Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1096674 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Efflux of antimicrobial compounds from bacterial cells is one of the important mechanisms responsible for multi-drug resistance (MDR). Inhibiting the activity of efflux pumps using chemosensitizers like 1-(1-naphthylmethyl)-piperazine (NMP) is currently considered as a promising strategy to overcome MDR. However, additional effects of NMP other than inhibition are rarely if ever considered. Here, using phenotypic, phenotypic microarray and transcriptomic assays we show that NMP plays a role in membrane destabilization in MDR Klebsiella pneumoniae MGH 78578 strain. The observation of membrane destabilization was supported by RNA-seq data which showed that many up-regulated genes were either directly involved in responses to envelope stress or bacterial repair systems which are essential to maintain viability in an environment containing NMP. Membrane destabilization happens as early as 15 minutes post-NMP treatment. We postulate that the early membrane disruption leads to destabilization of inner membrane potential, impairing ATP production and consequently resulting in efflux pump inhibition.
2018-12-06 | GSE122651 | GEO
Project description:Antimicrobial exposure can potentially lead to increased antimicrobial resistance plasmid transfer. RNA sequencing data was collected from conjugal pairs of Salmonella enterica and Escherichia coli exposed or not exposed to tetracycline over a time course to determine differences in transcript numbers associated with conjugation and tetracycline exposure. The samples were sequenced on the Illumina HiSeq X10 platform with the 150-bp paired-end kit. Among the most highly up-regulated genes in the tetracycline exposed samples were also tetracycline efflux pump genes across the timepoints. In addition, some conjugal transfer-associated genes (e.g. traJ and traA) were upregulated in the tetracycline exposed samples.
2024-03-25 | GSE261094 | GEO
Project description:Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses expression of mtrF, which encodes a putative inner membrane protein that works with the MtrC-MtrD-MtrE efflux pump to allow gonococci to resist high levels of multiple hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (Ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates expression of drug efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes the direct transcriptional repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late-logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. MpeR-mediated repression of mtrR appeared to be direct, as judged by DNA-binding analyses, and was enhanced by conditions of iron-limitation, which resulted in increased expression of the mtrCDE efflux pump operon. Taken together, our results indicate that both genetic and physiologic parameters can influence expression of the mtr efflux system and that these can modulate levels of gonococcal susceptibility to efflux pump substrates.
2012-04-04 | GSE32717 | GEO
Project description:The objective of the current study was to understand the glutaraldehyde resistance mechanisms in P. fluorescens and P. aeruginosa biofilms. Glutaraldehyde is a common biocide used in various industries to control the microbial growth. Recent reports of emergence of glutaraldehyde resistance in several bacterial species motivated this study to understand the genetic factors responsible got glutaraldehyde resistance. Using a combination of phenotypic assays, chemical genetic assays and RNA-seq, we demonstrate that novel efflux pump, polyamine biosynthesis, lipid biosynthesis and phosphonate degradation play significant role in glutaraldehyde resistance and post-glutaraldehyde recovery of Psudomonad biofilms.
2015-04-06 | GSE64448 | GEO
Project description:Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses expression of mtrF, which encodes a putative inner membrane protein that works with the MtrC-MtrD-MtrE efflux pump to allow gonococci to resist high levels of multiple hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (Ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates expression of drug efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes the direct transcriptional repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late-logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. MpeR-mediated repression of mtrR appeared to be direct, as judged by DNA-binding analyses, and was enhanced by conditions of iron-limitation, which resulted in increased expression of the mtrCDE efflux pump operon. Taken together, our results indicate that both genetic and physiologic parameters can influence expression of the mtr efflux system and that these can modulate levels of gonococcal susceptibility to efflux pump substrates. two strains, two growth phases, three replicates each.
2012-04-03 | E-GEOD-32717 | biostudies-arrayexpress
Project description:Membrane efflux pumps play a major role in bacterial multidrug resistance. The tripartite multidrug efflux pump system from Escherichia coli, AcrAB-TolC, is a target for inhibition to lessen resistance development and restore antibiotic efficacy, with homologs in other ESKAPE pathogens. Here, we rationalize a mechanism of inhibition against the periplasmic adaptor protein, AcrA, using a combination of hydrogen/deuterium exchange mass spectrometry, cellular efflux assays, and molecular dynamics simulations. We define the structural dynamics of AcrA and find that an inhibitor can inflict long-range stabilisation across all four of its domains, whereas an interacting efflux substrate has minimal effect. Our results support a model where an inhibitor forms a molecular wedge within a cleft between the lipoyl and αβ domains of AcrA, diminishing its conformational transmission of drug-evoked signals from AcrB to TolC. This work provides molecular insights into multidrug adaptor protein function which could be valuable for developing antimicrobial therapeutics.
2023-06-01 | PXD041359 | Pride
Project description:Tuberculosis (TB) is an ancient disease caused by the intracellular bacterial pathogen Mycobacterium tuberculosis (Mtb). The rise of antimicrobial resistance (AMR) threatens to bring Mtb to the forefront of bacterial pathogens as the current treatments are increasingly becoming ineffective. Understanding the development of AMR and the virulence processes of Mtb is crucial for the identification of new drug targets and the rational design of anti-TB treatments. One of the established mechanisms of resistance is through the function of efflux proteins, which are transmembrane transporters that bind and remove antibiotic molecules out from the cell. Here, we determine the role of Rv3728, a major facilitator superfamily (MFS) efflux pump protein, which also predicted to bind 3',5'-cyclic adenosine monophosphate (cAMP). Using bioinformatic tools and cAMP binding assay, we confirm that Rv3728 binds to cAMP and identified E597 and R606 as important residues involved in binding. Although Rv3728 deletion has no impact on bacterial resistance and tolerance to different antibiotics, it affects membrane permeability and alters the acylation profile of phosphatidyl-myo-inositol mannosides lipids.
2024-06-10 | GSE268977 | GEO
Project description:Target (MexB) and efflux based mechanisms decreasing the effectiveness of the efflux pump inhibitor D13-9001 in P. aeruginosa PAO1: uncovering a new role for MexMN-OprM in efflux of β-lactams and a novel regulatory circuit (MmnRS) controlling MexMN expression Efflux pumps contribute to antibiotic resistance in Gram-negative pathogens. Correspondingly, efflux pump inhibitors (EPIs) may reverse this resistance. D13-9001 specifically inhibits MexAB-OprM in P. aeruginosa. Mutants with decreased susceptibility to MexAB-OprM inhibition by D13-9001 were identified and these fell into two categories; those having alterations in the target MexB (F628L and ΔV177) and those with mutations in PA1438 (L172P substitution) which encoded a putative sensor kinase of unknown function. The alterations in MexB were consistent with reported structural studies of D13-9001 interaction with MexB. The PA1438L172P alteration mediated a >150-fold upregulation of MexMN pump gene expression and >50-fold upregulation of PA1438 and the neighboring response regulator gene PA1437. We propose that these be renamed as mmnR/mmnS for MexMN Regulator and Sensor. MexMN was shown to partner with the outer membrane channel protein OprM and to pump several β-lactams, monobactams and tazobactam. Upregulated MexMN functionally replaced MexAB-OprM to efflux these compounds but was insusceptible to inhibition by D13-9001. MmnSL172P also mediated a decrease in susceptibility to imipenem / biapenem that was independent of MexMN-OprM. Expression of oprD, encoding the uptake channel for these compounds was downregulated, suggesting that this channel is also part of the MmnSR regulon. RNA-seq of cells encoding MmnSL172P revealed among other things an interrelationships between regulation of mexMN and genes involved in heavy metal resistance.
2018-12-07 | GSE123403 | GEO
Project description:The objective of the current study was to understand the glutaraldehyde resistance mechanisms in P. fluorescens and P. aeruginosa biofilms. Glutaraldehyde is a common biocide used in various industries to control the microbial growth. Recent reports of emergence of glutaraldehyde resistance in several bacterial species motivated this study to understand the genetic factors responsible got glutaraldehyde resistance. Using a combination of phenotypic assays, chemical genetic assays and RNA-seq, we demonstrate that novel efflux pump, polyamine biosynthesis, lipid biosynthesis and phosphonate degradation play significant role in glutaraldehyde resistance and post-glutaraldehyde recovery of Psudomonad biofilms. Examination of P. fluorescens 72 h biofilm transcriptome was elucidated upon exposure to glutaraldehyde. The results were confirmed using qRT--PCR and chemical genetic appraoches in P. fluorescens and P. aeruginosa.
2015-04-06 | E-GEOD-64448 | biostudies-arrayexpress
Project description:Peptides have great potential to combat antibiotic resistance. While many platforms can screen peptides for their ability to bind to target cells, there are virtually no platforms that directly assess the functionality of peptides. This limitation is exacerbated when identifying antimicrobial peptides, since the phenotype, death, selects against itself, and has caused a scientific bottleneck confining research to only a few naturally occurring classes of antimicrobial peptides. We have used this seeming dissonance to develop Surface Localized Antimicrobial displaY (SLAY); a platform that allows screening of unlimited numbers of peptides of any length, composition, and structure in a single tube for antimicrobial activity. Using SLAY, we screened ~800,000 random peptide sequences for antimicrobial function and identified thousands of active sequences doubling the number of known antimicrobial sequences. SLAY hits present with different potential mechanisms of peptide action and access to areas of antimicrobial physicochemical space beyond what nature has evolved.
2018-01-03 | GSE94530 | GEO