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1

Detection of plasmid-mediated IMP-1 metallo-?-lactamase and quinolone resistance determinants in an ertapenem-resistant Enterobacter cloacae isolate  

UK PubMed Central (United Kingdom)

Objective: To investigate the mechanism of carbapenem resistance and the occurrence of plasmid-mediated quinolone resistance determinants qnr and aac(6′)-Ib-cr...Full Text Available

2009-05-01

2

New Plasmid-Mediated Fluoroquinolone Efflux Pump, QepA, Found in an Escherichia coli Clinical Isolate?  

UK PubMed Central (United Kingdom)

Plasmid-mediated Qnr and AAC(6′)-Ib-cr have been recognized as new molecular mechanisms affecting fluoroquinolone (FQ) resistance. C316, an Escherichia coli strain demonstrating...Full Text Available

2007-09-01

3

Complete Sequencing of pNDM-HK Encoding NDM-1 Carbapenemase from a Multidrug-Resistant Escherichia coli Strain Isolated in Hong Kong  

UK PubMed Central (United Kingdom)

BackgroundThe emergence of plasmid-mediated carbapenemases, such as NDM-1 in Enterobacteriaceae is a major public health issue. Since they mediate resistance to...Full Text Available

4

Transfer of Plasmid-Mediated CTX-M-9 from Salmonella enterica Serotype Virchow to Enterobacteriaceae in Human Flora-Associated Rats Treated with Cefixime?  

UK PubMed Central (United Kingdom)

Food animals are a potential source of CTX-M resistance genes for humans. We evaluated the transfer of the blaCTX-M-9 gene from an animal strain of Salmonella enterica...Full Text Available

2010-01-01

5

CTX-M-14, a Plasmid-Mediated CTX-M Type Extended-Spectrum ?-Lactamase Isolated from Escherichia coli  

UK PubMed Central (United Kingdom)

Four Escherichia coli isolates harboring CTX-M-14, with a single Ala231→Val substitution compared to CTX-M-9, had three different ribotypes. Cefotaxime resistance was plasmid...Full Text Available

2002-06-01

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Interaction of N-methyl-2-alkenyl-4-quinolones with ATP-dependent MurE ligase of Mycobacterium tuberculosis: antibacterial activity, molecular docking and inhibition kinetics  

UK PubMed Central (United Kingdom)

ObjectivesThe aim of this study was to comprehensively evaluate the antibacterial activity and MurE inhibition of a set of N-methyl-2-alkenyl-4-quinolones found...Full Text Available

2011-08-01

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R46 and pKM101 plasmid-mediated resistance to ionizing radiation in Escherichia coli  

International Nuclear Information System (INIS)

The ability of the R46 R factor and its derivative pKM101 to modify sensitivity to "6"0Co #gamma# radiation was studied. In Escherichia coli K12 both plasmids enhanced bacterial survival after "6"0Co #gamma# irradiation. This effect was dependent on recA"+ genotype but not on recB"+, recB"+recC"+, and recF"+ genotypes. 5-Fluorouracil eliminated the R46 R factor from the parent and its rec"- mutant strains. These strains lost not only the antibiotic resistance coded for R46 R factor but their radioresistance as well.

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Multiple-Dose Safety, Tolerability, and Pharmacokinetics of Oral Nemonoxacin (TG-873870) in Healthy Volunteers?  

UK PubMed Central (United Kingdom)

Nemonoxacin (TG-873870) is a novel nonfluorinated quinolone with broad-spectrum activities against Gram-positive and Gram-negative aerobic, anaerobic, and atypical pathogens, as well as against methicillin-resistant...Full Text Available

2010-01-01

9

Membrane Efflux and Influx Modulate both Multidrug Resistance and Virulence of Klebsiella pneumoniae in a Caenorhabditis elegans Model?  

UK PubMed Central (United Kingdom)

Cross-resistance to cefoxitin (FOX), chloramphenicol (CMP), and quinolones (nalidixic acid [NAL]) related to a putative efflux system overexpression has recently been reported for Klebsiella...Full Text Available

2010-10-01

10

Nature and distribution of mucosal lesions associated with enteropathogenic and enterohemorrhagic Escherichia coli in piglets and the role of plasmid-mediated factors.  

Science.gov (United States)

Bacterial attachment-effacement (att-eff) is emerging as an important virulence characteristic common to both enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). The contribution of the plasmid-encoded EPEC adherence factor to the production of mucosal lesions and diarrhea was investigated in gnotobiotic piglets. Bacterial att-aff in the intestinal mucosa of piglets infected with plasmid-cured EPEC strain E2348/69 (O127) was indistinguishable from that in piglets infected with the parent strain, but the distribution of lesions was different; it occurred in the small intestines of 6 of 7 piglets infected with the parent strain compared with only 2 of 11 (P = 0.006) infected with the plasmid-cured strain. Plasmid-encoded factors in EPEC and EHEC strains did not appear to contribute to bacterial competition with normal gut microflora. Of 13 strains belonging to five EPEC serogroups, O55, O142, O26, O119, and O111, 3 fulfilled the criteria for EHEC (2 O26 and 1 ...

1989-04-01

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Detection of 36 antibiotics in coastal waters using high performance liquid chromatography-tandem mass spectrometry  

British Library Electronic Table of Contents (United Kingdom)

Among pharmaceuticals and personal care products released into the aquatic environment, antibiotics are of particular concern, because of their ubiquity and health effects. Although scientists have recently paid more attention to the threat of antibiotics to coastal ecosystems, researchers have often focused on relatively few antibiotics, because of the absence of suitable analytical methods. We have therefore developed a method for the rapid detection of 36 antibiotic residues in coastal waters, including tetracyclines (TCs), sulfanilamides (SAs), and quinolones (QLs). The method consists of solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, using electrospray ionization (ESI) in positive mode. The SPE was performed with Oasis HLB and Oasi...

2011-01-01

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The neuroendocrine hormone norepinephrine increases Pseudomonas aeruginosa PA14 virulence through the las quorum-sensing pathway.  

Science.gov (United States)

It has been proposed that the gastrointestinal tract environment containing high levels of neuroendocrine hormones is important for gut-derived Pseudomonas aeruginosa infections. In this study, we report that the hormone norepinephrine increases P. aeruginosa PA14 growth, virulence factor production, invasion of HCT-8 epithelial cells, and swimming motility in a concentration-dependent manner. Transcriptome analysis of P. aeruginosa exposed to 500 microM, but not 50 microM, norepinephrine for 7 h showed that genes involved in the regulation of the virulence determinants pyocyanin, elastase, and the Pseudomonas quinolone signal (PQS, 2-heptyl-3-hydroxy-4-quinolone) were upregulated. The production of rhamnolipids, which are also important in P. aeruginosa infections, was not significantly altered in suspension cultures upon exposure to 500 microM norepinephrine but decreased on semisolid surfaces. Swarming motility, a phenotype that is directly ...

2009-06-11

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Developments of PET radioligands for NMDA receptors  

International Nuclear Information System (INIS)

Aim: There has been a great demand for developments of the radioligands to visualize the N-methyl-D-aspartate (NMDA) receptors by PET/SPECT. We have recently synthesized two C-11 labeled antagonists for the glycine-binding site on NMDA receptors. The aim of this work is to examine for their in vitro and in vivo binding characteristics, and to evaluate their potentials as PET radioligands for the NMDA receptors. Materials and methods: Two C-11 labeled 4-hydroxy-2-quinolones (1 and 2) were synthesized by conventional methylation of the corresponding phenols with ["1"1C]methyl iodide. In vitro and ex vivo quantitative autoradiographs with imaging plate, as well as animal PET, were employed in order to evaluate their in vitro and in vivo binding to the NMDA receptors. Results: The compound 1 showed the specific binding to rat brain slices with higher localization in the hippocampus and cerebral cortex than in the cerebellum. Both glycine antagonists and agonists ...

2002-09-01

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Transcriptional Profiling Analysis of the Global Regulator NorG, a GntR-Like Protein of Staphylococcus aureus.  

Science.gov (United States)

The GntR-like protein NorG has been shown to affect Staphylococcus aureus genes involved in the resistance to quinolones and ?-lactams, such as those encoding the NorB and AbcA transporters. To identify the target genes regulated by NorG, we carried out transcriptional profiling assays using S. aureus RN6390 and its isogenic norG::cat mutant. Our data showed that NorG positively affected the transcription of global regulators mgrA, arlS, and sarZ. The three putative drug efflux pump genes most positively affected by NorG were the NorB efflux pump (5.1-fold), the MmpL-like protein SACOL2566 (5.2-fold), and the BcrA-like drug transporter SACOL2525 (5.7-fold). The S. aureus predicted MmpL protein showed 53% homology with the MmpL lipid transporter of Mycobacterium tuberculosis, and the putative SACOL2525 protein showed 87% homology with the bacitracin drug transporter BcrA of Staphylococcus hominis. Two pump genes most negatively affected by NorG were NorC (4-fold) ...

2011-09-01