New Delhi Metallo-β-Lactamase 1(NDM-1), the Dominant Carbapenemase Detected in Carbapenem-Resistant Enterobacter cloacae from Henan Province, China.
The emergence of New Delhi metallo-β-lactamase 1 (NDM-1) has become established as a major public health threat and represents a new challenge in the treatment of infectious diseases. In this study, we report a high incidence and endemic spread of NDM-1-producing carbapenem-resistant Enterobacter cloacae isolates in Henan province, China. Eight (72.7%) out of eleven non-duplicated carbapenem-resistant E. cloacae isolates collected between June 2011 and May 2013 were identified as NDM-1 positive. The blaNDM-1 gene surrounded by an entire ISAba125 element and a bleomycin resistance gene bleMBL in these isolates were carried by diverse conjugatable plasmids (IncA/C, IncN, IncHI2 and untypeable) ranging from ~55 to ~360 kb. Molecular epidemiology analysis revealed that three NDM-1-producing E. cloacae belonged to the same multilocus sequence type (ST), ST120, two of which were classified as extensively drug-resistant (XDR) isolates susceptible only to tigecycline and colistin. The two XDR ST120 E. cloacae isolates co-harbored blaNDM-1, armA and fosA3 genes and could transfer resistance to carbapenems, fosfomycin and aminoglycosides simultaneously via a conjugation experiment. Our study demonstrated NDM-1 was the most prevalent metallo-β-lactamase (MBL) among carbapenem-resistant E.cloacae isolates and identified a potential endemic clone of ST120 in Henan province. These findings highlight the need for enhanced efforts to monitor the further spread of NDM-1 and XDR ST120 E. cloacae in this region.
Department of clinical laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China; Henan province Key Laboratory of Medicine, Zhengzhou, PR China.
Cailin
C
Liu
School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, PR China.
Shangshang
S
Qin
Department of clinical laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China; Henan province Key Laboratory of Medicine, Zhengzhou, PR China.
Hui
H
Xu
Department of clinical laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China; Henan province Key Laboratory of Medicine, Zhengzhou, PR China.
Lijuan
L
Xu
School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, PR China.
Di
D
Zhao
Department of clinical laboratory, The central hospital of Zhumadian city, Zhumadian, PR China.
Xuchun
X
Liu
Department of clinical laboratory, The central hospital of Sanmenxia city, Sanmenxia, PR China.
Shaolei
S
Lang
Department of clinical laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China; Henan province Key Laboratory of Medicine, Zhengzhou, PR China.
Xianju
X
Feng
School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, PR China.
Hong-Min
HM
Liu
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D016972:Enterobacter cloacae / Q000187:drug effects* / Q000235:genetics*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000235:genetics; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1