The Study Of Drug Resistance Gene And Epidemiology Of Carbapenem-resistant Escherichia Coli

Objective To understand the drug-resistant genotypes and epidemic trends of carbapenem resistant Escherichia coli in xinhua hospital affiliated to Shanghai Jiao Tong University for providing clinical treatment advices when use antibiotics reasonably and theory evidence in hospital infection of Escherichia coli.Methods 1.Collected non-repetitive carbapenem-resistant Escherichia coli strains isolated from clinical inpatients specimens in xinhua hospital affiliated to Shanghai Jiao Tong University School of Medicine from March 2009 to December2017,with strain detection and drug sensitivity test followed.2.Rapidly screened the carbapenemase production of Escherichia coli isolates by mCIM.3.Classical PCR combined with DNA sequencing was performed to detect the common carbapenemase genes,such as bla _KPC,bla_VIM,bla _IMP,bla _GES,bla_NDMDM and bla _OXA.4.Multilocus Sequence Typing（MLST）was used to identify the genotypes of carbapenem-resistant Escherichia coli collected above.5.Analyze the clinical data of inpatients along with experimental results to characterize the epidemiological features of carbapenem-resistant Escherichia coli.Results 1.A total of 84 carbapenem-resistant Escherichia coli isolates were collected in this study.2.mCIM detection showed that 71 strains of them were positive.3.PCR results of antibiotic resistant genes revealed that there are 65 strains carrying bla_NDM,and most of them are bla_NDM-5DM-5 and bla_NDM-1.Of all the strains which carried bla_NDM,two of them were both bla_NDM-1DM-1 and bla_MCR-1CR-1 positive.Besides,6 strains carried only bla_kpc-2.4.MLST typing gave the result that there are 29 ST types in total with 7new types found.ST406 and ST2 are the major ST types,and most of them carried blaNDM-5.Conclusion 1.Carbapenem-resistant Escherichia coli is highly resistant to most antibiotics,and carbapenemase producing was the main resistance mechanism.NDM-5 and NDM-1 were the major enzymes.2.The pediatric intensive care unit was the most severe department in hospital.The main carbapenem-resistant Escherichia coli types in pediatric patients are ST406,ST2 and ST692,while in elderly patients is ST477.3.The high detection rate of carbapenem-resistant Escherichia coli in pediatric patients and high diversity of strains’antibiotic resistant genes and ST features found here suggested that strict antibiotic drugs use and measures for disinfection and isolation were needed to prevent the spread of Carbapenem-resistant Escherichia coli.