Effects Of ε-PL On Growth And Biofilm Formation Of Acinetobacter Baumannii

Objective To understand the distribution,department distribution and drug resistance of Acinetobacter baumannii in a top three hospital in Gansu province;to study the inhibitory effect of ε-PL on the growth and biofilm formation of Acinetobacter baumannii,and to explore its effect on Acinetobacter baumannii The mechanism of action.Methods Acinetobacter baumannii isolated from January 2018 to December 2018 was collected,and the isolates were identified by MALDI-TOF MS.The K-B method was used for the drug sensitivity test,and the results were analyzed by WHONET5.6 software.Acinetobacter baumannii ATCC19606 and Acinetobacter baumannii clinical strain 48 strains were used as research objects,and the minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)were determined by reference to the micro-broth dilution method in the CLSI-M100 document;The growth curve of Acinetobacter baumannii ATCC19606 was observed by microplate reader.The effect of ε-PL on the biofilm formation of the strain was detected by 96-well plate crystal violet staining.The content of malondialdehyde(MDA)and reactive oxygen species(ROS)in the cells before and after drug treatment was determined.Results 245 strains of Acinetobacter baumannii were mainly respiratory tract(72.7%)and burn specimens(5.7%).The main distribution departments were intensive care unit(34.7%)and neurosurgery(15.5%).Isolated Acinetobacter baumannii mainly for piperacillin(81.2%),ampicillin/sulbactam(74.6%),piperacillin/tazobactam(79.6%),ceftazidime(79.6%),cefotaxime(81.9%),cefepime(78.8%),imipenem(78%),meropenem(78%),gentamicin(77.6%),tobramycin(73.7%),ring Propoxacin(77.5%),levofloxacin(75.9%),tetracycline(70%)were resistant,and no strains resistant to polymyxin B were found.Carbapenem-resistant Acinetobacter baumannii up to 78%.The MIC of ε-PL against ATCC19606 and clinical strains was 4.096mg/m L and MBC was 8.192 mg/m L.With the increase of ε-PL concentration,the effect of ε-PL on the growth and biofilm inhibition of Acinetobacter baumannii planktonic strains Obviously;the time-growth curve results showed that ε-PL could significantly inhibit the floating bacteria of ATCC19606 at 6h.ε-PL acts on Acinetobacter baumannii to induce an increase in malondialdehyde(MDA)and reactive oxygen species(ROS)levels in bacteria.Conclusion MALDI-TOF MS can quickly identify Acinetobacter baumannii.Acinetobacter baumannii is mainly isolated from respiratory specimens.The main distribution department is the intensive care unit and has a high resistance rate to antimicrobial agents.As a safe and effective natural preservative,ε-PL can effectively inhibit the growth of Acinetobacter baumannii bacteria and the formation of biofilm.The action of ε-PL on Acinetobacter baumannii can induce a large amount of active oxygen in the body.ROS)and malondialdehyde(MDA)suggest thatε-PL may exert bacteriostatic effects through oxidation.