PpkA,A Ser/Thr Protein Kinase Regulates Virulence And Antibiotic Resistance In Pseudomonas Aeruginosa

Pseudomonas aeruginosa is a gram-negative,opportunistic pathogen that causes clinical infections,and is also a common antimicrobial resistance bacteria.Ser/Thr phosphorylation impact virulence and antimicrobial resistance in bacteria.This study intends to reveal the regulation of PpkA,a Ser/Thr kinase to virulence and antimicrobial resistance in P.aeruginosa.We verify the correlation of PpkA and virulence in P.aeruginosa through the comparison of PAO1 and ?ppkA in various aspects: the ability of invasion to Hela cells,the virulence in the plant model of infection,the secretion of Pyocyanin,the resistance to oxidative and osmotic stress,the formation of biofilm.According to the results,we suggest that PpkA can enhance the virulence of P.aeruginosa.The experiments to verified the correlation of PpkA and antimicrobial resistance in P.aeruginosa,PAO1 were subcultured in broth containning 1/2 concentration Gentamicine and induced antimicrobial resistance strains successfully.Subsquently,compaired with PAO1,the antimicrobial resistance strains exhibited the Ser/Thr protein phosphorylation upregulated,as well as Stk1 and PA1782 expression.We found that minimal inhibition concentrations(MIC)of PAO1 and ?ppkA were the same to many kinds of antibiotics.But compaired with ?ppkA,Ser/Thr phosphorylation expression of membrane protein in PAO1 is upregulated,and the Stk1 and PA1782 expression is downregulated.When ?ppkA subcultured in broth containning sub-inhibitory concentration of Ceftazidime,Gentamicin,Imipenem,the formation of biofilm in ?ppkA had increased.Results reveal the impact of PpkA to virulence in P.aeruginosa and antimicrobial resistance in P.aeruginosa.Research provide theoretical basis for the in-depth study of the Ser/Thr kinase which could regulate virulence,antimicrobial resistance in P.aeruginosa,and contribute to the treatment of P.aeruginosa infection.