作　　者： (倪杰）; (孟宪臣）; (李芙蓉）; (谢静）; (陆广富）; (朱春红）; (陈凯）; (孟霞）; (朱国强）;

机构地区： 扬州大学兽医学院,江苏扬州225009 江苏省动物重要疫病与人兽共患病防控协同创新中心,江苏扬州225009

出　　处： 《中国兽医学报》 2017年第9期1687-1692,共6页

摘　　要： RyhB是一种大小为90bp左右的细菌非编码小RNA,已有研究表明存在于鼠伤寒沙门菌和霍乱弧菌中的2种RyhB同源物RyhB-1和IsrE可调控细菌生物膜形成、趋化性和耐酸性。为研究RyhB在肠炎沙门菌致病性上的作用,以及2种同源物能否对毒力调控发挥协同作用,本试验利用λ-Red同源重组系统构建了ryhB-1和isrE单、双缺失株,利用表达载体pBR322和pACYC184分别构建了回补质粒并导入缺失株50336△ryhB-1,50336△isrE,50336△ryhB-1/△isrE中,获得各突变株相应的回补菌株,检测了野生株和各突变株对1日龄雏鸡半数致死量(LD50)、致死率、体内分布等致病性差异。结果发现,ryhB-1和isrE基因缺失后导致肠炎沙门菌毒力减弱,双基因缺失株毒力下降更为明显,表明2种小RNA均对肠炎沙门菌致病性具有增强作用,且二者对毒力的调控具有协同作用。 RyhB is a kind of about 90 bp bacterial non-coding small RNA. It was reported that two RyhB homologs RyhB-1 and IsrE,whieb existed in the Salmonella typhirnurium and Vibrio chol- erae could regulate biofilm formation, chemotaxis and acid resistance. To study the pathogenicity and cooperative function of RyhB-1 and IsrE, we constructed ryhB-1 and isrE single and double deletion mutants by the X-Red-based recombination system and corresponding complemented mu- tants by constructing complemented plasmid with pBR322 and pACYC184,and transferring to de- letion mutants 50336△ryhB-1,50336△isrE and 50336△ryhB-1/△isrE. Then we tested the path- ogenic differences of wild type,ryhB-1 and isrE deletion mutants and complemented mutants by inoculating above strains to 1-day-old chickens and detecting LD56, mortality rate and bacterial dis- tribution in chickens. The results showed that the virulence of Salrnonella enteritidis was de- creased in the ryhB-1 or isrE gene deletion strain,especially in ryhB-1 and isrE double deletionstrain. It indicated that ryhB-1 and isrE gene could enhance pathogenicity of Salmonella enteriti dis. The two sRNAs have a cooperative effect in virulence regulation.

关 键 词： 肠炎沙门菌 半数致死量 致病性