期刊论文

中文

中国兽医学报

1005-4545

2009

29

10

1293-1298

10.16303/j.cnki.1005-4545.2009.10.015

国家重点基础研究发展计划（“973”计划）资助项目（2006CB504404）；

本校为第一机构

扩增了srtA基因的上、下游同源臂P1和P2及其全长序列,利用温度敏感型"自杀性"质粒pSET4s构建了重组质粒pSET4s-P1-P2,并将该质粒电转化入野生菌株SS2(SC21)中,通过抗生素和温度双重筛选,得到srtA基因缺失菌株,命名SC211.同时,将srtA基因定向插入穿梭质粒pAT18,构建穿梭质粒pAT18-srtA,并将该质粒电转入srtA基因缺失菌株SC211中,通过抗生素筛选,得到质粒介导的srtA基因互补菌株SC212.通过PCR、South-ern blotting等对缺失突变菌株和互补菌株进行了鉴定.对基因缺失突变菌株和回复菌株传代培养遗传稳定性试验结果显示,缺失突变菌株和互补菌株能够稳定遗传.比较了基因缺失突变菌株、互补菌株及野生菌...

In the present study, srtA gene mutant strain was constructed by using the thermo-sensitive suicide vector pSET4s and confirmed by PCR and Southern blotting. The results showed that the construction of the mutant strain was successful, named SC211. In addition complementation mutant strain was constructed by using the E. coli/ Streptococcus shuttle vector pAT18, named SC212. The characteristic of SC211 and SC212 was further researched. The virulence of different strains was determined by animal infection,which demonstrated that the virulence was decreased clearly when the srtA gene knocked out...