Analysis Of Susceptibility Factors And Drug Resistance Phenotype And Gene Of Acinetobacter Baumannii

Objective:To study the risk factors related to acinetobacter baumannii infection in hospital and construct a prediction model.The characteristics and distribution of acinetobacter baumannii infection were analyzed.The main drug resistance genes causing multiple drug resistance were detected and the mechanism of drug resistance was analyzed.Prediction of drug resistance trends of Acinetobacter baumannii in the next five years.To provide basis for rational selection of antibacterial drugs in clinic.Methods:The risk factors of acinetobacter baumannii infection in hospital were explored by Logistic regression analysis,and the risk prediction model was established.3580 strains of Acinetobacter baumannii isolated from a microbiology laboratory of a grade A hospital in Shanxi Province from January 2019 to August 2021 were analyzed retrospectively,and the infection distribution characteristics were analyzed.BLAoxa-23,BLAOXA-51,bla KPC,BLAOXA-24,bla NDM,OXA-58,bla VIM and ade B,car O,aba I,bfm S and qac E were detected by PCR.To analyze the epidemic genotype of Acinetobacter baumannii and its mechanism of multiple drug resistance.The drug resistance trend and drug resistance rate of main clinical drugs(carbapenems, cefoperazone and sulbactam,minocycline and tigecycline)against Acinetobacter baumannii in the next 5 years were analyzed and predicted by SVM regression model.Results:Multivariate analysis showed that surgical history(P=0.03,OR= 2.912),heart disease(P=0.008,OR=3.194),indwelling stomach(P=0,OR= 5.584),deep vein catheterization(P=0.008,OR=2.709),Glucocorticoid shock(P<0.01,OR=0.022)constituted an independent risk factor for nosocomial infection of ACinetobacter baumannii.The risk factor prediction model for Acinetobacter baumannii was established F(X)=1.069× surgical history +1.161× heart disease +1.72× indwelling gastric tube +0.997× deep vein catheterization + glucocorticoid× 0.997-3.814,and the area under the curve was >0.6,which was within a reasonable range.3580 strains of Acinetobacter baumannii were detected,mainly from sputum,alveolar lavage fluid and blood.The proportion was 76% for men and 24% for women.At the same time,the older the age,the higher the positive rate of pathogenic bacteria,and the positive rate of the elderly >65 years old is the highest.ICU and neurosurgery had the highest detection rate.PCR detection of drug-resistance related genes showed that β lactam class A enzyme KPC was not detected in 60 strains AB,and class B enzyme bla VIM(13%,8/60)bla NDM(96%,58/60),Class D enzymes BLAOXA-51(100%,60/60),Bla OXA-23(98%,59/60),bla OXA-58(6%,4/60)bla OXA-24(5%,3/60).Mdr-ab resistance gene results car O(98%,59/60),ade B(100%,60/60),qac E(55%,33/60),virulence factors aba I(5%,5/60),bfm S(90%,54/60).By support vector machine(SVM)regression model analysis the main trend of antibiotic resistance to change,the results show that in the next five years(2020-2025)carbon penicillium alkene antibiotic resistant rate above 90%,Cefoperazone / sulbactam will reach more than 80% in the next two years,and the resistance rate of minocycline and tegacyclin will increase steadily in the future。Conclusion:Clinical care should be strengthened after surgery,monitoring of patients with heart disease,and the use of glucocorticoids should be reduced to reduce AB infection.The drug resistance rate of imipenem and meropenem in this region was higher than the national average.The drug resistance to carbapenase in this region is caused by ox A-51+OXA-23+OXA-24+OXA-58+bla VIM+bla NDM gene.The high detection rate of car O and ade B genotypes in this region indicated that the change of bacterial outer membrane protein and overexpression of effusion pump were the main mechanism of forming multiple drug resistance,even pan-drug resistance.Disinfectants qac E,virulence factors aba I and bfm S must be paid attention to in clinical diagnosis and treatment.