Correlation Between High Expression Of AdeABC Efflux Pump And Drug Resistance Of Carbapenem-resistant Acinetobacter Baumannii

Acinetobacter baumannii(AB)is an opportunistic pathogen that can easily cause serious hospital-acquired infections in people with low immunity.Carbapenem drugs are the most important therapeutic program in clinical practice at present,facing severe drug resistance situation,AdeABC discharge pump is an important mechanism of causing multi-drug resistance of AB.To determine the level distribution of carbapenem-resistant Acinetobacter baumannii(CRAB)in our hospital and the role of AdeABC efferent pump in the formation of carbapenem-resistant CRAB,we analyzed the clinical data of 63 CRAB and 22 CSAB collected from March 2019 to September 2020 in our hospital.The genotype,phenotype and adeB gene expression level of AdeABC efflox pump were studied,so as to provide the basis for defining the mechanism of CRAB resistance,guiding clinical rational drug use and hospital infection prevention and control.1.Clinical data analysis of CRAB and CSABMethods:Clinical data of CRAB and CSAB strains in the Second Hospital of Shanxi Medical University from March 2019 to September 2020 were collected and analyzed.Results:1.The ICU,neurosurgery and respiratory departments accounted for 85.7% of CRAB,which was the main distribution area.Respiratory specimens accounted for 84%and were the main source.All 63 CRAB,strains were multidrug resistant.2.ICU and respiratory department accounted for 45.4% of CSAB,which were the main distribution areas.Respiratory specimens accounted for 86% and were the main source.The 22 CSAB strains were sensitive to most commonly used antibiotics.2.Study on genotype,expression level and phenotype of AdeABC effluent pump Methods:adeABC gene and regulatory genes were amplified by PCR.MIC was detected by microbroth dilution method.The phenotype of the effluent pump was detected by CCCP.The expression level of adeB was detected by RT-PCR.Results:1.The positive rate of adeB in CRAB group was 90.5%(57/63),and the positive rates of adeA,ade C,adeR and adeS were 95.2%(60/63).The positive rates of adeB in CSAB group was 9.1%(2/22),the positive rates of ade C was 95.5%(21/22),and the positive rates of adeA,adeR and adeS were 59.1%(13/22).2.The phenotypic positive rates for meropenem and imipenem were 57%(36/63)and 60%(38/63)of 63 Crab strains.3.The expression level of adeB in 2 CRAB strains was 6.1 times and 0.04 times that of CSAB strains.Conclusion:1.AB is mainly distributed in ICU in our hospital,and respiratory tract is the main source of specimens.ICU is still the main department for hospital infection prevention and control.2.In our hospital,CRAB was multidrug resistant,pan-drug resistant,and had a high level of resistance to carbapenems.Therefore,the management of carbapenems antibiotics should be strengthened to curb drug resistance.3.The positive rates of adeA,adeB,adeR and adeS genes were significantly different between the CRAB group and the CSAB group(P < 0.05),suggesting that AdeABC and regulatory genes were related to CRAB resistance.4.The positive rates of efflox pump phenotypes in CRAB group were greater than50% for meropenem and imipenem,suggesting that efflox pump is one of the main causes of AB’s high level of carbapenem resistance.5.Compared with CSAB,Ade B gene expression level was increased in some strains with positive efflox pump phenotype,which was consistent with the efflox pump phenotype.Based on the above phenotype and genotype results,it is suggested that AdeABC efflox pump plays an important role in carbapenems resistance of CRAB in our hospital.