Escherichia coli
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA107537 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The number and overlapping substrate repertoire of multidrug efflux pumps in the E. coli genome suggest a physiological role apart from multidrug resistance. This role was investigated using transcriptomic analyses of cDNAs labeled from E. coli AG102 mRNA (hyper drug resistant, marR1) and its isogenic major efflux pump mutants. Keywords: Mutation Analysis
2008-03-11 | GSE10757 | GEO
Project description:We present here a transcriptional regulator, PA3898, which controls biofilm formation and multidrug efflux-pumps in P. aeruginosa. A mutant of this regulator significantly reduced the ability of P. aeruginosa to produce biofilm in vitro, and affected its in vivo fitness and pathogenesis in Drosophila melanogaster and BALB/c mouse lung infection models. Transcriptome analysis revealed that PA3898 modulates essential virulence genes/pathways, including multidrug efflux-pumps and phenazine biosynthesis.
2018-09-16 | GSE120009 | GEO
Project description:Expression of efflux pumps is a key feature of most cells which are resistant to multiple antibiotics. This study used TraDIS-Xpress, a genome wide transposon mutagenesis technology to identify genes in Escherichia coli and Salmonella Typhimurium involved in drug efflux and its regulation. We exposed mutant libraries to the canonical efflux substrate acriflavine in the presence and absence of the efflux inhibitor phenylalanine-arginine β-naphthylamide. Comparisons between conditions identified efflux specific and drug specific responses. Known efflux associated genes were easily identified including: AcrAB-TolC, MarA, RamA and SoxS confirming specificity of the response. Further genes encoding cell envelope maintenance enzymes and products involved with stringent response activation, DNA housekeeping, respiration and glutathione biosynthesis were also identified as affecting efflux activity in both species. We identified a conserved set of pathways crucial for efflux activity in these experimental conditions which expands the list of genes known to impact efflux efficacy.
2022-11-12 | E-MTAB-12353 | biostudies-arrayexpress
Project description:We present here a transcriptional regulator, PA3898, which controls biofilm formation and multidrug efflux-pumps in P. aeruginosa. A mutant of this regulator significantly reduced the ability of P. aeruginosa to produce biofilm in vitro, and affected its in vivo fitness and pathogenesis in Drosophila melanogaster and BALB/c mouse lung infection models. Transcriptome analysis revealed that PA3898 modulates essential virulence genes/pathways, including multidrug efflux-pumps and phenazine biosynthesis.ChIP-seq identified its DNA binding sequences and confirmed PA3898 directly interacts with promoter regions of four genes/operons, two of which are mexAB-oprM and phz2.
2018-09-18 | GSE120082 | GEO
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:Efflux pumps are a significant challenge for the development of new antibacterial agents. Overcoming efflux requires an in-depth understanding of efflux pump functions, substrate specificities, and the development of inhibitors. However, the complexities of drug efflux networks have limited such studies. To address these challenges, we report the generation of Efflux KnockOut-35 (EKO-35), a highly susceptible Escherichia coli strain lacking 35 efflux pumps. We demonstrate the utility of this strain by constructing an efflux platform consisting of strains individually expressing genes encoding efflux pumps forming tripartite complexes with the outer membrane channel TolC. This platform was profiled against a curated diverse compound collection, which enabled us to define physicochemical properties that contribute to transport. We also show the E. coli drug efflux network is conditionally essential for growth, and that the platform can be used to investigate efflux pump inhibitor specificities and also efflux pump interplay. We believe EKO-35 and the efflux platform will have widespread application for the study of drug efflux.
2022-08-31 | PXD033975 | Pride
Project description:Found how E. coli responds to the commonly prescribed antibiotic-inhibitor combination piperacillin and tazobactam, separately and in combination. TraDIS-Xpress was performed following the protocol outlined by Yasir et al 2020 Genome Research. The results suggest tazobactam triggers the activity of multidrug efflux systems that have been previously seen to confer clinical resistance to multiple classes of antibiotics.
2023-08-31 | E-MTAB-13226 | biostudies-arrayexpress
Project description:One of the key issues affecting yields of biovanillin in cell factories such as Escherichia coli is product toxicity, the mechanisms of which are poorly understood. To identify targets for engineering improved strains, we have studied mechanisms of vanillin toxicity in E. coli using a two-pronged apparoach: (i) a global proteomic analysis supported by multiple physiological experiments and mutant analyses (ii) adaptive laboratory evolution (ALE) of vanillin tolerance combined with genome sequencing. We identified 147 proteins that exhibited a significant change in abundance in response to vanillin. Upregulated proteins included enzymes capable of converting aldehydes to potentially less toxic compounds; pentose phosphate pathways enzymes, fumarase C and enzymes of the glyoxylate shunt; proteins involved in several key stress responses, in particular oxidative stress; proteins mediating uptake and processing of metal ions. 1H-NMR confirmed that E. coli detoxifies vanillin by reduction to vanillyl alcohol; the aldehyde reductases YqhD and DkgA were highly upregulated by vanillin and the purified enzymes reduced vanillinin an NADPH dependent manner. Vanillin caused accumulation of reactive oxygen species and activated an oxidative stress response through SoxRS, OxyR and MarA pathways. Slow vanillin dependent copper (II) to copper (I) reduction lead to upregulation of the copA gene and growth in the presence of vanillin was hypersensitive to inhibition by copper ions. RT-PCR and mutant growth data suggested AcrD and AaeAB as potential vanillin efflux systems. Vanillin-tolerant strains isolated by ALE had distinct non-synonymous SNPs in the citrate synthase gene gltA, in addition to strain specific mutations in cpdA, rob and marC. One strain had a large ~10 kb deletion including the marRAB region. Purifed variant GltA enzymes all showed higher activity due to a lowered Km for oxaloacetate. Our data provide new understanding and novel gene targets for engineering vanillin-tolerant strains of E. coli, including deletion of the efflux pumps eamA, acrA, and acrB, enhancing oxidative stress defences and NADPH production, improving copper homeostasis and increasing citrate synthase activity using variant enzymes.
2019-05-29 | PXD009242 | Pride
Project description:The antibiotic fosfomycin is widely recognized for treatment of lower urinary tract infections caused by Escherichia coli and lately gained importance as a therapeutic option to combat multidrug resistant bacteria. Still, resistance to fosfomycin frequently develops through mutations reducing its uptake. Whereas the inner membrane transport of fosfomycin has been extensively studied in E. coli, its outer membrane (OM) transport remains insufficiently understood. While evaluating minimal inhibitory concentrations in OM porin-deficient mutants, we observed that the E. coli ΔompCΔompF strain is five times more resistant to fosfomycin than the wild type and the respective single mutants. Continuous monitoring of cell lysis of porin-deficient strains in response to fosfomycin additionally indicated the relevance of LamB. Furthermore, the physiological relevance of OmpF, OmpC and LamB for fosfomycin uptake was confirmed by electrophysiological and transcriptional analysis. This study expands the knowledge of how fosfomycin crosses the OM of E. coli.
2024-01-24 | GSE236554 | GEO
Project description:Commensal microbes are exposed to enterohepatically circulated steroids such as bile acids and hormones in the gastrointestinal, vaginal, and urinary tracts. Since commensal microbes are exposed to these molecules exclusively in association with their host, we hypothesized that they may serve as effectors to identify and characterize genetic pathways involved in the commensal-host relationship. Host specific and some ingested steroids (phytoestrogens) are enterohepatically circulated through the lumen of the small intestine. Bile acid steroids are present at high concentrations, approximating 4 to 20 mM in the duodenum, and are released in bile from the common bile duct. Steroid hormones are secreted in bile at levels approximating 6 to 13 mg per day once conjugated to glucuronide or sulfate by the liver. Re-absorption of steroids by the terminal ileum is an incomplete process: for example, 200 to 600 mg of bile acid steroids per day in humans escape to the colon where complex microbial populations exist. We have shown that steroid hormones estradiol, progesterone, and hydrocortisone serve as strong substrates for the major RND- and MFS-type (except hydrocortisone) tripartite multidrug efflux systems, AcrAB-TolC and EmrAB-TolC respectively, even though such molecules fail to demonstrate antimicrobial properties in this bacterial background (Elkins and Mullis [2006] J. Bacteriol. 188:1191-1195). Although bile acids are subject to efflux, they are also known to directly interact with intracellular global regulators such as MarR (Prouty et al. [2004] Microbiol. 150:775-783) and Rob (Rosenberg et al., [2003] Mol. Microbiol. 48:1609-1619) consequently altering antimicrobial and bile resistance profiles. In our present study, whole-genome DNA microarrays of E. coli were used to determine what general effect steroids, both bile acid and hormones, may have on the transcriptome in relation to the human commensal environment. Keywords: Comparative Chemical Class Treatment
2008-03-14 | GSE10811 | GEO