Effects of pagP gene of avian pathogenic Escherichia coli on its antimicrobial peptide resistance and pathogenicity

Abstract:

[Objective] Avian pathogenic Escherichia coli (APEC) leads to significant economic losses in poultry production, and affects public health. pagP gene plays key roles in pathogenicity and antimicrobial peptide resistance of bacteria. However, the function of pagP in APEC is still unknown. To determine the antibacterial peptide resistance and pathogenicity of pagP mutant strain, APEC pagP mutant strain was constructed. [Methods] We constructed APEC-pagP mutant strain with red recombination system, and the corresponding complementary strain was also constructed. We detected the effects of PagP in cell adhesion and invasion, biofilm-forming ability, outer membrane permeability, antibacterial peptide sensitivity and pathogenicity. [Results] pagP mutant strain and complementary strain were successfully constructed. The antimicrobial peptide resistance tests showed that pagP mutant strain was more sensitive to Polymyxin B and AVBD2 (P<0.01). The pathogenic test showed a significantly reduction of toxicity in pagP mutant strain (P<0.01). [Conclusion] pagP gene in APEC played important roles in resistance to AVBD2 and pathogenicity in APEC.