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

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．