猪链球菌ssnA基因缺失突变菌株的构建及毒力分析

发布时间：2018-03-08 17:50

本文选题：猪链球菌型　切入点：ssnA基因　出处：《华北农学报》2017年04期 　论文类型：期刊论文

【摘要】：分泌型核酸酶基因ssnA是近年来研究发现的一种脱氧核糖核酸酶,被认为是一种猪链球菌2型(SS2)潜在的毒力因子。为了分析ssnA基因对于SS2毒力的影响,通过体外构建具有同源臂的重组自杀性质粒,电转化进入SS2,经同源重组构建了SS2流行毒力株GD01的ssnA基因缺失突变菌株,并通过比较分析了野生菌株与缺失突变菌株的生长特性及溶血活性等生物学特性。结果显示,GD01株与ΔssnA突变株的生长速度及溶血活性没有明显差异;ssnA基因缺失后SS2对Hep-2细胞的黏附及入侵能力则明显下降。小鼠毒力试验结果显示,ssnA基因缺失突变菌株对于CD1小鼠LD50是6.17×108cfu,而SS2野生菌株的LD50是4.42×107cfu,缺失突变株的LD50约是野生株的14倍,表明ssnA的缺失对SS2毒力产生明显影响,提示ssnA基因在其致病过程中具有重要作用,其具体作用机制需进一步分析。
[Abstract]:Secretory nuclease gene ssnA is a deoxyribonuclease found in recent years, which is considered as a potential virulence factor of Streptococcus suis type 2 (SS2). In order to analyze the effect of ssnA gene on the virulence of SS2. The recombinant suicide plasmid with homologous arm was constructed in vitro and electrotransformed into SS2. The ssnA gene deletion mutant strain of SS2 virulent strain GD01 was constructed by homologous recombination. The growth and hemolytic activity of wild strain and deletion mutant strain were compared and analyzed. The results showed that there was no significant difference in growth rate and hemolytic activity between GD01 strain and 螖 ssnA mutant. The results of mouse virulence test showed that the mutagenesis of Hep-2 gene was 6.17 脳 108cfu. the LD50 of SS2 wild strain was 4.42 脳 107cfu. the LD50 of the mutant was about 14 times as high as that of the wild strain. The results suggest that the absence of ssnA has a significant effect on the virulence of SS2, suggesting that ssnA gene plays an important role in the pathogenesis of SS2, and its specific mechanism needs further analysis.
【作者单位】：广东省农业科学院动物卫生研究所;广东省畜禽疫病防治研究重点实验室;广东省兽医公共卫生公共实验室;
【基金】：广州市科技计划项目(201510010142) 广东省科技计划项目(2016B020202004) 广东省公益研究与能力建设专项资金(2014B070706011) 广东省国际合作项目(2015B050501007)
【分类号】：S852.611

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