猪源产肠毒素大肠杆菌eltA、flhD、fimA、faeG基因启动子的预测、克隆和鉴定  

Prediction,clone and identification of eltA,flhD,fimA and faeG gene promoter in porcine enterotoxigenic E.coli

作　　者：胡会杰[1,2] 周明旭[1,2] 许绵[1,2] 张琪[1,2] 羊扬[1,2] 朱国强[1,2] 

机构地区：[1]扬州大学兽医学院,江苏扬州225009 [2]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》2015年第10期1640-1645,共6页Chinese Journal of Veterinary Science

基　　金：江苏高校优势学科建设工程资助项目;国家自然科学基金资助项目(30571374;30771603;31072136;31270171)

摘　　要：猪源产肠毒素大肠杆菌(ETEC)是引起仔猪腹泻的主要病原菌之一,其致病机制与染色体上特定的毒力岛以及毒力质粒上的某些毒力基因相关。基于对ETEC毒力因子的前期研究,本研究初步预测并鉴定了eltA基因(编码LT毒素A亚单位)、flhD基因(编码鞭毛系统一级调控子)、fimA基因(编码I型菌毛主要结构亚基)和faeG基因(编码K88菌毛主要结构亚基)的启动子位置。通过构建含eltA、flhD、fimA、faeG基因启动子的LacZ报告质粒,利用β-半乳糖苷酶试验检测其活性,为进一步定位启动子、确定启动子序列,探索猪源ETEC毒力调控关系,了解细菌感染过程中各毒力因子的表达规律奠定试验基础。Porcine enterotoxigenic E.coli（ETEC）is one of the main cause of porcine post-weaning diarrhea,which pathogenesis is correlated with specific virulence islands on chromosome and certain virulence genes on plasmid.Based on the previous studies for ETEC virulence factors,we preliminarily predicted and identified the position of the gene promoters,which including the eltA gene（encoding the LT toxin A subunit）,flhD gene（encoding the flagella major regulator）,fimA gene（encoding the major structural subunit of type I fimbriae）and faeG gene（encoding the major structural subunit of K88 fimbriae subunit）.Sequentiallywe constructed the lacZ reporter plasmids which respectively contain eltA,flhD,fimA,faeG gene promoter,and detected the activity of each gene promoter by usingβ-galactosidase enzyme assay.This study helped define the promoter sequence,contributed to understand virulence regulatory relationships in porcine ETEC,and laid the foundation for investigating the virulence factors expression pattern during bacterial infection.

关 键 词：产肠毒素大肠杆菌 K88 启动子 LacZ报告质粒 

分 类 号：S852.612[农业科学—基础兽医学]