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构建禽致病性大肠杆菌(APEC)Ⅵ型分泌系统2(T6SS2)clpB基因缺失株、互补株,研究clpB基因对APEC生物学特性及致病性的影响。采用Red同源重组系统构建APEC clpB基因缺失株,并利用低拷贝质粒pSTV28构建互补株。比较分析野生株、缺失株与互补株的生长曲线、运动性、生物被膜形成能力、黏附侵袭能力、胞内存活能力、动物致病力等生物学特性的差异。结果显示,clpB基因缺失不影响APEC的生长速度和黏附侵袭能力。然而,缺失ClpB导致APEC运动能力降低、生物被膜形成能力升高、HD-11胞内存活能力降低、体内存活能力及致病力降低。本研究分析了T6SS2核心组分Clp B的作用,为阐述APEC T6SS2致病作用提供了参考。
To construct the clpB gene deletion mutant and complementary strain of avian pathogenic Escherichia coli (APEC) type Ⅵ secretion system 2 (T6SS2) 2 and study the influence of clpB gene on the biological characteristics and pathogenicity of APEC. The APEC clpB gene deletion strain was constructed by using Red homologous recombination system and a complementary strain was constructed by using low copy plasmid pSTV28. The biological characteristics of wild strain, deletion strain and complementary strain were compared, such as growth curve, motility, biofilm formation ability, adhesion and invasion ability, intracellular viability and animal pathogenicity. The results showed that clpB gene deletion did not affect the growth rate of APEC and the ability of adhesion and invasion. However, the absence of ClpB led to reduced APEC motor ability, increased biofilm formation, decreased intracellular viability of HD-11, and decreased in vivo viability and virulence. This study analyzed the role of Clp B, the core component of T6SS2, to provide a reference for elucidating the pathogenic role of APEC T6SS2.