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  1 / 1593 MEDLINE  
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[PMID]:28911105
[Au] Autor:Taylor JA; Panis G; Viollier PH; Marczynski GT
[Ad] Endereço:Department of Microbiology and Immunology, McGill University, 3775 University St., Montreal, QC H3A 2B4, Canada.
[Ti] Título:A novel nucleoid-associated protein coordinates chromosome replication and chromosome partition.
[So] Source:Nucleic Acids Res;45(15):8916-8929, 2017 Sep 06.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We searched for regulators of chromosome replication in the cell cycle model Caulobacter crescentus and found a novel DNA-binding protein (GapR) that selectively aids the initiation of chromosome replication and the initial steps of chromosome partitioning. The protein binds the chromosome origin of replication (Cori) and has higher-affinity binding to mutated Cori-DNA that increases Cori-plasmid replication in vivo. gapR gene expression is essential for normal rapid growth and sufficient GapR levels are required for the correct timing of chromosome replication. Whole genome ChIP-seq identified dynamic DNA-binding distributions for GapR, with the strongest associations at the partitioning (parABS) locus near Cori. Using molecular-genetic and fluorescence microscopy experiments, we showed that GapR also promotes the first steps of chromosome partitioning, the initial separation of the duplicated parS loci following replication from Cori. This separation occurs before the parABS-dependent partitioning phase. Therefore, this early separation, whose mechanisms is not known, coincides with the poorly defined mechanism(s) that establishes chromosome asymmetry: C. crescentus chromosomes are partitioned to distinct cell-poles which develop into replicating and non-replicating cell-types. We propose that GapR coordinates chromosome replication with asymmetry-establishing chromosome separation, noting that both roles are consistent with the phylogenetic restriction of GapR to asymmetrically dividing bacteria.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
Caulobacter crescentus/genética
Segregação de Cromossomos
Cromossomos Bacterianos/metabolismo
Replicação do DNA
Proteínas de Ligação a DNA/genética
[Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo
Caulobacter crescentus/efeitos dos fármacos
Caulobacter crescentus/metabolismo
Divisão Celular/efeitos dos fármacos
Cromossomos Bacterianos/ultraestrutura
Proteínas de Ligação a DNA/metabolismo
Regulação Bacteriana da Expressão Gênica
Mutação
Novobiocina/farmacologia
Plasmídeos/química
Plasmídeos/metabolismo
Origem de Replicação
Rifampina/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA-Binding Proteins); 17EC19951N (Novobiocin); VJT6J7R4TR (Rifampin)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170916
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx596


  2 / 1593 MEDLINE  
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[PMID]:28650638
[Au] Autor:Haynes KM; Abdali N; Jhawar V; Zgurskaya HI; Parks JM; Green AT; Baudry J; Rybenkov VV; Smith JC; Walker JK
[Ad] Endereço:Department of Pharmacological & Physiological Science, Saint Louis University School of Medicine , St Louis, Missouri 63104, United States.
[Ti] Título:Identification and Structure-Activity Relationships of Novel Compounds that Potentiate the Activities of Antibiotics in Escherichia coli.
[So] Source:J Med Chem;60(14):6205-6219, 2017 Jul 27.
[Is] ISSN:1520-4804
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In Gram-negative bacteria, efflux pumps are able to prevent effective cellular concentrations from being achieved for a number of antibiotics. Small molecule adjuvants that act as efflux pump inhibitors (EPIs) have the potential to reinvigorate existing antibiotics that are currently ineffective due to efflux mechanisms. Through a combination of rigorous experimental screening and in silico virtual screening, we recently identified novel classes of EPIs that interact with the membrane fusion protein AcrA, a critical component of the AcrAB-TolC efflux pump in Escherichia coli. Herein, we present initial optimization efforts and structure-activity relationships around one of those previously described hits, NSC 60339 (1). From these efforts we identified two compounds, SLUPP-225 (17h) and SLUPP-417 (17o), which demonstrate favorable properties as potential EPIs in E. coli cells including the ability to penetrate the outer membrane, improved inhibition of efflux relative to 1, and potentiation of the activity of novobiocin and erythromycin.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Proteínas de Transporte/metabolismo
Cinamatos/química
Proteínas de Escherichia coli/metabolismo
Escherichia coli/efeitos dos fármacos
Imidazóis/química
Lipoproteínas/metabolismo
Proteínas de Membrana Transportadoras/metabolismo
[Mh] Termos MeSH secundário: Permeabilidade da Membrana Celular
Cinamatos/síntese química
Cinamatos/farmacologia
Simulação por Computador
Bases de Dados de Compostos Químicos
Farmacorresistência Bacteriana/efeitos dos fármacos
Sinergismo Farmacológico
Eritromicina/farmacologia
Escherichia coli/metabolismo
Imidazóis/síntese química
Imidazóis/farmacologia
Testes de Sensibilidade Microbiana
Modelos Moleculares
Novobiocina/farmacologia
Ligação Proteica
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (AcrA protein, E coli); 0 (AcrAB-TolC protein, E coli); 0 (Anti-Bacterial Agents); 0 (Carrier Proteins); 0 (Cinnamates); 0 (Escherichia coli Proteins); 0 (Imidazoles); 0 (Lipoproteins); 0 (Membrane Transport Proteins); 0 (SLUPP-225); 0 (SLUPP-417); 17EC19951N (Novobiocin); 63937KV33D (Erythromycin)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170627
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jmedchem.7b00453


  3 / 1593 MEDLINE  
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[PMID]:28355308
[Au] Autor:Araya-Cloutier C; Martens B; Schaftenaar G; Leipoldt F; Gruppen H; Vincken JP
[Ad] Endereço:Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands.
[Ti] Título:Structural basis for non-genuine phenolic acceptor substrate specificity of Streptomyces roseochromogenes prenyltransferase CloQ from the ABBA/PT-barrel superfamily.
[So] Source:PLoS One;12(3):e0174665, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Acceptor substrate specificity of Streptomyces roseochromogenes prenyltransferase SrCloQ was investigated using different non-genuine phenolic compounds. RP-UHPLC-UV-MSn was used for the tentative annotation and quantification of the prenylated products. Flavonoids, isoflavonoids and stilbenoids with different types of substitution were prenylated by SrCloQ, although with less efficiency than the genuine substrate 4-hydroxyphenylpyruvate. The isoflavan equol, followed by the flavone 7,4'-dihydroxyflavone, were the best non-genuine acceptor substrates. B-ring C-prenylation was in general preferred over A-ring C-prenylation (ratio 5:1). Docking studies of non-genuine acceptor substrates with the B-ring oriented towards the donor substrate dimethylallyl pyrophosphate, showed that the carbonyl group of the C-ring was able to make stabilizing interactions with the residue Arg160, which might determine the preference observed for B-ring prenylation. No reaction products were formed when the acceptor substrate had no phenolic hydroxyl groups. This preference can be explained by the essential hydrogen bond needed between a phenolic hydroxyl group and the residue Glu281. Acceptor substrates with an additional hydroxyl group at the C3' position (B-ring), were mainly O3'-prenylated (> 80% of the reaction products). This can be explained by the proximity of the C3' hydroxyl group to the donor substrate at the catalytic site. Flavones were preferred over isoflavones by SrCloQ. Docking studies suggested that the orientation of the B-ring and of the phenolic hydroxyl group at position C7 (A-ring) of flavones towards the residue Tyr233 plays an important role in this observed preference. Finally, the insights obtained on acceptor substrate specificity and regioselectivity for SrCloQ were extended to other prenyltransferases from the CloQ/NhpB family.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Dimetilaliltranstransferase/metabolismo
Flavonoides/metabolismo
Isoflavonas/metabolismo
Streptomyces/enzimologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/química
Domínio Catalítico
Dimetilaliltranstransferase/química
Equol/química
Equol/metabolismo
Flavonoides/química
Ligações de Hidrogênio
Isoflavonas/química
Cinética
Simulação de Acoplamento Molecular
Estrutura Molecular
Novobiocina/análogos & derivados
Novobiocina/biossíntese
Novobiocina/química
Fenóis/química
Fenóis/metabolismo
Ácidos Fenilpirúvicos/química
Ácidos Fenilpirúvicos/metabolismo
Prenilação
Ligação Proteica
Estrutura Terciária de Proteína
Estilbenos/química
Estilbenos/metabolismo
Streptomyces/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Flavonoids); 0 (Isoflavones); 0 (Phenols); 0 (Phenylpyruvic Acids); 0 (Stilbenes); 156-39-8 (4-hydroxyphenylpyruvic acid); 17EC19951N (Novobiocin); 39868-96-7 (clorobiocin); 531-95-3 (Equol); EC 2.5.1.1 (Dimethylallyltranstransferase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170330
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0174665


  4 / 1593 MEDLINE  
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[PMID]:28068060
[Au] Autor:Sadler JC; Chung CH; Mosley JE; Burley GA; Humphreys LD
[Ad] Endereço:GlaxoSmithKline Medicines Research Centre , Gunnels Wood Road, Stevenage, SG1 2NY , United Kingdom.
[Ti] Título:Structural and Functional Basis of C-Methylation of Coumarin Scaffolds by NovO.
[So] Source:ACS Chem Biol;12(2):374-379, 2017 Feb 17.
[Is] ISSN:1554-8937
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:C-methylation of aromatic small molecules by C-methyltransferases (C-MTs) is an important biological transformation that involves C-C bond formation using S-adenosyl-l-methionine (SAM) as the methyl donor. Here, two advances in the mechanistic understanding of C-methylation of the 8-position of coumarin substrates catalyzed by the C-MT NovO from Streptomyces spheroides are described. First, a crystal structure of NovO reveals the Arg116-Asn117 and His120-Arg121 motifs are essential for coumarin substrate binding. Second, the active-site His120 is responsible for deprotonation of the phenolic 7-hydroxyl group on the coumarin substrate, activating the rate-determining methyl transfer step from SAM. This work expands our mechanistic knowledge of C-MTs, which could be used in the downstream development of engineered biocatalysts for small molecule C-alkylations.
[Mh] Termos MeSH primário: Cumarínicos/metabolismo
[Mh] Termos MeSH secundário: Catálise
Cristalografia por Raios X
Metilação
Metiltransferases/metabolismo
Estrutura Molecular
Novobiocina/biossíntese
Novobiocina/química
Streptomyces/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Coumarins); 17EC19951N (Novobiocin); A4VZ22K1WT (coumarin); EC 2.1.1.- (Methyltransferases)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170713
[Lr] Data última revisão:
170713
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170110
[St] Status:MEDLINE
[do] DOI:10.1021/acschembio.6b01053


  5 / 1593 MEDLINE  
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[PMID]:28019693
[Au] Autor:Scanlan E; Ardill L; Whelan MV; Shortt C; Nally JE; Bourke B; Ó Cróinín T
[Ad] Endereço:School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
[Ti] Título:Relaxation of DNA supercoiling leads to increased invasion of epithelial cells and protein secretion by Campylobacter jejuni.
[So] Source:Mol Microbiol;104(1):92-104, 2017 04.
[Is] ISSN:1365-2958
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Invasion of intestinal epithelial cells by Campylobacter jejuni is a critical step during infection of the intestine by this important human pathogen. In this study we investigated the role played by DNA supercoiling in the regulation of invasion of epithelial cells and the mechanism by which this could be mediated. A significant correlation between more relaxed DNA supercoiling and an increased ability of C. jejuni strains to penetrate human epithelial cells was demonstrated. Directly inducing relaxation of DNA supercoiling in C. jejuni was shown to significantly increase invasion of epithelial cells. Mutants in the fibronectin binding proteins CadF and FlpA still displayed an increased invasion after treatment with novobiocin suggesting these proteins were not essential for the observed phenotype. However, a large increase in protein secretion from multiple C. jejuni strains upon relaxation of DNA supercoiling was demonstrated. This increase in protein secretion was not mediated by outer membrane vesicles and appeared to be dependent on an intact flagellar structure. This study identifies relaxation of DNA supercoiling as playing a key role in enhancing C. jejuni pathogenesis during infection of the human intestine and identifies proteins present in a specific invasion associated secretome induced by relaxation of DNA supercoiling.
[Mh] Termos MeSH primário: Campylobacter jejuni/metabolismo
DNA Super-Helicoidal/genética
DNA Super-Helicoidal/metabolismo
[Mh] Termos MeSH secundário: Aderência Bacteriana/fisiologia
Proteínas da Membrana Bacteriana Externa/genética
Proteínas da Membrana Bacteriana Externa/metabolismo
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Infecções por Campylobacter/metabolismo
Infecções por Campylobacter/microbiologia
Campylobacter jejuni/genética
Proteínas de Transporte/genética
Proteínas de Transporte/metabolismo
Linhagem Celular
Movimento Celular/genética
DNA/metabolismo
Células Epiteliais/microbiologia
Fibronectinas/metabolismo
Seres Humanos
Intestinos/metabolismo
Novobiocina/metabolismo
Sistemas de Translocação de Proteínas
Transporte Proteico
Fatores de Transcrição/genética
Fatores de Transcrição/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Outer Membrane Proteins); 0 (Bacterial Proteins); 0 (CadF protein, Campylobacter jejuni); 0 (Carrier Proteins); 0 (DNA, Superhelical); 0 (Fibronectins); 0 (FlpA protein, bacteria); 0 (Protein Translocation Systems); 0 (Transcription Factors); 17EC19951N (Novobiocin); 9007-49-2 (DNA)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161227
[St] Status:MEDLINE
[do] DOI:10.1111/mmi.13614


  6 / 1593 MEDLINE  
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[PMID]:28019639
[Au] Autor:Dlugosz A; Janecka A
[Ad] Endereço:Department of Biomolecular Chemistry, Medical University of Lodz, Lodz, Poland.
[Ti] Título:Novobiocin Analogs as Potential Anticancer Agents.
[So] Source:Mini Rev Med Chem;17(9):728-733, 2017.
[Is] ISSN:1875-5607
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The aminocoumarin antibiotic, novobiocin, is a natural product that inhibits DNA gyrase, a bacterial enzyme involved in cell division. METHOD: More recently, novobiocin was found to act also on eukaryotic cells by blocking the 90 kDa heat shock protein (Hsp90). Hsp90 is a molecular chaperone, critical for folding, stabilization and activation of many proteins, in particular oncoproteins responsible for cancer progression. As opposed to the geldanamycin and radicicol, the known inhibitors of Hsp90 that bind to the N-terminal region, the binding domain of novobiocin is localized in the C-terminal part of this protein. While the N-terminal inhibition also leads to the induction of some pro-survival signals, C-terminal inhibitors in which prosurvival responses are avoided and client degradation is maintained can be developed as a new class of potential anticancer chemotherapeutics. Numerous novobiocin analogs have been designed in the search for more potent compounds and some of them exhibit significantly enhanced anti-proliferative activity versus the natural product, as evaluated by cellular efficacies against several cancer cell lines. CONCLUSION: This review describes structure-activity-relationships of novobiocin analogs and some biological data reported so far on the anticancer activity of these modified compounds.
[Mh] Termos MeSH primário: Antineoplásicos/farmacologia
Novobiocina/farmacologia
[Mh] Termos MeSH secundário: Antineoplásicos/síntese química
Antineoplásicos/química
Proliferação Celular/efeitos dos fármacos
Proteínas de Choque Térmico HSP90/antagonistas & inibidores
Seres Humanos
Novobiocina/síntese química
Novobiocina/química
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Antineoplastic Agents); 0 (HSP90 Heat-Shock Proteins); 17EC19951N (Novobiocin)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161227
[St] Status:MEDLINE
[do] DOI:10.2174/1389557516666161223155525


  7 / 1593 MEDLINE  
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[PMID]:27941026
[Au] Autor:Kasho K; Tanaka H; Sakai R; Katayama T
[Ad] Endereço:From the Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
[Ti] Título:Cooperative DnaA Binding to the Negatively Supercoiled datA Locus Stimulates DnaA-ATP Hydrolysis.
[So] Source:J Biol Chem;292(4):1251-1266, 2017 Jan 27.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Timely initiation of replication in Escherichia coli requires functional regulation of the replication initiator, ATP-DnaA. The cellular level of ATP-DnaA increases just before initiation, after which its level decreases through hydrolysis of DnaA-bound ATP, yielding initiation-inactive ADP-DnaA. Previously, we reported a novel DnaA-ATP hydrolysis system involving the chromosomal locus datA and named it datA-dependent DnaA-ATP hydrolysis (DDAH). The datA locus contains a binding site for a nucleoid-associating factor integration host factor (IHF) and a cluster of three known DnaA-binding sites, which are important for DDAH. However, the mechanisms underlying the formation and regulation of the datA-IHF·DnaA complex remain unclear. We now demonstrate that a novel DnaA box within datA is essential for ATP-DnaA complex formation and DnaA-ATP hydrolysis. Specific DnaA residues, which are important for interaction with bound ATP and for head-to-tail inter-DnaA interaction, were also required for ATP-DnaA-specific oligomer formation on datA Furthermore, we show that negative DNA supercoiling of datA stabilizes ATP-DnaA oligomers, and stimulates datA-IHF interaction and DnaA-ATP hydrolysis. Relaxation of DNA supercoiling by the addition of novobiocin, a DNA gyrase inhibitor, inhibits datA function in cells. On the basis of these results, we propose a mechanistic model of datA-IHF·DnaA complex formation and DNA supercoiling-dependent regulation for DDAH.
[Mh] Termos MeSH primário: Trifosfato de Adenosina/metabolismo
Proteínas de Bactérias/metabolismo
DNA Bacteriano/metabolismo
DNA Super-Helicoidal/metabolismo
Proteínas de Ligação a DNA/metabolismo
Escherichia coli/metabolismo
Loci Gênicos/fisiologia
[Mh] Termos MeSH secundário: Trifosfato de Adenosina/genética
Proteínas de Bactérias/genética
DNA Girase/genética
DNA Girase/metabolismo
DNA Bacteriano/genética
DNA Super-Helicoidal/genética
Proteínas de Ligação a DNA/genética
Escherichia coli/genética
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Hidrólise
Fatores Hospedeiros de Integração/genética
Fatores Hospedeiros de Integração/metabolismo
Novobiocina/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA, Bacterial); 0 (DNA, Superhelical); 0 (DNA-Binding Proteins); 0 (DnaA protein, Bacteria); 0 (Escherichia coli Proteins); 0 (Integration Host Factors); 0 (integration host factor, E coli); 17EC19951N (Novobiocin); 8L70Q75FXE (Adenosine Triphosphate); EC 5.99.1.3 (DNA Gyrase)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170605
[Lr] Data última revisão:
170605
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161213
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M116.762815


  8 / 1593 MEDLINE  
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[PMID]:27815129
[Au] Autor:Lahmar A; Bedoui A; Mokdad-Bzeouich I; Dhaouifi Z; Kalboussi Z; Cheraif I; Ghedira K; Chekir-Ghedira L
[Ad] Endereço:Laboratoire de Biologie Cellulaire et Moléculaire, Faculté de Médecine Dentaire, Université de Monastir, Rue Avicenne, Monastir, Tunisia; Unité de Substances Naturelles Bioactives et Biotechnologie UR12ES12, Faculté de Pharmacie de Monastir, Université de Monastir, Rue Avicenne, Monastir, Tunisia. E
[Ti] Título:Reversal of resistance in bacteria underlies synergistic effect of essential oils with conventional antibiotics.
[So] Source:Microb Pathog;106:50-59, 2017 May.
[Is] ISSN:1096-1208
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The pervasive of bacterial resistance earnestly threaten the prevention and the treatment of infectious diseases. Therefore, scientific communities take precedence over development of new antimicrobial agents. The aim of the study was to determine antimicrobial potency of three North-African essential oils Pituranthos chloranthus, Teucruim ramosissimum and Pistacia lentiscus individually, and in combination with antibiotics, to inhibit the growth of highly resistant clinical pathogen. Bacteria clinically isolated from patients, subsequently, challenged to a panel of drugs to determine the antibiotic-resistance profiles. Drugs displaying clinically irrelevant CMI were subjected to further studies in order to rescue antibiotic actions. Singular activity of essential oils and activity when combined with an antibiotic was hence elucidated. The results obtained highlighted the occurrence of strong antibacterial potential of essential oils when administrated alone. In the interactive experiment essential oils were found highly effective in reducing the resistance of Methicillin-resistant Staphylococcus aureus to amoxicillin, tetracycline, piperacillin, ofloxacin and oxacillin and resistance of Acinetobacter baumannii to amoxicillin and to ofloxacin in interactive manner. Furthermore, the results proved synergism among essential oils and both antibiotics ofloxacin and novobiocin against the Extended-Spectrum Beta-Lactamase producing E. coli (ESBL). Time kill kinetics was performed with a combination of sub-inhibitory concentrations to confirm the efficiency and killing rate of the combination over time. Further, the hypothetical toxicity of essential oils against human keratinocytes HaCat and murine spleenocytes were examined. The chemical composition of essential oils was assessed by GC/MS analysis and the major constituents found were sabinene, limonene, terpinen-4-ol, and ß-eudesmol.
[Mh] Termos MeSH primário: Anti-Infecciosos/farmacologia
Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos
Óleos Voláteis/farmacologia
Óleos Vegetais/farmacologia
[Mh] Termos MeSH secundário: Acinetobacter baumannii/efeitos dos fármacos
Amoxicilina/farmacologia
Animais
Bactérias/efeitos dos fármacos
Bactérias/patogenicidade
Linhagem Celular/efeitos dos fármacos
Proliferação Celular/efeitos dos fármacos
Sobrevivência Celular
Cicloexenos/química
Combinação de Medicamentos
Sinergismo Farmacológico
Escherichia coli/efeitos dos fármacos
Cromatografia Gasosa-Espectrometria de Massas/métodos
Seres Humanos
Queratinócitos/efeitos dos fármacos
Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos
Camundongos
Testes de Sensibilidade Microbiana/métodos
Monoterpenos/química
Novobiocina/farmacologia
Ofloxacino/farmacologia
Óleos Voláteis/química
Oxacilina/farmacologia
Piperacilina/farmacologia
Extratos Vegetais/química
Extratos Vegetais/farmacologia
Óleos Vegetais/química
Sesquiterpenos de Eudesmano/química
Baço/efeitos dos fármacos
Terpenos/química
Tetraciclina/farmacologia
Fatores de Tempo
beta-Lactamases/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Infective Agents); 0 (Cyclohexenes); 0 (Drug Combinations); 0 (Monoterpenes); 0 (Oils, Volatile); 0 (Plant Extracts); 0 (Plant Oils); 0 (Sesquiterpenes, Eudesmane); 0 (Terpenes); 17EC19951N (Novobiocin); 473-15-4 (beta-eudesmol); 562-74-3 (terpinenol-4); 7D1TL44GPC (sabinene); 804826J2HU (Amoxicillin); 9MC3I34447 (limonene); A4P49JAZ9H (Ofloxacin); EC 3.5.2.6 (beta-Lactamases); F8VB5M810T (Tetracycline); UH95VD7V76 (Oxacillin); X00B0D5O0E (Piperacillin)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171108
[Lr] Data última revisão:
171108
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161106
[St] Status:MEDLINE


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[PMID]:27799222
[Au] Autor:Gislason AS; Choy M; Bloodworth RA; Qu W; Stietz MS; Li X; Zhang C; Cardona ST
[Ad] Endereço:Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
[Ti] Título:Competitive Growth Enhances Conditional Growth Mutant Sensitivity to Antibiotics and Exposes a Two-Component System as an Emerging Antibacterial Target in Burkholderia cenocepacia.
[So] Source:Antimicrob Agents Chemother;61(1), 2017 Jan.
[Is] ISSN:1098-6596
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Chemogenetic approaches to profile an antibiotic mode of action are based on detecting differential sensitivities of engineered bacterial strains in which the antibacterial target (usually encoded by an essential gene) or an associated process is regulated. We previously developed an essential-gene knockdown mutant library in the multidrug-resistant Burkholderia cenocepacia by transposon delivery of a rhamnose-inducible promoter. In this work, we used Illumina sequencing of multiplex-PCR-amplified transposon junctions to track individual mutants during pooled growth in the presence of antibiotics. We found that competition from nontarget mutants magnified the hypersensitivity of a clone underexpressing gyrB to novobiocin by 8-fold compared with hypersensitivity measured during clonal growth. Additional profiling of various antibiotics against a pilot library representing most categories of essential genes revealed a two-component system with unknown function, which, upon depletion of the response regulator, sensitized B. cenocepacia to novobiocin, ciprofloxacin, tetracycline, chloramphenicol, kanamycin, meropenem, and carbonyl cyanide 3-chlorophenylhydrazone, but not to colistin, hydrogen peroxide, and dimethyl sulfoxide. We named the gene cluster esaSR for enhanced sensitivity to antibiotics sensor and response regulator. Mutational analysis and efflux activity assays revealed that while esaS is not essential and is involved in antibiotic-induced efflux, esaR is an essential gene and regulates efflux independently of antibiotic-mediated induction. Furthermore, microscopic analysis of cells stained with propidium iodide provided evidence that depletion of EsaR has a profound effect on the integrity of cell membranes. In summary, we unraveled a previously uncharacterized two-component system that can be targeted to reduce antibiotic resistance in B. cenocepacia.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Burkholderia cenocepacia/efeitos dos fármacos
[Mh] Termos MeSH secundário: Burkholderia cenocepacia/genética
Cloranfenicol/farmacologia
Ciprofloxacino/farmacologia
Farmacorresistência Bacteriana Múltipla/genética
Hidrazonas/farmacologia
Canamicina/farmacologia
Testes de Sensibilidade Microbiana
Novobiocina/farmacologia
Tetraciclina/farmacologia
Tienamicinas/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Hydrazones); 0 (Thienamycins); 14046-96-9 (carbonyl 3-chlorophenylhydrazone); 17EC19951N (Novobiocin); 59-01-8 (Kanamycin); 5E8K9I0O4U (Ciprofloxacin); 66974FR9Q1 (Chloramphenicol); F8VB5M810T (Tetracycline); FV9J3JU8B1 (meropenem)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170919
[Lr] Data última revisão:
170919
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161102
[St] Status:MEDLINE


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[PMID]:27829510
[Au] Autor:Moreira LB; Maranho LA; Baena-Nogueras RM; Lara-Martín PA; Martín-Díaz ML
[Ad] Endereço:São Paulo State University "Júlio de Mesquita Filho", Bioscience Institute. Pça. Infante D. Henrique, 11330-900, São Vicente, Brazil; Marine Sciences Institute, Federal University of Ceará, Fortaleza, 60165-081, Brazil. Electronic address: lburuaem@gmail.com.
[Ti] Título:Effects of novobiocin and methotrexate on the benthic amphipod Ampelisca brevicornis exposed to spiked sediments.
[So] Source:Mar Environ Res;122:169-177, 2016 Dec.
[Is] ISSN:1879-0291
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The marine amphipod Ampelisca brevicornis was used as model organism of benthic macrofauna to assess the possible adverse effects of pharmaceuticals bound to sediments. Organisms were exposed to sediment spiked with novobiocin (NOV) and methotrexate (MTX) for 10 days in order to estimate the acute toxicity (lethal effects) produced by the two compounds. The surviving organisms were pooled and analyzed to determine their sublethal responses associated with different phases of metabolism (enzyme activities in phases I and II), oxidative stress (antioxidant enzyme activities and lipid peroxidation), and genotoxicity (DNA damage in the form of strand breaks). No lethal or sublethal effects were observed in the amphipods exposed to NOV. For organisms exposed to sediments spiked with MTX the results were found to calculate the concentration that was lethal to 50% of the organisms exposed in the toxicity tests (LC of 30.36 ng/g). MTX also induced the metabolism of enzyme detoxification activities in phases I and II. Oxidative stress and DNA damage in particular were also observed, indicating responses associated with MTX's mechanism of action. Both mortality and the set of applied biomarkers allowed for the assessment of bioavailability, oxidative stress, and genotoxicity of NOV and MTX. The information obtained in this investigation can assist in ecological risk assessment of marine sediments contaminated by pharmaceuticals.
[Mh] Termos MeSH primário: Anfípodes/fisiologia
Metotrexato/toxicidade
Novobiocina/toxicidade
Poluentes Químicos da Água/toxicidade
[Mh] Termos MeSH secundário: Animais
Biomarcadores/metabolismo
Dano ao DNA
Monitoramento Ambiental
Sedimentos Geológicos/química
Peroxidação de Lipídeos/efeitos dos fármacos
Estresse Oxidativo
Testes de Toxicidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biomarkers); 0 (Water Pollutants, Chemical); 17EC19951N (Novobiocin); YL5FZ2Y5U1 (Methotrexate)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170303
[Lr] Data última revisão:
170303
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161111
[St] Status:MEDLINE



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