Analysis Of Carbapenem Resistance Of Klebsiella Pneumoniae And Escherichia Coli In A Hospital In Jilin Province

Objectives:By analyzing the epidemic status of carbapenem resistant Klebsiella pneumoniae and Escherichia coli in a hospital in Jilin Province,understand and master the drug resistance rate of carbapenem resistant Klebsiella pneumoniae and Escherichia coli,and carry out the carrying and mutation characteristics of a variety of carbapenem resistant Enterobacteriaceae（CRE）related drug resistance genes,By analyzing the mutation characteristics of CRE dominant genes in a hospital in our province,a rapid screening and detection technology for CRE is established,which provides important research content for formulating prevention and control strategies for the development of CRE.It is of great significance to improve the clinical cure rate of CRE infection in Jilin Province and finally achieve the ultimate goal of who"curbing global drug resistance".Methods:Based on the pathogen monitoring project of the Chinese Pathogen Identification Net,the daily monitoring strains and CRE strains were collected and sent to Jilin provincial CDC.Daily monitoring strains:a total of 353 strains.From September 2019 to September2021,15 strains of Klebsiella pneumoniae or Escherichia coli were collected by the laboratory department of a hospital in Jilin province every month.After biochemical review,they were identified as Klebsiella pneumoniae and or Escherichia coli.After excluding the unqualified strains,228 strains of Klebsiella pneumoniae and 125 strains of Escherichia coli were collected.CRE strain:67 strains in total.Among them,61 strains of Klebsiella pneumoniae and Escherichia coli resistant to carbapenems were collected from the laboratory department of a hospital in Jilin Province from June 2017 to June 2019,and 58 strains were resistant after review;From September 2019 to September 2021,9 drug-resistant strains were detected in the daily monitoring strains.At the same time,the source and case related information of strains were collected.Strains were tested for drug sensitivity by micro broth dilution method,including ertapenem（ETP）,imipenem（IMP）and meropenem（MEM）;Six carbapenem resistant genes(bla _KPC、bla _NDM、bla _OXA-48、bla _GES、bla _VIM、bla _IMP)of CRE strain were amplified,and the PCR products were sequenced.The counting data were expressed by rate or composition ratio.The difference of the detection rate of drug-resistant genes among different drug-resistant strains was compared byx~2test.The sequence splicing of gene fragments was carried out by seqman software in DNAStar software,and the comparison of differential genes was carried out by MEGA5software.P<0.05,the difference was considered statistically significant.Result:1.Overall drug resistance phenotype test results:through drug sensitivity test,among353 strains obtained from daily monitoring,there were 228 strains of Klebsiella pneumoniae and 6 strains of drug-resistant strains,with a drug resistance rate of 2.63%;There were 125strains of Escherichia coli and 3 drug-resistant strains,with a drug resistance rate of 2.40%.Among the 61 strains specially collected by Cre,50 strains of carbapenem resistant Klebsiella pneumoniae,8 strains of carbapenem resistant Escherichia coli and 3 strains of intermediary Klebsiella pneumoniae were rechecked and identified.2.The drug resistance of 228 strains of Klebsiella pneumoniae to three carbapenems was monitored daily:the single drug resistance rates of MEM,ETP and IPM were 0.00%,0.44%and 0.44%respectively;The multidrug resistance rate was 1.75%;The resistance rates to MEM,ETP and IPM were 1.32%,1.75%and 2.19%,respectively.The single drug resistance rate of 125 strains of Escherichia coli to MEM,ETP and IPM was 0.00%;The multidrug resistance rate was 2.40%;The resistance rates to MEM,ETP and IPM were2.40%,2.40%and 2.40%respectively.3.Resistance of CRE strains to three carbapenem drugs:among 56 carbapenem resistant Klebsiella pneumoniae strains,the proportion of single drug resistant strains was 3.57%（2/56）;The proportion of multidrug-resistant strains was 96.43%（54/56）.Among the 11carbapenem resistant Escherichia coli strains,the proportion of single drug resistant strains was 0.00%（0/11）;The proportion of multidrug-resistant strains was 100.00%（11/11）.4.Gene mutation of CRE strain:（1）Among 56 strains of carbapenem resistant Klebsiella pneumoniae,31 strains carried bla _KPCgene,10 strains carried bla _NDMgene,and 4strains carried bla _KPC+bla _NDMgene at the same time.Bla _OXA-48,bla _IMP,bla _VIMand bla _GESgenes were not detected.In typing,bla _KPCwas bla _KPC-2,and T→C mutation was detected at position 814 of bla _KPCgene.Bla _NDMdetected 2 strains of bla _NDM-1;A→C mutation was detected at position 460 of bla _NDM-4gene in 6 strains;For two ndm-5 strains,G→T mutation was detected at position 262 and A→C mutation was detected at position 460.（2）bla _NDMgene was detected in 10 of 11 carbapenem resistant Escherichia coli strains.Bla _KPC,bla _OXA-48,bla _IMP,bla _VIMand bla _GESgenes were not detected.In bla _NDMtyping,5 strains of bla _NDM-1were detected;Two bla _NDM-4strains had A→C mutation at position 460 and M→L mutation at position 154;Two bla _NDM-5strains had G→T mutation at position 262 and A→C mutation at position 460;One bla _NDM-7strain had G→A mutation at position 388 and A→C mutation at position 460.5.Difference in detection rate:there was significant difference in the detection rate of bla _NDM-1between carbapenem resistant Klebsiella pneumoniae and carbapenem resistant Escherichia coli（P=0.001）.Conclusion:1.In this study,the resistance rate of Klebsiella pneumoniae to carbapenems（2.63%）was lower than the national average resistance rate（10.9%）,and the resistance rate of Escherichia coli to carbapenems（2.40%）was similar to the national average resistance rate（1.6%）.2.Carbapenem resistant Klebsiella pneumoniae and carbapenem resistant Escherichia coli have cross resistance to MEM,ETP and IPM.3.Carbapenem resistant Klebsiella pneumoniae mainly carries drug resistance genes bla _KPCand blandm,among which bla _KPCis the most common.bla _KPCis mainly classified as bla _KPC-2,and bla _NDMis mainly classified as bla _NDM-1,bla _NDM-4and bla _NDM-5.Carbapenem resistant Klebsiella pneumoniae carried bla _KPCand bla _NDMat the same time.4.Carbapenem resistant Escherichia coli mainly carries the drug resistance gene bla _NDM,the carrying rate is 90.91%,and the most common typing is bla _NDM-1.There was significant difference in the detection rate of bla _NDM-1between carbapenem resistant Klebsiella pneumoniae and carbapenem resistant Escherichia coli.5.The mutation sites of bla _KPCand bla _NDMgenes in this study are consistent with other studies.