Study On β-lactamase Inhibitors For Antibiotic Resistant Bacteria

Bacterial infection is very common in clinic.β-lactam antibiotics are the most commonly used antibacterial agents,which have the advantages of wide antibacterial spectrum,strong antibacterial activity and less side reactions.At present,due to the abuse of antibiotics and clinical irrational use of drugs,β-lactam antibiotic-resistant bacteria are frequently found.Further research shows that the main reason is that the drug-resistant bacteria produceβ-lactamase,which destroys the lactam ring and inactivates the antibiotics.The study of anti-drug resistant drugs targetingβ-lactamase is still a very effective means at this stage.Based on this,this study uses Chinese medicine and microbial materials as resources to screen outβ-lactamase inhibitors throung the aβ-lactamase inhibitor screening platform,which provided theoretical support for the in-depth study ofβ-lactamase inhibitors.The contents of this study were as follows:Optimization of screening methods for anti-resistant bacteriaβ-lactamase inhibitors.In the present study,the iodine reagent method and spectrophotometry were used to establish a convenient and rapid platform for screeningβ-lactamase inhibition.The optimized reaction conditions was as follows:maximum absorption wavelength was 571 nm,the substrate concentration of penicillin V potassium was0.02 mg/m L,β-lactamase enzyme concentration was 70 U/m L,tazobactam concentration was 0.03 mg/m L and temperature was 25°C.The optimizedβ-lactamase inhibitor screening platform was characterized by micro,rapid,efficient and stable.It was an effective means to find and discover potentially activeβ-lactamase inhibitors.Screening ofβ-lactamase inhibitors in microorganisms.332 strains were obtained and screened forβ-lactamase inhibitors by separating and purifying microorganisms from Angelica sinensis,Cordyceps and soil.The results showed that 162 strains had no inhibitory effect,and there were 34 strains with inhibition rate ofβ-lactamase above 70%.Some have false positives and are further verified by antibacterial activity.The results of antibacterial activity verification showed 34 strains had a certain inhibitory effect onβ-lactamase.Among them,CC-51,TRP-33 and TRP-71 had the best antibacterial effect,and the inhibition zone was respectively 21.5 mm,22.2mm,and 18.7 mm.Three high-activity strains were identified by morphological observation and molecular biological methods.TRP-33 and CC-51 strains were Aspergillus sp..TRP-71 strain was Penicillium oxalicum strain.These showed good development value and needed further research.Screening ofβ-lactamase inhibitors in 42 Chinese medicines.In the early stage,we collected,screened and finally determined 42 kinds of traditional Chinese medicine to be tested.Theβ-lactamase inhibitory activity of these herbs was measured,and it was found that there were 15 kinds of traditional Chinese medicines having an inhibition rate of 80.00%or more.Further verification by antibacterial activity showed that 15 kinds of Chinese medicinal materials have certain inhibitory effects onβ-lactamase.Among them,the inhibition zone of four kinds of Chinese herbal medicines were more than 18.00 mm,which is better than the positive drug Tazobactam,especially the inhibition zone of Sumu is 19.50mm.It lays the foundation for the research of traditional Chinese medicine prescriptions for anti-resistant bacteria.Tracking separation of compounds with high inhibitory activity ofβ-lactamase.The thin-layer chromatography（TLC）and column chromatography were used to trace theβ-lactamase inhibitory active components of the secondary metabolites of the TRP-33 active strains in the soil.Finally,the compounds H1 and H3 were identified as succinic acid and Fumitremorgin C by modern spectral techniques,while compounds H2,H4 and H5 did not identify results due to time.Among them,IC₅₀of the compound H4 is 0.689 mg/m L,showing relatively goodβ-lactamase inhibitory activity.In conclusion,our results showed that many the traditional Chinese medicines and their microorganisms have a certain inhibitory effect onβ-lactamase.Traditional Chinese medicine and its commensal microorganisms are abundant,which is a good resource for the development of newβ-lactamase inhibitors.