Study On The Effect Of Taurine Chloramine On The Resistance Of Escherichia Coli To Quinolone Drugs

Escherichia coli is one of the most common clinical strains in animal husbandry.Pathogenic E.coli can cause local or systemic infections in humans and livestock and poultry.E.coli can cause diarrhea and inflammation in livestock and poultry,especially young animals(poultry).Even septic diseases and so on.Clinically,quinolone drugs are one of the commonly used drugs in clinical practice.Abuse and wrong administration methods make E.coli severely resistant to quinolone drugs.In recent years,the resistance rate of E.coli quinolones in Beijing,Xinjiang,Guangxi and other places has all been above 60%.Taurine Chloramine(Tau Cl)is a halogenated product produced by taurine in the body's inflammatory environment.It has good antibacterial activity and can effectively kill a variety of Gram-positive and Gram-negative bacteria,Fungi,inactivates viruses,and can kill a variety of parasites.It has also been proven to neutralize the Shiga toxins of enterohemorrhagic E.coli by oxidizing the mercaptans and aromatic amino acids of bacterial proteins,and inhibit the patina Bacillus biofilm formation.This study intends to detect the effects of taurine chloramine on quinolones before and after the effect of taurine chloramine.Antibiotic resistance,quinolone resistance efflux gene and outer membrane porin gene m RNA expression changes,analysis of taurine chloramine effect and mechanism of reducing E.coli resistance to quinolone drugs,lay a theoretical foundation for the development and application of taurine chloramine as an antibacterial drug.In this experiment,the double micro broth dilution method was used to determine the MIC of ciprofloxacin hydrochloride against E.coli,and a multi-step method was used to induce resistance to E.coli ATCC5922;Determination of ciprofloxacin hydrochloride combined with taurine chloramine by micro checkerboard dilution method to determine the Fractional inhibitory concentration(FIC)of two drugs combined antibacterial;Use 16 m M/L,10 m M/L,8m M/L,4m M/L taurine chloramine to act on 32 MIC and 64 MIC drug-resistant bacteria continuously for 18 h to determine the optimal concentration of Tau Cl,and use this concentration to act on three strains continuously.For drug-resistant strains,the micro broth dilution method and KB drug-sensitive disk method were used to determine the MIC and inhibition zone diameters of the three drug-resistant strains before and after the action of Tau Cl;Fluorescence quantitative PCR technology was used to detect the expression levels of E.coli efflux genes acr A,acr B,tol C and their regulatory genes mar A,rob genes and virulence genes Omp C and Omp F genes before and after the action of taurine chloramine.The experimental results show:(1)Ciprofloxacin hydrochloride induces ATCC25922 standard strains,and obtains three resistant strains of different degrees,The drug resistance is 32 times,64 times,128 times that of ATCC25922 MIC respectively;(2)The MIC value of taurine chloramine(Tau Cl)is 16 m M/L(the original concentration is 550 m M/L),this indicates that taurine chloride amine(Tau Cl)has good antibacterial activity;(3)the FIC value of the combined application of ciprofloxacin hydrochloride and Tau Cl is 0.5< FIC<1,the two have an synergistic effect;(4)At a subinhibitory concentration of 10 m M/L Tau Cl can inhibit the growth of E.coli while maintaining the activity of E.coli.Compared with the strains that are not affected by taurine chloramine,the logarithmic growth phase is slow,it shows that the growth of E.coli is inhibited by taurine chloramines,the stable period is significantly reduced,and E.coli quickly enters the decay period at about 18h;(5)Treating three resistant strains with 10 m M/L Tau Cl for 18 hours and continuously acting for several generations can reduce the MICs of resistant bacteria to varying degrees;(6)Compared with the strain before the drug action,taurine chloramine(Tau Cl)can significantly reduce the efflux pump genes acr A,acr B,tol C and the efflux pump regulatory genes mar A,rob genes of E.coli resistant bacteria(P<0.01).As well as the expression levels of the virulence gene Omp C and Omp F(P<0.01),the difference is extremely significant,indicating that taurine chloramine effectively inhibits the E.coli efflux pump,destroys the integrity of the E.coli cell membrane,and reduces the virulence of E.coli.The study proved that Taucl may reduce the drug resistance of E.coli by inhibiting the expression of efflux genes acr A,acr B,tol C and regulatory genes mar A,rob gene m RNA,and Simultaneously,reducing the expression of the outer membrane porin Omp C and Omp F gene m RNA significantly lower the virulence of E.coli,to achieve the purpose of reducing the resistance of Escherichia coli to quinolone drugs.This study will lay a theoretical foundation for the in-depth study of the mechanism of Tau Cl in reducing bacterial resistance and its use as a new type of drug.