中国兽医科学2017，Vol.47Issue(9)：1087-1093,7.DOI:10.16656/j.issn.1673-4696.2017.09.003
鼠伤寒沙门菌SL1344株分泌性蛋白K1缺失株的构建及其生物学特性的初步研究
Construction and characterization of secreted effector K1 gene deleted mutant of Salmonella typhimurium SL1344 strain
摘要
Abstract
To develop safer and more effective alive attenuated Salmonella typhimurium vaccines,the recombinant suicide plasmid(PRF△sseK1) without 1 011 bp sseK1 gene was built by homologous recombination technology in this study.The sseK1 gene deleted mutant of Salmonella typhimurium SL1344 strain was screened using two-step method by recombinant suicide plasmid-mediated allelic exchange technology.The results of PCR,dual-enzyme digestion and sequencing showed that the SL1344△sseK1 strain was successfully constructed.It was found that the serotype of the mutant was 1,4,5,12 ∶i ∶ 1,2,identical to the parent SL1344,and the mutant was stable with the recombinant △sseK1 gene in vitro.In addention,we found that the sseK1 deletion mutant displayed identical growth profile and biochemical characteristics compared with the parent SL1344 strain.The mutant strain showed obvious changes in its virulence and oral challenge of bacteria in mice revealed that LD50of the mutant strain was 6.63×108 CFU,the toxicity being reduced about 0.048％.The immunoprotective effect assay showed that the serum IgG antibody could achieve the highest leverl on day 14 post-immunization,and the protection rate infected with wild strain of Salmonella typhimuriwwas 62.5％ on day 17 post-immunization.In conclusion,the SL1344△sseK1 mutant was constructed successfully,and genetic stability,and significantly reduced virulence,which laid a foundation for studies of the pathogenesis of sseK1 gene and further development of a safer and more effective candidate strain of attenuated Salmonella vaccines.关键词
鼠伤寒沙门菌SL1344/重组自杀性质粒/sseK1基因/生物学特性Key words
Salmonella typhimurium SL1344/recombinant suicide vector/sseK1 gene/biological characteristics分类
农业科技引用本文复制引用
杨亚东,张晓洁,张春杰,程相朝,丁轲,李银聚,郁川,廖成水,陈松彪,王二鑫..鼠伤寒沙门菌SL1344株分泌性蛋白K1缺失株的构建及其生物学特性的初步研究[J].中国兽医科学,2017,47(9):1087-1093,7.基金项目
河南省科技攻关项目(112102110019) （112102110019）
