Objective      To investigate the characterization of resistance genes and molecular epidemiology of carbapenem-nonsusceptible (CNS) Enterobacter cloacae (E. cloacae) isolates in our hospital.       Methods      Antimicrobial susceptibility of 50 non-duplicated CNS E. cloacae isolates collected in 2012 was analyzed by VITEK2 Compact. Carbapenemase genes

extended spectrum β-lactamase (ESBL) genes

quinolone resistance determinants (QRDs)

aminoglycoside resistance determinants (ARDs) and class Ⅰ int

egrin (Intl1) were examined by PCR. Clonal relatedness was determined by pulsed-field gel electrophoresis (PFGE).       Results      Of the 50 isolates

2 (4%) harbored carbapenemase gene bla

IMP-8

and 41 (82%) carried ESBLs. There were 41 (82%) ESBL-positive isolates

41 (82%) QRD-positive isolates

37 (74%) ARD-positive isolates

and 20 (40%) Intl1-positive isolates. The 2 bla

IMP-8

-positive isolates harbored ESBLs

QRD genes and ARD genes. Of the 41 ESBL-positive isolates

40 (97.6%) were QRD-positive

and 33 (80.5%) were ARD-positive. PFGE showed that the 50 CNS E. cloacae isolates were devided into 21 different types.       Conclusion      QRD and ARD genes are highly prevalent among the CNS E. cloacae isolates in our hospital. Multi-drug resistant genes are co-expressed in the same isolates. Molecular epidemiology analysis reveals donal diversities in these 50 strains.