Abstract:ObjectiveTo study the resistance mechanisms of carbapenemresistant Enterobacteriaceae(CRE) to carbapenems and cephalosporins, and provide molecular evidence for the treatment of CRE infection and control of healthcareassociated infection.MethodsClinically isolated bacteria in 2014-2015 were identified and performed antimicrobial susceptibility testing by MicroScan Walkaway40 plus system, encoding genes of carbapenems(blaNDM1 and blaKPC2) and encoding genes of extendedspectrum βlactamases (blaTEM, blaSHV, blaCTXM1like, blaCTXM2like, blaCTXM8like, and blaCTXM9like)were detected, multidrugresistance organismrelated class I integron encoding gene blainT1 was also detected. ResultsSeven CRE strains were isolated in 2014-2015, isolation rate was 0.30%, strain 16 was Klebsiella pneumoniae, strains 7 was Citrobacter freundii, all 7 strains were resistant to βlactamase inhibitor compound, cephalosporins, cephamicins, and carbapenems, 3 strains were sensitive to amikacin and tetracycline, 2 strains were sensitive to compound sulfamethoxazole. 3, 2, 5, 7, 1, 4, and 5 strains of CRE were detected carrying blaNDM1, blaKPC2, blaTEM, blaSHV,blaCTXM1like, blaCTXM9like,and blainT1 respectively, no strain was found to carry blaCTXM2like and blaCTXM8like genes. ConclusionblaNDM1 and blaKPC2 are important mechanisms leading to carbapenem resistance of 7 CRE strains; blaTEM, blaSHV, and blaCTXM9like are important mechanism leading to cephalosporin resistance, blainT1 plays an important role in multidrugresistance to CRE and spread of multidrugresistant genes.