空泡形成毒素影响禽致病性大肠杆菌的生物学特性及致病性

Vacuolating autotransporter toxin affects biological characteristics and pathogenicity of avian pathogenic Escherichia coli

摘要:

摘要:【目的】构建禽致病性大肠杆菌(Avian pathogenic Escherichia coli，APEC)菌株APEC-O1空泡形成毒素(Vacuolating autotransporter toxin，Vat)基因缺失株，研究该基因对APEC-O1生物学特性及致病性的影响。【方法】采用Red同源重组的方法构建vat 缺失株，并利用低拷贝质粒pSTV28构建互补株，然后比较野生株、vat缺失株与互补株在生长特性、运动性、凝集沉淀能力、生物被膜、致病性等生物学特性的差异。【结果】vat基因缺失不影响APEC-O1的生长速度及抗环境压力能力，但缺失vat导致APEC-O1运动能力增强，而使生物被膜形成能力、凝集沉降能力、致病力、体内存活能力均显著性减弱。【结论】Vat缺失影响APEC-O1运动能力、凝集沉淀能力、生物被膜形成能力及致病力，为全面了解Vat 的致病作用提供参考。

Abstract:

Abstract:［Objective］ To determined the role of vacuolating autotransporter toxin (vat) gene in avian pathogenic Escherichia coli (APEC)，we detected the biological characteristics and pathogenicity of vat gene mutant strain of APECO1．［Methods］We constructed the vat mutant and complementary strain of APEC-O1 by the Red recombination system and plasmid pSTV28． Then we compared the growth curve，motility，agglutination，biofilm formation and pathogenicity of mutant strain，wild-type strain and complementary strain．［Results］ The vat mutant did not affect the growth and resistance to environment stress of APEC．However，inactivation of APEC-O1 vat gene resulted in enhanced motility， diminished agglutination，decreased biofilm formation and attenuated virulence in ducks．［Conclusion］ These data indicated that Vat affect the motility，agglutination，biofilm formation and virulence of APEC-O1，which help us to understand the role of the Vat in the APEC pathogenicity．