Studies on protective efficacy and safety of Brucella abortus ATP/GTP binding protein gene deleted mutant | 流产布鲁氏菌ATP/GTP结合蛋白基因缺失株保护力及安全性研究

Chinese. 为筛选具有诊断标记的布鲁氏菌病疫苗菌株,本研究利用同源重组和负筛选技术,构建了流产布鲁氏菌株2 308的ATP/GTP结合蛋白基因缺失株BDA14,并通过菌落染色和凝集特性,培养传代,小鼠接种试验及怀孕羊攻毒试验对其生物学特性、安全性和免疫效果进行了研究。结果表明：1）缺失菌株BDA14为粗糙型菌株,体外培养传代表型不发生改变;2）缺失菌株BDA14在小鼠体内的毒力与亲本菌株2308相比显著降低,且不产生针对OPS（O-antigen）的抗体;3）缺失菌株BDA14可提供与疫苗株RB51相当的攻毒保护力;4）缺失菌株BDA14对怀孕靶动物的安全性显著提高,接种怀孕羊不引起流产。说明ATP/GTP结合蛋白基因缺失株BDA14作为安全、有效且能鉴别诊断的疫苗菌株有明显优势。

English. Using homologous recombination and negative screening techniques,we constructed ATP/GTP binding protein gene deletion mutant which was named as BDA14 of B.abortus 2308 and studied the biological characteristics,safety,and induced protective immunity by staining and agglutination properties of colonies,passage stability test,mice inoculation assay,and pregnant sheep and goat challenge study.Study results showed that：1） The mutant BDA14 is rough-strain,and the phenotype of BDA14 did not changed after 20 consecutive passages in media;2） the mutant BDA14 was attenuated in virulence compared to its parent strain in mice model,and it did not induce antibodies against O-antigen;3） The mutant BDA14 can confer similar protection against challenges to vaccine strain RB51;4） The safety of BDA14 was significantly improved without induce abortion in pregnant sheep and goat.Therefore,The ATP/GTP binding protein gene deletion mutant BDA14 possess superiority acts as a safe,effective and differential diagnosis vaccine candidate,which is necessary to further study.