Study On Clinical Drug Resistance Of Carbapenemase-producing Enterobacteriaceae And Rapid Detection Of KPC Enzyme

Objective To analyze the resistance of Carbapenem-resistant Enterobacteriaceae(CRE)to common antibacterials and the production of enzymes in inpatients from the General Hospital of Tianjin Medical University;to investigate the resistance of key departments and bloodstream infections Clinical characteristics of Carbapenem-resistant Klebsiella pneumoniae(CRKP)hospitalized patients,infection-related risk factors,and prognosis of patients under different clinical medication regimens.For KPCase-producing CRKP,based on MALDI-TOF A rapid screening method is established for the characteristic peaks of the protein map of MS to clarify the main drug resistance mechanism of CRE in our hospital,guide clinicians to formulate a reasonable treatment plan and achieve rapid screening for enzyme-producing strains,and effectively control CRE in the hospital.propagation.Methods A total of 251 CRE isolates from clinically infected patients were collected from the General Hospital of Tianjin Medical University from September 2017 to December 2019.Repetitive strains were eliminated.Bacterial identification was performed by MALDI-TOF MS mass spectrometer.Diffusion method(Kirby-Bauer,KB),micro broth dilution method for in vitro drug sensitivity tests on common drugs,m CIM combined with e CIM method for CRE enzyme phenotype detection,PCR method for enzyme gene production,Analyze its specimen types,department sources,drug sensitivity results,and enzyme production;use retrospective 1: 1 case-case-control studies to analyze risk factors for infections in key departments and bloodstream infections,and CRKP for different treatment options Compare the outcomes of patients with bloodstream infection,and evaluate the accuracy of q Pitt score and q SOFA score for predicting the death of CRKP bloodstream infections.For KPCase-producing CRKP strains,look for KPC through the MALDI-TOF MS mass spectrometer RUO system Characteristic peaks of enzyme proteins,a rapid screening method for KPC enzymes was established.Results(1)251 CRE specimens were mainly carbapenem-resistant Klebsiella pneumoniae(CRKP)235(93.6%)and carbapenem-resistant Escherichia coli(CR-ECO)12 strains(4.8 %);30 wards from our hospital were distributed widely,and 66.5% were isolated from ICU wards.The experimental strains are resistant to most antibacterials in vitro,and most of the strains remain sensitive to tigecycline.No polymyxin or ceftazidime-avibactam-resistant strains have appeared in our hospital,and no Clam strain of blamcr-1.Carbapenemase is the main resistance mechanism of CRE in our hospital,and most of them are KPC enzymes(84.5%).(2)Because of its invasive and interventional procedures,NICU is mostly complicated and critically ill,and it is prone to nosocomial infection.Multivariate binary logistic regression analysis showed abnormal liver function(OR = 20.6,P <0.001),lumbar puncture(OR = 6.3,P <0.05),bronchoscopy(OR = 9.8,P <0.05),carbapenem The history of exposure to antibacterials(OR = 13.2,P <0.05)and patient age(OR = 1.0,P <0.05)were independent risk factors for CRKP infection in patients with NICU.(3)The mortality rate of 45 strains of CRKP patients with bloodstream infection is 57.8%.Whether antifungal drugs have been taken is an independent risk factor for CRKP bloodstream infection that is different from CSKP bloodstream infection.For the treatment of patients with CRKP bloodstream infections,the combined regimen has a lower mortality rate than the single regimen,and the regimen treated with tigecycline has a higher mortality rate than the regimen not treated with tigecycline.Both q Pitt score and q SOFA score can be used to predict the prognosis of patients with CRKP bloodstream infection.The area under the ROC curve of q SOFA AUC = 0.832(95% CI: 0.716-0.949 P <0.001)is better than q Pitt score AUC = 0.704(95% CI : 0.544-0.864 P <0.05).Among them,the cutoff value for predicting the prognosis of patients with CRKP bloodstream infection was 2,the sensitivity was 72.2%,the specificity was 74.1%,the positive predictive value was 65.0%,and the negative predictive value was 80.0%.The cutoff value for predicting the prognosis of patients with CRKP bloodstream infection was a q Pitt score of 2,sensitivity,72.2%,specificity of 55.6%,positive predictive value of 52.0%,and negative predictive value of 75.0%.(4)Under the detection of RUO system based on MALDI-TOF MS mass spectrometer,KPC-producing CRKP has characteristic peaks at 4518 ± 8m / z,which is helpful for early clinical screening of KPC-producing strains and preventing their spread in the hospital..Conclusion The prevalent CRE in our hospital is CRKP that produces KPC enzymes.It is resistant to most antibacterial drugs and has good sensitivity to tigecycline.There is no resistant strain to polymyxin or ceftazidime-avibactam.For the NICU of the key department of CRKP separation,elderly patients with abnormal liver function,lumbar puncture,bronchoscopy,and a history of carbapenem exposure should focus on preventing nosocomial infections in CRKP.Taking antifungal drugs is a factor that distinguishes CRKP bloodstream infections from CSKP bloodstream infections.The combined treatment of CRKP bloodstream infections is better than monotherapy,and it is better to use without tigecycline,and q Pitt score and q SOFA score It can be used to predict the prognosis of patients with CRKP bloodstream infection.The laboratory can realize rapid screening of KPC enzymes through MALDI-TOF MS,provide timely and accurate reference for clinical medication,and prevent and block the spread of CRE in our hospital.