摘要
为构建能稳定携带外源基因的减毒鼠伤寒沙门菌ΔcrpΔcyaΔasdSL1344,本研究在减毒鼠伤寒沙门菌ΔcrpΔcyaSL1344基础上,以χ7213(pREΔasd)为供体菌,ΔcrpΔcyaSL1344为受体菌,利用自杀性质粒介导的等位交换技术成功筛选出缺失编码天冬氨酸β-半乳糖脱氢酶基因(aspartic semialdehyde dehydrogenase,asd)的ΔcrpΔcyaΔasdSL1344菌株,进一步对其生物学特性进行初步研究。结果显示,其血清型和亲本株ΔcrpΔcyaSL1344及强毒株SL1344相同且该缺失菌株能稳定遗传缺失后的asd基因;其生化特性和生长速度与强毒株SL1344相比有很大差异,与亲本株ΔcrpΔcyaSL1344基本一致,ΔcrpΔcyaΔasdSL1344失去了利用麦芽糖、乳糖、山梨醇等碳源的能力,也不能分解H2S、半乳糖和鼠李糖,但仍保留了利用葡萄糖的能力,其生长速度比强毒株更加缓慢。1日龄雏鸡攻毒试验表明ΔcrpΔcyaΔasdSL1344互补携带asd基因的pYA3493质粒后,ΔcrpΔcyaΔasdSL1344(pYA3493)毒力较强毒株SL1344降低了至少105倍,与亲本株ΔcrpΔcyaSL1344相比毒力仅相差10倍。结果表明,减毒鼠伤寒沙门菌ΔcrpΔcyaΔasdSL1344菌株构建成功,为深入研究以鼠伤寒沙门菌为载体的口服多价疫苗奠定基础。
To devep a live vaccine vector of Salmonella typhinurium, the △crp△cya△asdSL1344 strain was constructed by deletion of ecoding aspartic acid beta galaetose dehydrogenase （asd） gene from △crp△cyaSL1344 strain through the method of the transduetion of recombinant suicide plasmid. Then, the biological characteristics of △crp△cya△asdSL1344 strain were analyzed. The results showed that the mutant was stabile with the recombinant Aasd gene in vitro;The serotype of AcrpAcyaAasdSL1344 strain was identical with the parent △crp△cyaSL1344 strain and wild SL1344 strain;the growth rate of the mutant was almost same as the parent AcrpAcyaSL1344 strain,but more slowly than virulent AcrpAcyaSL1344 strain; the AcrpAcyaAasdSL1344 mutant was not able to ferment maltose,lactose,and sorbitol. It also had no ability to decompose H2S,galactose and rat lee sugar; The one-day-old chicken lethal test showed that △crp△cya△asdSL1344 （pYA3493） mutant was only 10 times lower than AcrpAcyaSL1344 strain, but at least 105 times lower than wild SL1344 strain. These results showed that the AcrpAcyaAasdSL1344 mutant was successfully constructed. It is likely that this mutant should be used as a live vector to express foreign genes.
出处
《中国兽医学报》
CAS
CSCD
北大核心
2014年第11期1758-1763,1769,共7页
Chinese Journal of Veterinary Science
基金
河南省科技攻关项目(112102110091)
作者简介
胡宁（1988-），女，硕士研究生。
通讯作者，E—mail：chengxch@126．com
