Conjugative IncX 1 #plasmid harboring #colistin #resistance gene #mcr-5.1 in #E coli isolated from #chicken rice retailed in #Singapore (Antimicrob Agents Chemother., abstract)

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

Conjugative IncX 1 plasmid harboring colistin resistance gene mcr-5.1 in E. coli isolated from chicken rice retailed in Singapore

Siyao Guo, Moon Y.F. Tay, Aung Kyaw Thu, Kelyn Lee Ghee Seow, Yang Zhong, Lee Ching Ng, Joergen Schlundt

DOI: 10.1128/AAC.01043-19



Colistin is regarded as one of the last resort antimicrobials to Gram-negative bacterial infection (1).…


Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Antibiotics; Drugs Resistance; Colistin; MCR5; Plasmids; Food Safety; Singapore.


Detection of a novel #mcr-5.4 gene variant in #hospital tap #water by shotgun #metagenomic sequencing (J Antimicrob Chemother., summary)

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

Detection of a novel mcr-5.4 gene variant in hospital tap water by shotgun metagenomic sequencing

Giuseppe Fleres, Natacha Couto, Leonard Schuele, Monika A Chlebowicz,Catarina I Mendes, Luc W M van der Sluis, John W A Rossen, Alex W Friedrich,Silvia García-Cobos

Journal of Antimicrobial Chemotherapy, dkz363,

Published: 23 August 2019

Issue Section: Research letter



Colistin is considered a last-resort antibiotic for treating serious infections caused by MDR Gram-negative bacteria. The efficacy of this antibiotic is challenged by the emergence and global spread of mobile colistin resistance (mcr) determinants, which threaten human, animal and environmental health. The first mobile colistin resistance gene (mcr-1) was reported in 2015 and since then up to eight different variants have been described.1 In 2017, Borowiak et al.2 described a new transposon-associated phosphoethanolamine transferase mediating colistin resistance, named mcr-5, in d-tartrate-fermenting Salmonella enterica subsp. enterica serovar Paratyphi B isolated from poultry. The mcr-5.3 variant has been recently reported in Stenotrophomonas spp. from sewage water.3 Here we report for the first time (to the best of our knowledge) the detection of an mcr-5 gene in a hospital water environment using short-read metagenomic sequencing (SRMseq) and subsequent characterization using long-read metagenomic sequencing (LRMseq) to reveal its genetic environment.




We would like to thank Erwin C. Raangs for technical assistance.


This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement 713660 (MSCA-COFUND-2015-DP ‘Pronkjewail’), which includes in-kind contributions by commercial partners. None of the commercial partners had any influence on interpretation of reviewed data and conclusions drawn, or on drafting of the manuscript. This work was partly supported by the INTERREG VA (202085)-funded project EurHealth-1Health, part of a Dutch–German cross-border network supported by the European Commission, the Dutch Ministry of Health, Welfare and Sport (VWS), the Ministry of Economy, Innovation, Digitalization and Energy of the German Federal State of North Rhine-Westphalia and the German Federal State of Lower Saxony.

Transparency declarations

None to declare.

Keywords: Antibiotics; Drugs Resistance; Colistin; MCR5; Germany.


Functional characterization of a Miniature Inverted Transposable Element at the origin of #mcr-5 gene acquisition in #Escherichia coli (Antimicrob Agents Chemother., abstract)

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

Functional characterization of a Miniature Inverted Transposable Element at the origin of mcr-5 gene acquisition in Escherichia coli

Nicolas Kieffer, Patrice Nordmann, Yves Millemann, Laurent Poirel

DOI: 10.1128/AAC.00559-19



Plasmid-mediated colistin resistance of the MCR type is a growing concern in Enterobacteriaceae since it has been described worldwide either in humans and in animals. Here we identified a series of MCR-producing Escherichia coli isolates, corresponding to two different clones (respectively represented by isolates PS1 and PS8b) producing MCR-1 and MCR-5, respectively, from pig fecal samples in France. Plasmid analysis showed that the plasmid carrying the mcr-1 gene (pPS1) possesses an IncHI2 backbone whereas the mcr-5gene was carried onto a 6,268 bp non-typeable, non self-conjugative plasmid (pPS8b). Detailed analysis of plasmid pPS8b revealed a 3,803 bp-long cassette containing the mcr-5 gene that was bracketed by two inverted-repeat sequences (IRs) with 5-bp long direct repeats at each extremity, similarly to an insertion sequence, but with the exception that no transposase gene was identified within this cassette. By performing in-vitro transposition experiments, we showed that the mcr-5 cassette could be mobilized by the TnAs1 transposase provided in-trans, displaying a similar mobilization mechanism as miniature inverted repeat transposable elements (MITEs).

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Antibiotics; Drugs Resistance; Colistin; E. Coli; MCR5; Plasmids.


Characterization of #mcr5 -harboring #Salmonella enterica subsp. enterica serovar #Typhimurium isolates from #animal and #food origin in #Germany (Antimicrob Agents Chemother., abstract)

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

Characterization of mcr-5-harboring Salmonella enterica subsp. entericaserovar Typhimurium isolates from animal and food origin in Germany

Maria Borowiak, Jens A. Hammerl, Carlus Deneke, Jennie Fischer, Istvan Szabo, Burkhard Malorny

DOI: 10.1128/AAC.00063-19



We characterized eight mcr-5 positive Salmonella Typhimurium ST34 isolates obtained from pig and meat in Germany. Five plasmid types were identified harboring mcr-5 on Tn6452 or putative mobile insertion cassettes. Mobility of mcr-5 was confirmed by integration of Tn6452into the bacterial chromosomes of two strains and the detection of conjugative mcr-5 plasmids. This bears a risk to enhance mcr-5 distribution.

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Antibiotics; Drugs Resistance; Colistin; MCR5; Salmonella typhimurium; Plasmids; Pigs; Food Safety; Germany.


Novel #mcr-5.3 variant in a CTX-M-8-producing #Escherichia coli ST711 isolated from an infected #horse (J Antimicrob Chemother., abstract)

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

Novel mcr-5.3 variant in a CTX-M-8-producing Escherichia coli ST711 isolated from an infected horse

Miriam R Fernandes, Louise Cerdeira, Meire M Silva, Fábio P Sellera, Maria Muñoz, Felicio G Junior, Sergio S Azevedo, Pablo Power, Gabriel Gutkind, Nilton Lincopan

Journal of Antimicrobial Chemotherapy, dky341,

Published: 07 September 2018



Following the first description of the mobile phosphoethanolamine transferase gene mcr-1, responsible for transferable colistin resistance in Enterobacteriaceae of human and animal origin, a rapid dissemination and emergence of novel mcr variants has been globally described.1–5 

In this regard, two recent reports published in JAC have documented the identification of novel mcr-5 and mcr-5.2 gene variants in d-tartrate fermenting Salmonella enterica subsp. enterica serovar Paratyphi B and Escherichia coli from food and food-producing animals, respectively, in Germany.3,4

Interestingly, mcr-5 has also been identified in E. coli isolates from diseased pigs in Japan6 and from animals…


Issue Section: Research letter

© The Author(s) 2018. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email:

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (

Keywords: Antibiotics; Drugs Resistance; Colistin; MCR5; Horses.


Mobile #colistin #resistance gene #mcr5 in #porcine #Aeromonas hydrophila (J Antimicrob Chemother., abstract)

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

Mobile colistin resistance gene mcr-5 in porcine Aeromonas hydrophila

Shizhen Ma, Chengtao Sun, Anette Hulth, Jiyun Li, Lennart E Nilsson, Yuqing Zhou, Stefan Börjesson, Zhenwang Bi, Zhenqiang Bi, Qiang Sun, Yang Wang

Journal of Antimicrobial Chemotherapy, dky110,

Published: 11 April 2018




To characterize the mobile colistin resistance gene mcr-5 in Aeromonas hydrophila from backyard pigs in rural areas of China.


Pig faecal samples from 194 households were directly tested for the presence of mcr-5 by PCR assay and the phenotypic antimicrobial susceptibility profiles of the mcr-5-positive isolates were determined using the broth dilution method. The genomic location and transferability of mcr-5 were analysed by S1-PFGE with Southern blotting and DNA hybridization, and natural transformation, respectively. One strain isolated from an mcr-5-positive sample was subjected to WGS and the stability of the mcr-5-harbouring plasmid over successive generations was examined by subculturing.


One mcr-5-positive A. hydrophila isolate showing resistance, with a colistin MIC of 4 mg/L, was isolated from a backyard pig faecal sample. mcr-5 was located on a 7915 bp plasmid designated pI064-2, which could naturally transform into a colistin-susceptible A. hydrophila strain of porcine origin and mediated colistin resistance in both the original isolate and its transformants. The plasmid backbone (3790 bp) of pI064-2 showed 81% nucleotide sequence identity to the corresponding region of the ColE2-type plasmid pAsa1 from Aeromonas salmonicida, while similar replication primases are widely distributed among aeromonads, Enterobacteriaceae and Pseudomonas species.


To the best of our knowledge, this is the first identification of the novel colistin resistance gene mcr-5 in an A. hydrophila isolate from the faeces of a backyard pig. mcr-5 is expected to be able to disseminate among different bacterial species and genera.

Keywords: Antibiotics; Drugs Resistance; Pigs; Colistin; MCR5; Aeromonas Hydrophila.


Newly identified #colistin #resistance genes, #mcr4 and #mcr5, from upper and lower #alimentary #tract of #pigs and #poultry in #China (PLoS One, abstract)

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


Newly identified colistin resistance genes, mcr-4 and mcr-5, from upper and lower alimentary tract of pigs and poultry in China

Li Chen , Jilei Zhang , Jiawei Wang, Patrick Butaye, Patrick Kelly, Min Li, Feng Yang, Jiansen Gong, Afrah Kamal Yassin, Weina Guo, Jing Li, Chunlian Song, Chengming Wang

Published: March 14, 2018 / DOI:



Antimicrobial resistance against colistin has emerged worldwide threatening the efficacy of one of the last-resort antimicrobials used for the treatment of Enterobacteriaceae. To investigate the presence of the recently identified colistin resistance genes (mcr-4, mcr-5) in China, we established PCRs to detect mcr-4 and mcr-5 on 213 anal and 1,339 nasal swabs from apparently healthy pigs (n = 1,454) in nine provinces, and 1,696 cloacal and 1,647 oropharyngeal samples from poultry (n = 1,836) at live-bird markets in 24 provinces of China. The prevalence of the mcr-4 in swine swabs (41.4%; 642/1,552) was significantly higher than in swabs from poultry (11.5%; 384/3,343). The mcr-4 gene was found in geese (49.5%, 54/109), chickens (17.2%, 257/1,498), pigeons (17.2%, 17/99) and ducks (15.4%, 20/130). In a similar trend, the prevalence of the mcr-5 in swine swabs (33.1%; 514/1552) was significantly higher than in swabs from poultry (5.6%; 187/3,343). The mcr-5 was identified in geese (17.4%, 19/109), chickens (9.9%, 148/1,498), ducks (7.7%, 10/130) and pigeons (3%, 3/99). The mcr-4 prevalence in the nasal swabs from pigs (59.2%, 58/98) was significantly higher than that in anal swabs (29.6%, 29/98) (P<0.001). Similarly, the mcr-5 prevalence in the nasal swabs from pigs (61.2%, 60/98) was significantly higher than in anal swabs (44.9%, 44/98) (P = 0.02), and significantly higher in oropharyngeal swabs (7.2%, 109/1,507) than in the cloacal swabs (3.7%, 56/1,507) (P<0.001). This study further confirms the presence of the mcr-4 and mcr-5 in animals and indicates these genes are prevalent and widespread in food producing animals (pig and poultry) in China. Future studies are needed to characterize the bacteria carrying the mcr-4 and mcr-5 and their locations on plasmids and/or the bacterial chromosomes, and determine co-resistances in the mcr-4 and mcr-5 positive strains.


Citation: Chen L, Zhang J, Wang J, Butaye P, Kelly P, Li M, et al. (2018) Newly identified colistin resistance genes, mcr-4 and mcr-5, from upper and lower alimentary tract of pigs and poultry in China. PLoS ONE 13(3): e0193957.

Editor: Roman R. Ganta, Kansas State University, UNITED STATES

Received: January 1, 2018; Accepted: February 21, 2018; Published: March 14, 2018

Copyright: © 2018 Chen 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. All the nucleotide sequences were submitted to GenBank with accession numbers MG586909 to MG586912 for mcr-4 and MG586913 to MG586915 for mcr-5.

Funding: This work was supported by a grant from the National Key R & D Program of China (2016YFD0500804), a grant from the National Natural Science Foundation of China (NO: 31472225), the Priority Academic Program Development of Jiangsu Higher Education Institutions, and the Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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

Keywords: Antibiotics; Drugs Resistance; Colistin; Pigs; Poultry; China; MCR4; MCR5.