#Plasmid-Mediated #mcr-1 #Colistin #Resistance in #Escherichia coli from a Black Kite in #Russia (Antimicrob Agents Chemother., abstract)

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

Plasmid-Mediated mcr-1 Colistin Resistance in Escherichia coli from a Black Kite in Russia

Hassan Tarabai, Adam Valcek, Ivana Jamborova, Sergey V. Vazhov, Igor V. Karyakin, Rainer Raab, Ivan Literak, Monika Dolejska

DOI: 10.1128/AAC.01266-19

 

ABSTRACT

The gene mcr-1 conferring resistance to last-line antibiotic colistin has been reported globally. Here we describe the first detection of plasmid-mediated colistin resistance in Russian wildlife, an isolate of Escherichia coli sequence type 2280 from a black kite (Milvus migrans), scavenging raptor. Whole genome sequencing and plasmid transferability experiments revealed that mcr-1.1 was located on a conjugative IncI2 plasmid pDR164 (59891 bp). Migratory Black Kites may contribute to the global spread of mobile colistin resistance.

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

Keywords: Antibiotics; Drugs Resistance; Colistin; MCR1; E. Coli; Wild Birds; Russia.

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#Synergistic #combinations and repurposed #antibiotics active against the #pandrug #resistant #Klebsiella pneumoniae #Nevada strain (Antimicrob Agents Chemother., abstract)

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

Synergistic combinations and repurposed antibiotics active against the pandrug-resistant Klebsiella pneumoniae Nevada strain

Thea Brennan-Krohn [MD], James E. Kirby [MD]

DOI: 10.1128/AAC.01374-19

 

ABSTRACT

In early 2017, the Centers for Disease Control and Prevention issued an alarming report describing a woman in Nevada who died in the setting of infection with a pan-resistant Klebsiella pneumoniae isolate that harbored an NDM-1 enzyme (AR-0636) and was colistin resistant as a result of inactivation of the mgrB regulator gene (1, 2).…

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

Keywords: Antibiotics; Drugs Resistance; Klebsiella pneumoniae; USA; Nevada.

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#Resistance to critically important #antimicrobials in #Australian silver #gulls (Chroicocephalus novaehollandiae) and evidence of #anthropogenic origins (J Antimicrob Chemother., abstract)

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

Resistance to critically important antimicrobials in Australian silver gulls (Chroicocephalus novaehollandiae) and evidence of anthropogenic origins

Shewli Mukerji, Marc Stegger, Alec Vincent Truswell, Tanya Laird, David Jordan, Rebecca Jane Abraham, Ali Harb, Mary Barton, Mark O’Dea, Sam Abraham

Journal of Antimicrobial Chemotherapy, dkz242, https://doi.org/10.1093/jac/dkz242

Published: 09 July 2019

 

Abstract

Objectives

Antimicrobial resistance (AMR) to critically important antimicrobials (CIAs) amongst Gram-negative bacteria can feasibly be transferred amongst wildlife, humans and domestic animals. This study investigated the ecology, epidemiology and origins of CIA-resistant Escherichia coli carried by Australian silver gulls (Chroicocephalus novaehollandiae), a gregarious avian wildlife species that is a common inhabitant of coastal areas with high levels of human contact.

Methods

Sampling locations were widely dispersed around the perimeter of the Australian continent, with sites separated by up to 3500 km. WGS was used to study the diversity and molecular characteristics of resistant isolates to ascertain their epidemiological origin.

Results

Investigation of 562 faecal samples revealed widespread occurrence of extended-spectrum cephalosporin-resistant (21.7%) and fluoroquinolone-resistant (23.8%) E. coli. Genome sequencing revealed that CIA-resistant E. coliisolates (n = 284) from gulls predominantly belonged to human-associated extra-intestinal pathogenic E. coli (ExPEC) clones, including ST131 (17%), ST10 (8%), ST1193 (6%), ST69 (5%) and ST38 (4%). Genomic analysis revealed that gulls carry pandemic ExPEC-ST131 clades (O25:H4 H30-R and H30-Rx) and globally emerging fluoroquinolone-resistant ST1193 identified among humans worldwide. Comparative analysis revealed that ST131 and ST1193 isolates from gulls overlapped extensively with human clinical isolates from Australia and overseas. The present study also detected single isolates of carbapenem-resistant E. coli (ST410-blaOXA-48) and colistin-resistant E. coli (ST345-mcr-1).

Conclusions

The carriage of diverse CIA-resistant E. coli clones that strongly resemble pathogenic clones from humans suggests that gulls can act as ecological sponges indiscriminately accumulating and disseminating CIA-resistant bacteria over vast distances.

Topic: colistin – epidemiology – animals, domestic – australia – aves – clone cells – disease transmission – drug resistance, microbial – ecology – feces – fluoroquinolones – genome – gram-negative bacteria – intestines – prescriptions, drug – surgical sponges – bacteria – silver – antimicrobials – escherichia coli – pandemics – genome sequencing – carbapenem resistance – extraintestinal pathogenic escherichia coli – whole genome sequencing

Issue Section: ORIGINAL RESEARCH

© 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; Carbapenem; Colistin; Fluoroquinolones; MCR1; E.Coli; Wild Birds; Australia.

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#mcr-9, an inducible #gene encoding an acquired phosphoethanolamine transferase in #Escherichia coli, and its origin (Antimicrob Agents Chemother., abstract)

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

mcr-9, an inducible gene encoding an acquired phosphoethanolamine transferase in Escherichia coli, and its origin

Nicolas Kieffer, Guilhem Royer, Jean-Winoc Decousser, Anne-Sophie Bourrel, Mattia Palmieri, Jose-Manuel Ortiz De La Rosa, Hervé Jacquier, Erick Denamur, Patrice Nordmann,Laurent Poirel

DOI: 10.1128/AAC.00965-19

 

ABSTRACT

The plasmid-located mcr-9 gene encoding a putative phosphoethanolamine transferase was identified in a colistin-resistant human fecal Escherichia coli belonging to a very rare phylogroup D-ST69-O15:H6 clone. This MCR-9 protein shares 33-65% identity with the other plasmid-encoded MCR-type enzymes identified (MCR-1- to -8) that have been found as sources of acquired resistance to polymyxins in Enterobacteriaceae. Analysis of the lipopolysaccharide of the MCR-9-producing isolate revealed a similar function as MCR-1 by adding a phosphoethanolamine group to the lipid A and subsequently modifying the structure of the lipopolysaccharide. However, a minor impact on susceptibility to polymyxins was noticed once cloned and produced in an E. coli K-12 derived strain. Nevertheless, we showed here that sub-inhibitory concentrations of colistin induced the expression of the mcr-9 gene, leading to increased MIC levels. This inducible expression was mediated by a two-component regulatory system encoded by the qseC and qseB genes located downstream of mcr-9. Genetic analysis showed that the mcr-9 gene was carried by an IncHI2 plasmid. In silico analysis revealed that the plasmid-encoded MCR-9 shared significant amino acid identity (ca. 80%) with the chromosomally-encoded MCR-like proteins from Buttiauxella spp. In particular, Buttiauxella gaviniae was found to harbor a gene encoding MCR-BG, sharing 84% identity with MCR-9. That gene was neither expressed nor inducible in its original host, which was fully susceptible to polymyxins. This work showed that mcr genes may circulate quite silently and remaining undetected unless induced by colistin.

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

Keywords: Antibiotics; Drugs Resistance; MCR9; Colistin; E. Coli.

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Eliminating #mcr1-harbouring #plasmids in #clinical isolates using the #CRISPR/Cas9 system (J Antimicrob Chemother., abstract)

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

Eliminating mcr-1-harbouring plasmids in clinical isolates using the CRISPR/Cas9 system

Pengxia Wang, Dongmei He, Baiyuan Li, Yunxue Guo, Weiquan Wang, Xiongjian Luo, Xuanyu Zhao, Xiaoxue Wang

Journal of Antimicrobial Chemotherapy, dkz246, https://doi.org/10.1093/jac/dkz246

Published: 15 June 2019

 

Abstract

Objectives

To eliminate mcr-1-harbouring plasmids and MDR plasmids in clinical Escherichia coli isolates.

Methods

Plasmid pMBLcas9 expressing Cas9 was constructed and used to clone target single-guide RNAs (sgRNAs) for plasmid curing. The recombinant plasmid pMBLcas9-sgRNA was transferred by conjugation into two clinical E. coliisolates. The curing efficiency of different sgRNAs targeting conserved genes was tested. The elimination of targeted plasmids and the generation of transposase-mediated recombination of p14EC033a variants were characterized by PCR and DNA sequencing.

Results

In this study, four native plasmids in isolate 14EC033 and two native plasmids in isolate 14EC007 were successfully eliminated in a step-by-step manner using pMBLcas9. Moreover, two native plasmids in 14EC007 were simultaneously eliminated by tandemly cloning multiple sgRNAs in pMBLcas9, sensitizing 14EC007 to polymyxin and carbenicillin. In 14EC033 with two mcr-1-harbouring plasmids, IncI2 plasmid p14EC033a and IncX4 plasmid p14EC033b, a single mcr-1 sgRNA mediated the loss of p14EC033b and generated a mutant p14EC033a in which the mcr-1 gene was deleted. An insertion element, IS5, located upstream of mcr-1 in p14EC033a was responsible for transposase-mediated recombination, resulting in mcr-1 gene deletion instead of plasmid curing.

Conclusions

CRISPR/Cas9 can be used to efficiently sensitize clinical isolates to antibiotics in vitro. For isolates with multiple plasmids, the CRISPR/Cas9 approach can either remove each plasmid in a stepwise manner or simultaneously remove multiple plasmids in one step. Moreover, this approach can be used to delete multiple gene copies by using only one sgRNA. However, caution must be exercised to avoid unwanted recombination events during genetic manipulation.

Topic: plasmids – crispr

Issue Section: ORIGINAL RESEARCH

Keywords: Antibiotics; Drugs Resistance; MCR1; Colistin; CRISPR.

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Co-Occurrence of #mcr-1 and qnrS1 on an IncHI2 #Plasmid in #Clinical Isolates of #SalmonellaTyphimurium in #Spain (Vector Borne Zoo Dis., abstract)

[Source: Vector Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Co-Occurrence of mcr-1 and qnrS1 on an IncHI2 Plasmid in Clinical Isolates of SalmonellaTyphimurium in Spain

Teresa Trujillo-Soto, Jesús Machuca, Jorge Arca-Suárez, Manuel Rodríguez-Iglesias, and Fátima Galán-Sánchez

Published Online: 30 May 2019 / DOI: https://doi.org/10.1089/vbz.2018.2398

 

Abstract

Salmonella enterica is a well-adapted zoonotic bacterium associated to cases of gastroenteritis and bacteremia with increased morbidity and mortality. In this study, three isolates of Salmonella Typhimurium obtained from human clinical samples, showing colistin resistance and low-level resistance to quinolones, have been genetically characterized. We detected the co-occurrence of mcr-1 and qnrS1 on a single IncHI2 plasmid in isolates of Salmonella Typhimurium obtained from Spanish children without a travel history. The multiresistant region contained numerous resistance genes. Isolates were clonally related, which suggests the presence of these clones in the community and the potential to cause outbreaks affecting the most susceptible population. It is necessary to monitor the presence of these plasmid-mediated resistance genes in human European strains of Salmonella spp. because of the risk of producing outbreaks of community-acquired infections.

Keywords: Antibiotics; Drugs Resistance; Colistin; Quinolones; Salmonella Typhimurium; Spain.

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Emergence of #mcr-8.2-bearing #Klebsiella quasipneumoniae of #animal origin (J Antimicrob Chemother., abstract)

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

Emergence of mcr-8.2-bearing Klebsiella quasipneumoniae of animal origin

Xiaorong Yang, Li Liu, Zhiqiang Wang, Li Bai, Ruichao Li

Journal of Antimicrobial Chemotherapy, dkz213, https://doi.org/10.1093/jac/dkz213

Published: 16 May 2019

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Sir,

The emergence of plasmid-mediated mcr-1, conferring resistance to colistin, which is considered as a last-resort drug to treat carbapenem-resistant Enterobacteriaceae (CRE) infections, poses a severe public health concern.1 Eight different mcr genes mainly mediated by plasmids were identified within 3 years after the reporting of mcr-1 in late 2015.1,2,Klebsiella pneumoniae is a well-known bacterium causing life-threatening infections, especially in neonates, the elderly and immunocompromised individuals.3 The mcr-1, mcr-3, mcr-7 and mcr-8 genes have been detected in K. pneumoniae recently.2,4,Klebsiella quasipneumoniae, which is found in animals and…

(…)

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© 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; Colistin; Klebsiella pneumoniae; MCR8.

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