IsrE,a Small Non-coding RNA of Invasion Gene Island(SPI-1)Involved in the Virulence of Salmonella enteritidis
Small non-coding RNAs (sRNA)of a kind of post-transcriptional regulators in bacteria have excited much interest lately and Salmonella has become a model organism for sRNA research.A small non-coding RNA.IsrE.was first identified in pathogenicity island (SPI-1)of Salmonella typhimurium.However,the regulation function of IsrE in virulence genes is still unknown.To investigate the regulation function of IsrE in virulence.we cloned the isrE gene in the reference strain S.enteritidis 50336,and then constructed the inframe deletion mutant 50336ΔisrE by the λ-Red-based recombination system.Novel target genes were screened by qRT-PCR.The result showed that the deletion of isrE significantly decreased the transcription of both outer membrane protein ompD (25-folds)and flagella subunitf/iC (8.6-folds)compared to those in wild type strain,while the motility of mutant 50336ΔisrE was decreased evidently.In addition,the transcription offimA,sefA,csgA,csgD and sthA in 50336ΔisrE were decreased about 3 to 5 folds.It indicated that IsrE could activate the transcription of ompD and fliC significantly and facilitates the expression of fimA,sefA,csgA,csgD and sthA in S.enteritidis.The mutant strain 50336ΔisrE exhibited an decreased ability to adhere to Caco-2 cells as well as the motility ability compared to the wild type strain.The pathogenicity of 50336ΔisrE was detected by infecting 1-day-old chickens by hypodermic injection.The LD50 of the wild type strain 50336 and the mutant 50336ΔisrE for 1-day-old chickens were 2.809×lO8 cfu and 4.084×lO8 cfu respectively.Our study shows that the deletion of isrE may attenuate the virulence of S.enteritidis in chickens by regulating expression of outer membrane protein OmpD,flagella FliC and fimbriae subunits.
Meng Xianchen Meng Xia Nie Jiajia Zhu Guoqiang
Ministry of Education Key Lab for Avian Preventive Medicine,College of Veterinary Medicine,Yangzhou University,Yangzhou 225009,China
国际会议
XVIth International Congress on Animal Hygiene(第十六届动物卫生国际会议(ISAH 2013))
南京
英文
489-491
2013-05-05（万方平台首次上网日期，不代表论文的发表时间）