scholarly journals Plasmid-Mediated Novel blaNDM-17 Gene Encoding a Carbapenemase with Enhanced Activity in a Sequence Type 48 Escherichia coli Strain

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Zhihai Liu ◽  
Yang Wang ◽  
Timothy R. Walsh ◽  
Dejun Liu ◽  
Zhangqi Shen ◽  
...  

ABSTRACT Carbapenem-resistant Enterobacteriaceae (CRE) have spread worldwide, leaving very few treatment options available. New Delhi metallo-beta-lactamase (NDM) is the main carbapenemase mediating CRE resistance and is of increasing concern. NDM-positive Enterobacteriaceae of human origin are frequently identified; however, the emergence of NDM, and particularly novel variants, in bacteria of food animal origin has never been reported. Here, we characterize a novel NDM variant (assigned NDM-17) identified in a β-lactam-resistant sequence type 48 (ST48) Escherichia coli strain that was isolated from a chicken in China. Compared to NDM-1, NDM-17 had three amino acid substitutions (V88L, M154L, and E170K) that confer significantly enhanced carbapenemase activity. Compared to NDM-5, NDM-17 had only one amino acid substitution (E170K) and slightly increased isolate resistance to carbapenem, as indicated by increased MIC values. The gene encoding NDM-17 (bla NDM-17) was located on an IncX3 plasmid, which was readily transferrable to recipient E. coli strain J53 by conjugation, suggesting the possibility of the rapid dissemination of bla NDM-17. Enzyme kinetics showed that NDM-17 could hydrolyze all β-lactams tested, except for aztreonam, and had a significantly higher affinity for all β-lactams tested than did NDM-5. The emergence of this novel NDM variant could pose a threat to public health because of its transferability and enhanced carbapenemase activity.

2018 ◽  
Vol 6 (13) ◽  
Author(s):  
Jesus Tamariz ◽  
Carlos Llanos ◽  
Carlos Seas ◽  
Paola Montenegro ◽  
Jose Lagos ◽  
...  

ABSTRACT We present here the draft genome sequence of the first New Delhi metallo-β-lactamase (NDM-1)-producing Escherichia coli strain, belonging to sequence type 155 (ST155), isolated in Peru. Assembly of this draft genome resulted in 5,061,184 bp, revealing a clinically significant resistome for β-lactams, aminoglycosides, tetracyclines, phenicols, sulfonamides, trimethoprim, and fluoroquinolones.


2014 ◽  
Vol 58 (10) ◽  
pp. 6302-6305 ◽  
Author(s):  
Tatsuya Tada ◽  
Basudha Shrestha ◽  
Tohru Miyoshi-Akiyama ◽  
Kayo Shimada ◽  
Hiroshi Ohara ◽  
...  

ABSTRACTA novel New Delhi metallo-β-lactamase variant, NDM-12, was identified in a carbapenem-resistantEscherichia coliclinical isolate obtained from a urine sample from a patient in Nepal. NDM-12 differed from NDM-1 by two amino acid substitutions (M154L and G222D). The enzymatic activities of NDM-12 against β-lactams were similar to those of NDM-1, although NDM-12 showed lowerkcat/Kmratios for all β-lactams tested except doripenem. TheblaNDM-12gene was located in a plasmid of 160 kb.


2016 ◽  
Vol 60 (8) ◽  
pp. 5080-5084 ◽  
Author(s):  
Odette J. Bernasconi ◽  
Esther Kuenzli ◽  
João Pires ◽  
Regula Tinguely ◽  
Alessandra Carattoli ◽  
...  

ABSTRACTStool samples from 38 travelers returning from India were screened for extended-spectrum cephalosporin- and carbapenem-resistantEnterobacteriaceaeimplementing standard selective plates. Twenty-six (76.3%) people were colonized with CTX-M or DHA producers, but none of the strains was colistin resistant and/ormcr-1positive. Nevertheless, using overnight enrichment and CHROMagar Orientation plates supplemented with colistin, four people (10.5%) were found to be colonized with colistin-resistantEscherichia coli. One cephalosporin-susceptible sequence type 10 (ST10) strain carried a 4,211-bp ISApl1-mcr-1-ISApl1element in an IncHI2 plasmid backbone.


2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Ching-Hsun Wang ◽  
L. Kristopher Siu ◽  
Feng-Yee Chang ◽  
Yu-Kuo Tsai ◽  
Yi-Tsung Lin ◽  
...  

ABSTRACT We report the first clinical Escherichia coli strain EC3000 with concomitant chromosomal colistin and carbapenem resistance. A novel in-frame deletion, Δ6-11 (RPISLR), in pmrB that contributes to colistin resistance was verified using recombinant DNA techniques. Although being less fit than the wild-type (WT) strain or EC3000 revertant (chromosomal replacement of WT pmrB in EC3000), a portion of serially passaged EC3000 strains preserving colistin resistance without selective pressure raises the concern for further spread.


2016 ◽  
Vol 55 (1) ◽  
pp. 199-205 ◽  
Author(s):  
Ping Shen ◽  
Maoli Yi ◽  
Ying Fu ◽  
Zhi Ruan ◽  
Xiaoxing Du ◽  
...  

ABSTRACTNew Delhi metallo-β-lactamase-1 (NDM-1)-producingEnterobacteriaceaehas disseminated rapidly throughout the world and poses an urgent threat to public health. Previous studies confirmed that theblaNDM-1gene is typically carried in plasmids but rarely in chromosome. We discovered a multidrug-resistantEscherichia colistrain Y5, originating from a urine sample and containing theblaNDM-1gene, which did not transfer by either conjugation or electrotransformation. We confirmed the possibility of its chromosome location by S1-pulsed-field gel electrophoresis (PFGE) and XbaI-PFGE, followed by Southern blotting. To determine the genomic background ofblaNDM-1, the genome of Y5 was completely sequenced and compared to other reference genomes. The results of our study revealed that this isolate consists of a 4.8-Mbp chromosome and three plasmids, it is an epidemic clone of sequence type (ST) 167, and it shows 99% identity withEscherichia coli6409 (GenBank accession no.CP010371), which lacks the sameblaNDM-1gene-surrounding structure as Y5. TheblaNDM-1gene is embedded in the chromosome along with two tandem copies of an insertion sequence common region 1 (ISCR1) element (sul1-ARR-3-cat-blaNDM-1-bleo-ISCR1), which appears intact in the plasmid fromProteus mirabilis(GenBank accession no.KP662515). The genomic context indicates that the ISCR1element mediated theblaNDM-1transposition from a single source plasmid to the chromosome. Our study is the first report of anEnterobacteriaceaestrain harboring a chromosomally integratedblaNDM-1, which directly reveals the vertical spreading pattern of the gene. Close surveillance is urgently needed to monitor the emergence and potential spread of ST167 strains that harborblaNDM-1.


2014 ◽  
Vol 58 (4) ◽  
pp. 2472-2474 ◽  
Author(s):  
Laurent Poirel ◽  
Encho Savov ◽  
Arzu Nazli ◽  
Angelina Trifonova ◽  
Iva Todorova ◽  
...  

ABSTRACTTwelve consecutive carbapenem-resistantEscherichia coliisolates were recovered from patients (infection or colonization) hospitalized between March and September 2012 in different units at a hospital in Bulgaria. They all produced the carbapenemase NDM-1 and the extended-spectrum-β-lactamase CTX-M-15, together with the 16S rRNA methylase RmtB, conferring high-level resistance to all aminoglycosides. All those isolates were clonally related and belonged to the same sequence type, ST101. In addition to being the first to identify NDM-producing isolates in Bulgaria, this is the very first study reporting an outbreak of NDM-1-producingE. coliin the world.


2013 ◽  
Vol 81 (4) ◽  
pp. 1078-1089 ◽  
Author(s):  
Yogitha N. Srikhanta ◽  
Dianna M. Hocking ◽  
Judyta Praszkier ◽  
Matthew J. Wakefield ◽  
Roy M. Robins-Browne ◽  
...  

ABSTRACTAraC-like regulators play a key role in the expression of virulence factors in enteric pathogens, such as enteropathogenicEscherichia coli(EPEC), enterotoxigenicE. coli, enteroaggregativeE. coli, andCitrobacter rodentium. Bioinformatic analysis of the genome of rabbit-specific EPEC (REPEC) strain E22 (O103:H2) revealed the presence of a gene encoding an AraC-like regulatory protein, RegR, which shares 71% identity to the global virulence regulator, RegA, ofC. rodentium. Microarray analysis demonstrated that RegR exerts 25- to 400-fold activation on transcription of several genes encoding putative virulence-associated factors, including a fimbrial operon (SEF14), a serine protease, and an autotransporter adhesin. These observations were confirmed by proteomic analysis of secreted and heat-extracted surface-associated proteins. The mechanism of RegR-mediated activation was investigated by using its most highly upregulated gene target,sefA. Transcriptional analyses and electrophoretic mobility shift assays showed that RegR activates the expression ofsefAby binding to a region upstream of thesefApromoter, thereby relieving gene silencing by the global regulatory protein H-NS. Moreover, RegR was found to contribute significantly to virulence in a rabbit infection experiment. Taken together, our findings indicate that RegR controls the expression of a series of accessory adhesins that significantly enhance the virulence of REPEC strain E22.


2014 ◽  
Vol 58 (6) ◽  
pp. 3538-3540 ◽  
Author(s):  
Tatsuya Tada ◽  
Tohru Miyoshi-Akiyama ◽  
Kayo Shimada ◽  
Teruo Kirikae

ABSTRACTNew Delhi metallo-β-lactamase-3 (NDM-3) was identified in a multidrug-resistantEscherichia coliisolate, NCGM77, obtained from the feces of a patient in Japan. The enzymatic activities of NDM-3 against β-lactams were similar to those of NDM-1, although NDM-3 showed slightly lowerkcat/Kmratios for all the β-lactams tested except for doripenem. The genetic context forblaNDM-3wastnpA-blaNDM-3-bleMBL-trpF-dsbC-tnpA-sulI-qacEdeltaI-aadA2-dfrA1, which was present on an approximately 250-kb plasmid.


2015 ◽  
Vol 59 (11) ◽  
pp. 7080-7083 ◽  
Author(s):  
Pedro Torres-González ◽  
Miriam Bobadilla-del Valle ◽  
Estrella Tovar-Calderón ◽  
Francisco Leal-Vega ◽  
Araceli Hernández-Cruz ◽  
...  

ABSTRACTCarbapenem-resistantEnterobacteriaceaecarrying New Delhi metallo-β-lactamase 1 (NDM-1) have rarely been reported in Latin America. We report of an outbreak caused by ablaNDM-1-harboring plasmid spread through different bacterial species, includingEscherichia coli(ST617) andEnterobacter cloacae(ST182) isolates from the same patient and threeKlebsiella pneumoniaeisolates (ST22) derived from three epidemiologically related patients. IncFII plasmids were found in all strains. Measures to control the outbreak were applied successfully.


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