A #MDR #Plasmid pIMP26, Carrying blaIMP-26, fosA5, blaDHA-1, and qnrB4 in #Enterobacter cloacae (Sci Rep., abstract)

[Source: Scientific Reports, full page: (LINK). Abstract, edited.]

Article | OPEN | Published: 15 July 2019

A Multidrug Resistance Plasmid pIMP26, Carrying blaIMP-26, fosA5, blaDHA-1, and qnrB4 in Enterobacter cloacae

Su Wang,  Kaixin Zhou, Shuzhen Xiao, Lianyan Xie, Feifei Gu, Xinxin Li, Yuxing Ni, Jingyong Sun & Lizhong Han

Scientific Reports, volume 9, Article number: 10212 (2019)



IMP-26 was a rare IMP variant with more carbapenem-hydrolyzing activities, which was increasingly reported now in China. This study characterized a transferable multidrug resistance plasmid harboring blaIMP-26 from one Enterobacter cloacae bloodstream isolate in Shanghai and investigated the genetic environment of resistance genes. The isolate was subjected to antimicrobial susceptibility testing and multilocus sequence typing using broth microdilution method, Etest and PCR. The plasmid was analyzed through conjugation experiments, S1-nuclease pulsed-field gel electrophoresis and hybridization. Whole genome sequencing and sequence analysis was conducted for further investigation of the plasmid. E. cloacae RJ702, belonging to ST528 and carrying blaIMP-26, blaDHA-1, qnrB4 and fosA5, was resistant to almost all β-lactams, but susceptible to quinolones and tigecycline. The transconjugant inherited the multidrug resistance. The resistance genes were located on a 329,420-bp IncHI2 conjugative plasmid pIMP26 (ST1 subtype), which contained trhK/trhV, tra, parA and stbA family operon. The blaIMP-26 was arranged following intI1. The blaDHA-1 and qnrB4cluster was the downstream of ISCR1, same as that in p505108-MDR. The fosA5 cassette was mediated by IS4. This was the first report on complete nucleotide of a blaIMP-26-carrying plasmid in E. cloacae in China. Plasmid pIMP26 hosted high phylogenetic mosaicism, transferability and plasticity.

Keywords: Antibiotics; Drugs Resistance; Carbapenem; Beta-lactams; Enterobacter cloacae; Shanghai; China; Quinolones; Tigecycline.



Novel #carbapenemase FLC-1 and IMI-2 encoded by an #Enterobacter cloacae complex isolated from #food products (Antimicrob Agents Chemother., abstract)

[Source: Antimicrobial Agents and Chemotherapy, full page: (LINK). Abstract, edited.]

Novel carbapenemase FLC-1 and IMI-2 encoded by an Enterobacter cloacae complex isolated from food products

Michael S.M. Brouwer, Kamaleddin H. M. E. Tehrani, Michel Rapallini, Yvon Geurts, Arie Kant, Frank Harders, Vida Mashayekhi, Nathaniel I. Martin, Alex Bossers, Dik J. Mevius, Ben Wit,Kees T. Veldman

DOI: 10.1128/AAC.02338-18



Food for human consumption is screened widely for the presence of antibiotic resistant bacteria to assess the potential for transfer of resistant bacteria to the general population. Here, we describe an Enterobacter cloacae complex isolated from imported seafood which encodes two carbapenemases. Both enzymes belong to the Ambler class A β-lactamases, the previously described IMI-2 and a novel family designated FLC-1. The hydrolytic activity of the novel enzyme against aminopenicillins, cephalosporins and carbapenems was determined.

Copyright © 2019 Brouwer et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Keywords: Antibiotics; Drugs Resistance; Enterobacter cloacae; Carbapenem; Food safety.


Characterization of a #blaIMP-4-carrying #plasmid from #Enterobacter cloacae of #swine origin (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

Characterization of a blaIMP-4-carrying plasmid from Enterobacter cloacae of swine origin

Yao Zhu, Wanjiang Zhang, Stefan Schwarz, Changzhen Wang, Wenyu Liu, Fuguang Chen, Tian Luan, Siguo Liu

Journal of Antimicrobial Chemotherapy, dkz107, https://doi.org/10.1093/jac/dkz107

Published: 16 March 2019




To characterize an MDR blaIMP-4-harbouring plasmid from Enterobacter cloacae EC62 of swine origin in China.


Plasmid pIMP-4-EC62 from E. cloacae EC62 was transferred by conjugation via filter mating into Escherichia coli J53. Plasmid DNA was extracted from an E. coliJ53 transconjugant and sequenced using single-molecule real-time (SMRT) technology. MIC values for both the isolate EC62 and the transconjugant were determined using the broth microdilution and agar dilution methods. Plasmid stability in both the isolate EC62 and the transconjugant was assessed through a series of passages on antibiotic-free media.


Plasmid pIMP-4-EC62 is 314 351 bp in length, encodes 369 predicted proteins and harbours a novel class 1 integron carrying blaIMP-4 and a group II intron. The blaIMP-4-bearing plasmid belongs to the IncHI2/ST1 incompatibility group. Sequence analysis showed that pIMP-4-EC62 carries four MDR regions and several gene clusters encoding heavy metal resistance. Plasmid pIMP-4-EC62 was stably maintained in both the E. cloacae EC62 isolate and the transconjugant E. coli J53-pIMP-4-EC62 in the absence of selective pressure. Analysis of the evolutionary relatedness of selected IncHI2 plasmids indicates that ST1-type plasmids are key carriers of carbapenemase genes among IncHI2 plasmids.


pIMP-4-EC62 represents the first fully sequenced IncHI2-type blaIMP-4-harbouring plasmid from E. cloacae in China. Co-location of blaIMP-4 with other resistance genes on an MDR plasmid is likely to further accelerate the dissemination of blaIMP-4 by co-selection among bacteria from humans, animals and the environment under the selective pressure of other antimicrobial agents, heavy metals and disinfectants.


© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Antibiotics; Drugs Resistance; Plasmids; Enterobacter cloacae; Pigs; China.


The co-identification of #mcr-4.6 and #blaNDM-1 in a clinical #Enterobacter cloacae isolate from #China (Antimicrob Agents Chemother., abstract)

[Source: Antimicrobial Agents and Chemotherapy, full page: (LINK). Abstract, edited.]

The co-identification of mcr-4.6 and blaNDM-1 in a clinical Enterobacter cloacae isolate from China

Bhakti Chavda1, Jingnan Lv2, Mengyun Hou3, Kalyan D. Chavda1, Barry N. Kreiswirth1, Youjun Feng3*, Liang Chen1* and  Fangyou Yu4*

Author Affiliations: 1 Public Health Research Institute Center, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103; 2 Department of Laboratory Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; 3 Department of Medical Microbiology and Parasitology and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China; 4 Department of Clinical Laboratory, Shanghai Pulmonary Hospital, Tongji University, School of Medicine. Shanghai 200001, China



Here we describe the first report of a clinical colistin-resistant ST84 Enterobacter cloacae isolate co-harboring mcr-4.6 (previously named mcr-4.2) and blaNDM-1from a patient in China. The blaNDM-1-harboring IncX3 plasmid and the novel mcr-4.6-harboring ColE plasmid were completely sequenced. Although this isolate showed high level resistance to colistin, mcr-4.6 plasmid transformation, gene subcloning, susceptibility testing and lipid A matrix-assisted laser desorption ionization mass spectrometry analysis indicate that mcr-4.6 itself doesn’t confer resistance to colistin.



* Correspondence: Liang Chen, Chen11@njms.rutgers.edu or Fangyou Yu, wzjxyfy@163.com or Youjun Feng, fengyj@zju.edu.cn

Copyright © 2018 American Society for Microbiology. All Rights Reserved.

Keywords: Antibiotics; Drugs Resistance; Colistin; MCR4.6; China.


Novel #Enterobacter #Lineage as Leading Cause of #Nosocomial #Outbreak Involving #Carbapenemase-Producing Strains (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 24, Number 8—August 2018 / Research

Novel Enterobacter Lineage as Leading Cause of Nosocomial Outbreak Involving Carbapenemase-Producing Strains

Racha Beyrouthy, Marion Barets, Elodie Marion, Cédric Dananché, Olivier Dauwalder, Frédéric Robin, Lauraine Gauthier, Agnès Jousset, Laurent Dortet, François Guérin, Thomas Bénet, Pierre Cassier, Philippe Vanhems1, and Richard Bonnet1

Author affiliations: Centre Hospitalier Universitaire, Clermont-Ferrand, France (R. Beyrouthy, F. Robin, R. Bonnet); Centre National de Référence de la Résistance aux Antibiotiques, Clermont-Ferrand (R. Beyrouthy, F. Robin, R. Bonnet); Université Clermont Auvergne, Clermont-Ferrand (R. Beyrouthy, F. Robin, R. Bonnet); Institut National de la Santé et de la Recherche Médicale, Clermont-Ferrand (R. Beyrouthy, F. Robin, R. Bonnet); Institut National de la Recherche Agronomique, Clermont-Ferrand (R. Beyrouthy, F. Robin, R. Bonnet); Hôpital Édouard Herriot, Hospices Civils de Lyon, Lyon, France (M. Barets, E. Marion, C. Dananché, T. Bénet, P. Cassier, P. Vanhems); Groupement Hospitalier Est, Hospices Civils de Lyon, Lyon, France (O. Dauwalder); Centre International de Recherche en Infectiologie, Lyon (O. Dauwalder, T. Bénet, P. Vanhems),; Centre Hospitalier Universitaire Bicêtre, Paris, France (L. Gauthier, A. Jousset, L. Dortet); Centre National de Référence Associé de la Résistance aux Antibiotiques, Paris (L. Gauthier, A. Jousset, L. Dortet); Centre Hospitalier Universitaire, Caen, France (F. Guérin)



We investigated unusual carbapenemase-producing Enterobacter cloacae complex isolates (n = 8) in the novel sequence type (ST) 873, which caused nosocomial infections in 2 hospitals in France. Whole-genome sequence typing showed the 1-year persistence of the epidemic strain, which harbored a blaVIM-4 ST1-IncHI2 plasmid, in 1 health institution and 2 closely related strains harboring blaCTX-M-15 in the other. These isolates formed a new subgroup in the E. hormaechei metacluster, according to their hsp60 sequences and phylogenomic analysis. The average nucleotide identities, specific biochemical properties, and pangenomic and functional investigations of isolates suggested isolates of a novel species that had acquired genes associated with adhesion and mobility. The emergence of this novel Enterobacter phylogenetic lineage within hospitals should be closely monitored because of its ability to persist and spread.

Keywords: Antibiotics; Drugs Resistance; Carbapenem; Enterobacter cloacae; Nosocomial Outbreaks; Enterobacter hormaechei.


#Antimicrobial susceptibility and molecular epidemiology of clinical #Enterobacter cloacae #bloodstream isolates in #Shanghai, China (PLoS One, abstract)

[Source: PLoS One, full page: (LINK). Abstract, edited.]

Open Access / Peer-reviewed / Research Article

Antimicrobial susceptibility and molecular epidemiology of clinical Enterobacter cloacae bloodstream isolates in Shanghai, China

Su Wang , Shu-Zhen Xiao , Fei-Fei Gu, Jin Tang, Xiao-Kui Guo, Yu-Xing Ni, Jie-Ming Qu , Li-Zhong Han

Published: December 15, 2017 / DOI: https://doi.org/10.1371/journal.pone.0189713




Enterobacter cloacae is a major nosocomial pathogen causing bloodstream infections. We retrospectively conducted a study to assess antimicrobial susceptibility and phylogenetic relationships of E. cloacae bloodstream isolates in two tertiary university-affiliated hospitals in Shanghai, in order to facilitate managements of E. cloacae bloodstream infections and highlight some unknowns for future prevention.


Fifty-three non-duplicate E. cloacae bloodstream isolates were consecutively collected from 2013 to 2016. Antimicrobial susceptibility was determined by disk diffusion. PCR was performed to detect extended-spectrum β-lactamase (ESBL), carbapenemase and colistin resistance (MCR-1) gene. Plasmid-mediated AmpC β-lactamase (pAmpC) genes were detected using a multiplex PCR assay targeting MIR/ACT gene (closely related to chromosomal EBC family gene) and other plasmid-mediated genes, including DHA, MOX, CMY, ACC, and FOX. eBURST was applied to analyze multi-locus sequence typing (MLST).


The rates of resistance to all tested antibiotics were <40%. Among 53 E. cloacae isolates, 8(15.1%) were ESBL producers, 3(5.7%) were carbapenemase producers and 18(34.0%) were pAmpC producers. ESBL producers bear significantly higher resistance to cefotaxime (100.0%), ceftazidime (100.0%), aztreonam (100.0%), piperacillin (87.5%), tetracycline (75.0%), and trimethoprim-sulfamethoxazole (62.5%) than non-producers (p<0.05). PAmpC- and non-producers both presented low resistance rates (<40%) to all antibiotics (p>0.05). SHV (6/8, 75.0%) and MIR/ACT (15/18, 83.3%) predominated in ESBL and pAmpC producers respectively. Moreover, 2 isolates co-carried TEM-1, SHV-12, IMP-26 and DHA-1. MLST analysis distinguished the 53 isolates into 51 STs and only ST414 and ST520 were assigned two isolates of each (2/53).


The antimicrobial resistance rates were low among 53 E. cloacae bloodstream isolates in the two hospitals. Multiclonality disclosed no evidence on spread of these isolates in Shanghai. The simultaneous presence of ESBL, carbapenemase and pAmpC detected in 2 isolates was firstly reported in Shanghai, which necessitated active ongoing surveillances and consistent prevention and control of E. cloacae.


Citation: Wang S, Xiao S-Z, Gu F-F, Tang J, Guo X-K, Ni Y-X, et al. (2017) Antimicrobial susceptibility and molecular epidemiology of clinical Enterobacter cloacae bloodstream isolates in Shanghai, China. PLoS ONE 12(12): e0189713. https://doi.org/10.1371/journal.pone.0189713

Editor: Massimiliano Galdiero, Seconda Universita degli Studi di Napoli, ITALY

Received: August 22, 2017; Accepted: November 30, 2017; Published: December 15, 2017

Copyright: © 2017 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files.

Funding: This work was supported by the Special Fund for Health-scientific Research in the Public Interest of China Program (201002021) to Yu-Xing Ni, the National Natural Science Foundation of China (81472010) to Yu-Xing Ni and the Shanghai Three-Year Plan of the Key Subjects Construction in Public Health-Infectious Diseases and Pathogenic Microorganism (15GWZK0102). The funders had no role in study design, data collection and analysis, preparation of the manuscript or decision for publication.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Enterobacter Cloacae; Bacteremia; China; Antibiotics; Drugs Resistance.