scholarly journals New Sequence Types and Multidrug Resistance among Pathogenic Escherichia coli Isolates from Coastal Marine Sediments

2012 ◽  
Vol 78 (11) ◽  
pp. 3916-3922 ◽  
Author(s):  
C. Vignaroli ◽  
G. M. Luna ◽  
C. Rinaldi ◽  
A. Di Cesare ◽  
R. Danovaro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Marine Sediments ◽  
Resistance Genes ◽  
Class 1 Integron ◽  
Coastal Marine Sediments ◽  
Content Type ◽  
Coastal Marine ◽  
Class 1 ◽  
Coastal Marine Sediment ◽  
Multiresistant Strains

ABSTRACTThe spread of antibiotic-resistant microorganisms is widely recognized, but data about their sources, presence, and significance in marine environments are still limited. We examined 109Escherichia colistrains from coastal marine sediments carrying virulence genes for antibiotic susceptibility, specific resistance genes, prevalence of class 1 and 2 integrons, and sequence type. Antibiotic resistance was found in 35% of strains, and multiple resistances were found in 14%; the resistances detected most frequently were against tetracycline (28%), ampicillin (16.5%), trimethoprim-sulfamethoxazole (13%), and streptomycin (7%). The highest prevalence of resistant strains was in phylogenetic group A, whereas phylogroup B2 exhibited a significantly lower frequency than all the other groups. Sixty percent of multiresistant strains harbored class 1 or 2 integrase genes, and about 50% carried resistance genes (particularlydfrAandaadA) linked to a class 1 integron. Multilocus sequence typing of 14 selected strains identified eight different types characteristic of extraintestinal pathogens and three new allelic combinations. Our data suggest that coastal marine sediment may be a suitable environment for the survival of pathogenic and antimicrobial-resistantE. colistrains capable of contributing to resistance spread via integrons among benthic bacteria, and they highlight a role for these strains in the emergence of new virulent genotypes.

scholarly journals First IncHI2 Plasmid Carrying mcr-9.1 , bla VIM-1 , and Double Copies of bla KPC-3 in a Multidrug-Resistant Escherichia coli Human Isolate

mSphere ◽  
2021 ◽  
Author(s):  
Serena Simoni ◽  
Marina Mingoia ◽  
Andrea Brenciani ◽  
Maria Carelli ◽  
Maria M. Lleò ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Multidrug Resistant ◽  
Human Isolate ◽  
Colistin Resistance ◽  
Class 1 Integron ◽  
Content Type ◽  
Single Plasmid ◽  
Class 1

We report a novel IncHI2 plasmid coharboring bla VIM-1 , two copies of bla KPC-3 and mcr-9.1 resistance genes in a human Escherichia coli of the new serogroup O188. The bla VIM-1 gene was included in a class 1 integron, mcr-9.1 in a cassette bracketed by IS 903 and ΔIS1R, and bla KPC-3 in two copies within a new composite Tn 4401 -like transposon. The emergence of carbapenem and colistin resistance genes in a single plasmid is of great concern for upcoming clinical therapies.

scholarly journals Genomic Insights into Two Novel Fe(II)-Oxidizing Zetaproteobacteria Isolates Reveal Lifestyle Adaption to Coastal Marine Sediments

2020 ◽  
Vol 86 (17) ◽  
Author(s):  
Nia Blackwell ◽  
Casey Bryce ◽  
Daniel Straub ◽  
Andreas Kappler ◽  
Sara Kleindienst
Keyword(s):  
Oxidative Stress ◽  
Marine Sediments ◽  
Hydrothermal Vents ◽  
Sequence Similarity ◽  
Molecular Techniques ◽  
Rrna Gene ◽  
Coastal Marine Sediments ◽  
Content Type ◽  
Coastal Marine ◽  
Stress Related Genes

ABSTRACT The discovery of the novel Zetaproteobacteria class greatly expanded our understanding of neutrophilic, microaerophilic microbial Fe(II) oxidation in marine environments. Despite molecular techniques demonstrating their global distribution, relatively few isolates exist, especially from low-Fe(II) environments. Furthermore, the Fe(II) oxidation pathways used by Zetaproteobacteria remain poorly understood. Here, we present the genomes (>99% genome completeness) of two Zetaproteobacteria, which are the only cultivated isolates originating from typical low-Fe [porewater Fe(II), 70 to 100 μM] coastal marine sediments. The two strains share <90% average nucleotide identity (ANI) with each other and <80% ANI with any other Zetaproteobacteria genome. The closest relatives were Mariprofundus aestuarium strain CP-5 and Mariprofundus ferrinatatus strain CP-8 (96 to 98% 16S rRNA gene sequence similarity). Fe(II) oxidation of strains KV and NF is most likely mediated by the putative Fe(II) oxidase Cyc2. Interestingly, the genome of strain KV also encodes a putative multicopper oxidase, PcoAB, which could play a role in Fe(II) oxidation, a pathway found only in two other Zetaproteobacteria genomes (Ghiorsea bivora TAG-1 and SCGC AB-602-C20). The strains show potential adaptations to fluctuating O2 concentrations, indicated by the presence of both cbb3- and aa3-type cytochrome c oxidases, which are adapted to low and high O2 concentrations, respectively. This is further supported by the presence of several oxidative-stress-related genes. In summary, our results reveal the potential Fe(II) oxidation pathways employed by these two novel chemolithoautotrophic Fe(II)-oxidizing species and the lifestyle adaptations which enable the Zetaproteobacteria to survive in coastal environments with low Fe(II) and regular redox fluctuations. IMPORTANCE Until recently, the importance and relevance of Zetaproteobacteria were mainly thought to be restricted to high-Fe(II) environments, such as deep-sea hydrothermal vents. The two novel Mariprofundus isolates presented here originate from typical low-Fe(II) coastal marine sediments. As well as being low in Fe(II), these environments are often subjected to fluctuating O2 concentrations and regular mixing by wave action and bioturbation. The discovery of two novel isolates highlights the importance of these organisms in such environments, as Fe(II) oxidation has been shown to impact nutrients and trace metals. Genome analysis of these two strains further supported their lifestyle adaptation and therefore their potential preference for coastal marine sediments, as genes necessary for surviving dynamic O2 concentrations and oxidative stress were identified. Furthermore, our analyses also expand our understanding of the poorly understood Fe(II) oxidation pathways used by neutrophilic, microaerophilic Fe(II) oxidizers.

scholarly journals Identification and Molecular Characterization of Class 1 Integrons in Multiresistant Escherichia coli Isolates from Poultry Litter

2012 ◽  
Vol 78 (15) ◽  
pp. 5444-5447 ◽  
Author(s):  
Elizabeth Ponce-Rivas ◽  
María-Enriqueta Muñoz-Márquez ◽  
Ashraf A. Khan
Keyword(s):  
Escherichia Coli ◽  
Poultry Litter ◽  
Class 1 Integron ◽  
Content Type ◽  
Gene Cassettes ◽  
E Coli ◽  
Class 1 ◽  
Chicken Litter ◽  
Diverse Origin

ABSTRACTThis study describes the prevalence of arrays of class 1 integron cassettes and Qnr determinants (A, B, and S) in 19 fluoroquinolone-resistantEscherichia coliisolates from chicken litter.qnrSandqnrAwere the predominant genes in these fluoroquinolone-resistant isolates, and an uncommon array ofaacA4-catB3-dfrA1gene cassettes from a class1 integron was found. Additionally,aadA1anddfrA1gene cassettes, encoding resistance to streptomycin and trimethoprim, constituted the most common genes identified and was located on megaplasmids as well on the chromosome. Antibiotic resistance, pulsed-field gel electrophoresis (PFGE), and plasmid data suggest a genetically diverse origin of poultryE. coliisolates.

scholarly journals Microaerophilic Fe(II)-Oxidizing Zetaproteobacteria Isolated from Low-Fe Marine Coastal Sediments: Physiology and Composition of Their Twisted Stalks

2017 ◽  
Vol 83 (8) ◽  
Author(s):  
K. Laufer ◽  
M. Nordhoff ◽  
M. Halama ◽  
R. E. Martinez ◽  
M. Obst ◽  
...  
Keyword(s):  
Trace Metals ◽  
Marine Sediments ◽  
Dry Weight ◽  
Coastal Sediments ◽  
Organic Carbon Content ◽  
Coastal Marine Sediments ◽  
Content Type ◽  
Marine Habitats ◽  
Coastal Marine ◽  
Freshwater Habitats

ABSTRACT Microaerophilic Fe(II) oxidizers are commonly found in habitats containing elevated Fe(II) and low O2 concentrations and often produce characteristic Fe mineral structures, so-called twisted stalks or tubular sheaths. Isolates originating from freshwater habitats are all members of the Betaproteobacteria, while isolates from marine habitats belong almost exclusively to the Zetaproteobacteria. So far, only a few isolates of marine microaerophilic Fe(II) oxidizers have been described, all of which are obligate microaerophilic Fe(II) oxidizers and have been thought to be restricted to Fe-rich systems. Here, we present two new isolates of marine microaerophilic Fe(II)-oxidizing Zetaproteobacteria that originate from typical coastal marine sediments containing only low Fe concentrations (2 to 11 mg of total Fe/g of sediment [dry weight]; 70 to 100 μM dissolved Fe2+ in the porewater). The two novel Zetaproteobacteria share characteristic physiological properties of the Zetaproteobacteria group, even though they come from low-Fe environments: the isolates are obligate microaerophilic Fe(II) oxidizers and, like most isolated Zetaproteobacteria, they produce twisted stalks. We found a low organic carbon content in the stalks (∼0.3 wt%), with mostly polysaccharides and saturated aliphatic chains (most likely lipids). The Fe minerals in the stalks were identified as lepidocrocite and possibly ferrihydrite. Immobilization experiments with Ni2+ showed that the stalks can function as a sink for trace metals. Our findings show that obligate microaerophilic Fe(II) oxidizers belonging to the Zetaproteobacteria group are not restricted to Fe-rich environments but can also be found in low-Fe marine environments, which increases their overall importance for the global biogeochemical Fe cycle. IMPORTANCE So far, only a few isolates of benthic marine microaerophilic Fe(II) oxidizers belonging to the Zetaproteobacteria exist, and most isolates were obtained from habitats containing elevated Fe concentrations. Consequently, it was thought that these microorganisms are important mainly in habitats with high Fe concentrations. The two novel isolates of Zetaproteobacteria that are presented in the present study were isolated from typical coastal marine sediments that do not contain elevated Fe concentrations. This increases the knowledge about possible habitats in which Zetaproteobacteria can exist. Furthermore, we show that the physiology and the typical organo-mineral structures (twisted stalks) that are produced by the isolates do not notably differ from the physiology and the cell-mineral structures of isolates from environments with high Fe concentrations. We also showed that the organo-mineral structures can function as a sink for trace metals.

scholarly journals Novel 6′-N-Aminoglycoside Acetyltransferase AAC(6′)-Iaj from a Clinical Isolate of Pseudomonas aeruginosa

2012 ◽  
Vol 57 (1) ◽  
pp. 96-100 ◽  
Author(s):  
Tatsuya Tada ◽  
Tohru Miyoshi-Akiyama ◽  
Kayo Shimada ◽  
Masahiro Shimojima ◽  
Teruo Kirikae
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Acquired Resistance ◽  
Amino Groups ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Content Type ◽  
Class 1 ◽  
Layer Chromatography

ABSTRACTPseudomonas aeruginosaNCGM1588 has a novel chromosomal class 1 integron, In151, which includes theaac(6′)-Iajgene. The encoded protein, AAC(6′)-Iaj, was found to consist of 184 amino acids, with 70% identity to AAC(6′)-Ia.Escherichia colitransformed with a plasmid containing theaac(6′)-Iajgene acquired resistance to all aminoglycosides tested except gentamicin. Of note,aac(6′)-Iajcontributed to the resistance to arbekacin. Thin-layer chromatography revealed that AAC(6′)-Iaj acetylated all aminoglycosides tested except gentamicin. These findings indicated that AAC(6′)-Iaj is a functional acetyltransferase that modifies the amino groups at the 6′ positions of aminoglycosides and contributes to aminoglycoside resistance ofP. aeruginosaNCGM1588, including arbekacin.

scholarly journals First Report ofblaIMP-14on a Plasmid Harboring Multiple Drug Resistance Genes in Escherichia coli Sequence Type 131

2016 ◽  
Vol 60 (8) ◽  
pp. 5068-5071 ◽  
Author(s):  
Nicole Stoesser ◽  
Anna E. Sheppard ◽  
Gisele Peirano ◽  
Robert P. Sebra ◽  
Tarah Lynch ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Multiple Drug Resistance ◽  
Carbapenem Resistance ◽  
Sequence Type ◽  
Multiple Drug ◽  
Class 1 Integron ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Class 1

ABSTRACTTheblaIMP-14carbapenem resistance gene has largely previously been observed inPseudomonas aeruginosaandAcinetobacterspp. As part of global surveillance and sequencing of carbapenem-resistantEscherichia coli, we identified a sequence type 131 strain harboringblaIMP-14within a class 1 integron, itself nested within an ∼54-kb multidrug resistance region on an epidemic IncA/C2plasmid. The emergence ofblaIMP-14in this context in the ST131 lineage is of potential clinical concern.

scholarly journals Emergence of Escherichia coli Sequence Type ST131 Carrying both theblaGES-5andblaCTX-M-15Genes

2011 ◽  
Vol 55 (6) ◽  
pp. 2974-2975 ◽  
Author(s):  
Juwon Kim ◽  
Seong Geun Hong ◽  
Il Kwon Bae ◽  
Ji Roung Kang ◽  
Seok Hoon Jeong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolate ◽  
Sequence Type ◽  
Class 1 Integron ◽  
Content Type ◽  
Class 1 ◽  
High Level ◽  
Level Resistance

ABSTRACTEscherichia coliclinical isolate BD07372 of sequence type ST131 recovered from a bed sore specimen exhibited high-level resistance to ceftazidime and cefotaxime but exhibited susceptibility to imipenem and meropenem. The isolate harbored two β-lactamase genes, theblaCTX-M-15gene carried by an ∼250-kbp plasmid carrying the FIA and FIC replicons and theblaGES-5gene carried by a class 1 integron in the chromosome.

scholarly journals Engineering a CRISPR Interference System To Repress a Class 1 Integron in Escherichia coli

2019 ◽  
Vol 64 (3) ◽  
Author(s):  
Qingyang Li ◽  
Peng Zhao ◽  
Lili Li ◽  
Haifeng Zhao ◽  
Lei Shi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Cellular Therapy ◽  
Antibiotic Resistance Genes ◽  
Transcriptional Level ◽  
Class 1 Integron ◽  
Content Type ◽  
E Coli ◽  
Crispr Interference ◽  
Class 1

ABSTRACT Microbial multidrug resistance (MDR) poses a huge threat to human health. Bacterial acquisition of MDR relies primarily on class 1 integron-involved horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). To date, no strategies other than the use of antibiotics can efficiently cope with MDR. Here, we report that an engineered CRISPR interference (CRISPRi) system can markedly reduce MDR by blocking a class 1 integron in Escherichia coli. Using CRISPRi to block plasmid R388 class 1 integron, E. coli recombinants showed halted growth upon exposure to relevant antibiotics. A microplate alamarBlue assay showed that both subgenomic RNAs (sgRNAs) R3 and R6 led to 8- and 32-fold decreases in half-maximal inhibitory concentrations (IC50) for trimethoprim and sulfamethoxazole, respectively. Reverse transcription and quantitative PCR (RT-qPCR) revealed that the strain employing sgRNA R6 exhibited 97% and 84% decreases in the transcriptional levels of the dfrB2 cassette and sul1, two typical ARGs, respectively. RT-qPCR analysis also demonstrated that the strain recruiting sgRNA R3 showed a 96% decrease in the transcriptional level of intI1, and a conjugation assay revealed a 1,000-fold decrease in HGT rates of ARGs. Overall, the sgRNA R3 targeting the 31 bp downstream of the Pc promoter on the intI1 nontemplate strand outperformed other sgRNAs in reducing integron activity. Furthermore, this CRISPRi system is reversible, genetically stable, and titratable by varying the concentration of the inducer. To our knowledge, this is the first report on exploiting a CRISPRi system to reduce the class 1 integron in E. coli. This study provides valuable insights for future development of CRISPRi-based antimicrobial agents and cellular therapy to suppress MDR.

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