doi: 10.1016/j.fsi.2006.11.002. Epub 2006 Nov 16.
The esrB gene of Edwardsiella tarda, which encodes a regulator protein of the type III secretion system, was mutated by the unmarked deletion method and reintroduced by allelic exchange into the chromosome of E. tarda LSE40 by means of the suicide vector pRE112. The LSE40 esrB mutant was highly attenuated when inoculated intraperitoneally into turbot Scophthamus maximus L., showing a 50% lethal dose of 10(8.1)cfu/fish. The esrB mutants were not recoverable from the internal organs at 14 days post-inoculation. Vaccination with a single dose of 10(5)-10(7) cfu/fish of the esrB mutant elicited significant protection against the wild-type strain of E. tarda LSE40 (relative percentage survival>50%). The protection correlated well with the antibody titres in the serum of vaccinated fish.
迟缓爱德华氏菌的esrB基因编码III型分泌系统的调节蛋白，采用无标记缺失法对其进行突变，并通过自杀载体pRE112利用等位基因交换将其重新导入迟缓爱德华氏菌LSE40的染色体中。将LSE40 esrB突变体腹腔接种到大菱鲆Scophthamus maximus L.中时高度减毒，其半数致死剂量为10(8.1) cfu/鱼。接种后14天，在内部器官中未检测到esrB突变体。用单剂量10(5)-10(7) cfu/鱼的esrB突变体进行疫苗接种可引发对迟缓爱德华氏菌LSE40野生型菌株的显著保护作用（相对存活率>50%）。这种保护作用与接种疫苗鱼血清中的抗体滴度密切相关。
