Study On Drug Resistance Mechanism Of Bacterial Membrane Vesicles Mesosome Mediated H₂O₂ Efflux

In recent years,the problem of bacterial resistance has become increasingly serious,which has brought major challenges to anti-infective treatment.The emergence of a variety of super bacteria makes the in-depth study of drug resistance mechanisms urgent.In this experiment,wild-type Escherichia coli(E.coli)MG1655and its gene mutant strains were used as research objects.Screening genes related to the resistance mechanism of mesosome mediated hydrogen peroxide efflux,and analyzing the role of these gene mutants in the resistance mechanism of mesosome mediated resistance after antibiotic damage.The main research contents and results are as follows:1)The properties of the isolated mesosome were analyzed by SDSpolyacrylamide gel electrophoresis,nanoparticle tracking analysis,biological transmission electron microscope and gas chromatography-tandem mass spectrometry.The data showed that the relative molecular weight was about 13 KDa,the particle size was about 46 nm,and contained 96 protein components by the mesosome.2)According to the protein composition and high-throughput transcriptome sequencing of the mesosome,screened were four genes related to the resistance mechanism of mesosome mediated,including aquaporin(Aqp Z),glycerol-aquaporin(Glp F),Glycerol phosphodiester phosphodiesterase(Glp Q)and outer membrane protein(Omp A),and successfully constructed the corresponding mutant strain.3)The drug resistance test results of the mutant strain showed that the four genes screened had a certain effect on the durg resistance of E.coli,and the resistance of the mutant strain to gentamicin showed the sensitivity of the gene deletion strain and the overexpression strain,and compared with the results of other antibiotics(norfloxacin,chloramphenicol,ceftiofur sodium),the results show a certain pattern and trend,and that 5 μg/ml gentamicin is an appropriate antibiotic and concentration for injuring bacteria and inducing bacteria to produce mesosome.4)Using the Image-Pro Plus image software to calculate the accumulation of extracellular hydrogen peroxide of these mutant strain,it was shown that the accumulation of extracellular hydrogen peroxide of the overexpressing strains of aqp Z and glp F genes was significantly higher than that of the control group(P values were0.008 and 0.046,respectively).The comprehensive drug resistance test results and extracellular hydrogen peroxide level data strongly suggest that Aqp Z and Glp F channel proteins play an important role in the durg resistance mechanism in the mesosome mediated efflux of hydrogen peroxide.In this project,the study on the mechanism of mesosome-genes participating in drug resistance provides a theoretical basis for the further study of mesosome and a strategy for the development of new antibacterial drugs.