Ontology highlight
ABSTRACT:
PROVIDER: PRJNA997707 | ENA |
REPOSITORIES: ENA
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Project description:Evolution of antibiotic resistance in microbes is frequently achieved by acquisition of spontaneous mutations during antimicrobial therapy. Here we demonstrate that inactivation of a central regulator of iron homeostasis (fur) facilitates laboratory evolution of ciprofloxacin resistance in Escherichia coli. To decipher the underlying molecular mechanisms, we first performed a global transcriptome analysis and demonstrated a substantial reorganization of the Fur regulon in response to antibiotic treatment. We hypothesized that the impact of Fur on evolvability under antibiotic pressure is due to the elevated intracellular concentration of free iron and the consequent enhancement of oxidative damage-induced mutagenesis. In agreement with expectations, over-expression of iron storage proteins, inhibition of iron transport, or anaerobic conditions drastically suppressed the evolution of resistance, while inhibition of the SOS response-mediated mutagenesis had no such effect in fur deficient population. In sum, our work revealed the central role of iron metabolism in de novo evolution of antibiotic resistance, a pattern that could influence the development of novel antimicrobial strategies. We used microarrays to identify genotype specific transcriptional changes under severe DNA damaging conditions (antibiotic ciprofloxacin). We treated Escherichia coli cells with a highly toxic level of ciprofloxacin (gyrase inhibitor) for RNA extraction and hybridization on Affymetrix microarrays. We planned to find genotype specific transcriptional responses using WT control (BW25113) and fur-knockout mutant (selected from the KEIO collection) strains during antibiotic treatments. For each treatment type we used two biological replicates.
2014-09-11 | E-GEOD-55662 | biostudies-arrayexpress
Project description:Evolution of antibiotic resistance in microbes is frequently achieved by acquisition of spontaneous mutations during antimicrobial therapy. Here we demonstrate that inactivation of a central regulator of iron homeostasis (fur) facilitates laboratory evolution of ciprofloxacin resistance in Escherichia coli. To decipher the underlying molecular mechanisms, we first performed a global transcriptome analysis and demonstrated a substantial reorganization of the Fur regulon in response to antibiotic treatment. We hypothesized that the impact of Fur on evolvability under antibiotic pressure is due to the elevated intracellular concentration of free iron and the consequent enhancement of oxidative damage-induced mutagenesis. In agreement with expectations, over-expression of iron storage proteins, inhibition of iron transport, or anaerobic conditions drastically suppressed the evolution of resistance, while inhibition of the SOS response-mediated mutagenesis had no such effect in fur deficient population. In sum, our work revealed the central role of iron metabolism in de novo evolution of antibiotic resistance, a pattern that could influence the development of novel antimicrobial strategies. We used microarrays to identify genotype specific transcriptional changes under severe DNA damaging conditions (antibiotic ciprofloxacin).
2014-09-11 | GSE55662 | GEO
Project description:Pseudomonas aeruginosa infections can be virtually impossible to eradicate and the evolution of resistance during antibiotic therapy is a significant concern. In this study, we use DNA microarrays to characterize the global transcriptional response of P. aeruginosa to clinical-like doses of the antibiotic ciprofloxacin and also to determine the component that is regulated by LexA cleavage and the SOS response. We find that genes involved in virtually every facet of metabolism are down-regulated in response to ciprofloxacin. The LexA-controlled SOS regulon identified by microarray analysis includes only fifteen genes, but does include several genes that encode proteins involved in recombination and replication, including two inducible polymerases known to play a role in mutation and the evolution of antibiotic resistance in other organisms. The data suggests that the inhibition of LexA cleavage during therapy might help combat this pathogen by decreasing its ability to adapt and evolve resistance. Keywords: Time course of response of P. aeruginosa to the antibiotic ciprofloxacin
2006-08-04 | GSE5443 | GEO
Project description:Understanding constraints which shape antibiotic resistance is key for predicting and controlling drug resistance. Here, we performed high-throughput laboratory evolution of Actinobacillus pleuropneumoniae and its ciprofloxacin resistance-inducing derivatives.This study aims to explore the mechanism of acquired ciprofloxacin resistance in Actinobacillus pleuropneumoniae.
2021-10-06 | GSE181030 | GEO
Project description:Pseudomonas aeruginosa infections can be virtually impossible to eradicate and the evolution of resistance during antibiotic therapy is a significant concern. In this study, we use DNA microarrays to characterize the global transcriptional response of P. aeruginosa to clinical-like doses of the antibiotic ciprofloxacin and also to determine the component that is regulated by LexA cleavage and the SOS response. We find that genes involved in virtually every facet of metabolism are down-regulated in response to ciprofloxacin. The LexA-controlled SOS regulon identified by microarray analysis includes only fifteen genes, but does include several genes that encode proteins involved in recombination and replication, including two inducible polymerases known to play a role in mutation and the evolution of antibiotic resistance in other organisms. The data suggests that the inhibition of LexA cleavage during therapy might help combat this pathogen by decreasing its ability to adapt and evolve resistance. Experiment Overall Design: Sample preparation and data analysis. For each strain (PAO1 and the lexA uninducible mutant), 5 clones were inoculated in LB and grown 18 h. Cultures were diluted 1:500 and grown to mid-log phase (OD600 ~0.4-0.5) at which point ciprofloxacin was added to a final concentration of 1 μg/ml. At 0, 30 and 120 minutes following ciprofloxacin addition, appropriate volumes from each of the 5 cultures per strain were pooled and added to 2 volumes of RNAprotect reagent (Qiagen); cell pellets were stored at 4 ºC until RNA extraction. Total RNA was extracted using the RNeasy Mini kit (Qiagen) at the end of the sample collection period. This procedure was repeated three independent times to generate three samples each just prior to and 120 minutes post ciprofloxacin addition.
2007-09-21 | E-GEOD-5443 | biostudies-arrayexpress
Project description:The rise of antibiotic resistance in many bacterial pathogens has been driven by the spread of a few successful strains, suggesting that some bacteria are genetically pre-disposed to evolving resistance. We tested this hypothesis by challenging a diverse set of 222 strains of Staphylococcus aureus with the antibiotic ciprofloxacin in a large-scale evolution experiment. Surprisingly, we found that a single efflux pump, norA, causes widespread variation in evolvability across the diversity of S. aureus. In most lineages of S. aureus, elevated norA expression potentiated evolution by increasing the fitness benefit provided by resistance mutations in DNA topoisomerase under ciprofloxacin treatment. Amplification of norA provided a further mechanism of rapid evolution, but this was restricted to strains from CC398. Crucially, chemically inhibiting NorA effectively prevented the evolution of resistance across the diversity of S. aureus. Our study shows that the underlying genetic diversity of pathogenic bacteria plays a key role in shaping resistance evolution. Understanding this link makes it possible to predict which strains are likely to evolve resistance and to optimize inhibitor use to prevent this outcome.
2020-07-05 | GSE150762 | GEO
Project description:Background: Antibiotic resistance is an urgent threat to public health. Prior to the evolution of antibiotic resistance, bacteria frequently undergo response and tend to develop a state of adaption to the antibiotic. Ciprofloxacin is a broad-spectrum antibiotic by damaging DNA. With the widespread clinical application, the resistance of bacteria to ciprofloxacin continues to increase. This study aimed to investigate the transcriptome changes under the action of high concentration of ciprofloxacin in Escherichia coli. Results: We identified 773 up-regulated differentially expressed genes (DEGs) and 645 down-regulated DEGs in ciprofloxacin treated cells. Enriched biological pathways reflected the up-regulation of biological process such as DNA damage and repair system, toxin/antitoxin systems, formaldehyde detoxification system, peptide biosynthetic process and cellular protein metabolic process. With KEGG pathway analysis, up-regulated DEGs of kdsA and waa operon were associated with “LPS biosynthesis”. rfbABC operon was related to “streptomycin biosynthesis” and “polyketide sugar unit biosynthesis ”. Down-regulated DEGs of thrABC and fliL operons were associated with “flagellum-dependent cell motility” and “bacterial-type flagellum” in GO terms, and enriched into “biosynthesis of amino acids” and “flagellar assembly” in KEGG pathways. After treatment of ciprofloxacin, bacterial lipopolysacchride (LPS) release was increased by two times, and the mRNA expression level of LPS synthesis genes, waaB, waaP and waaG were elevated (P < 0.05). Conclusions: Characterization of the gene clusters by RNA-seq showed high dose of ciprofloxacin not only lead to damage of bacterial macromolecules and components, but also induce protective response against antibiotic action by up-regulating the SOS system, toxin/antitoxin system and formaldehyde detoxification system. Moreover, genes related to biosynthesis of LPS were also upregulated by the treatment indicating that ciprofloxacin can enhance the production of endotoxin on the level of transcription. These results demonstrated that transient exposure of high dose ciprofloxacin is double edged. Cautions should be taken when administering the high dose antibiotic treatment for infectious diseases.
2020-06-16 | GSE152445 | GEO
Project description:We employed a genome-wide microarray approach to obtain a profile of the transcriptional events in ciprofloxacin-treated EPEC shedding light on how ciprofloxacin affects EPEC transcriptional events and growth, aside from resistance mechanisms, and how this bacterium tolerates antibiotic stress.
2015-12-15 | GSE75988 | GEO
Project description:Yersinia pseudotuberculosis is a Gram-negative bacterium capable of causing gastrointestinal infection and is closely related to the highly virulent plague bacillus Yersinia pestis. Infection by both species are currently treatable with antibiotics such as ciprofloxacin, a quinolone-class drug of major clinical importance in the treatment of many other infections. Our current understanding of the mechanism of action of ciprofloxacin is that it inhibits DNA replication by targeting DNA gyrase, and that resistance is primarily due to mutation at this target site, along with generic efflux and detoxification strategies. We utilised transposon directed insertion site sequencing (TraDIS or TnSeq) to identify the non-essential chromosomal genes in Y. pseudotuberculosis that are required to tolerate sub-lethal concentrations of ciprofloxacin in vitro. As well as highlighting recognised antibiotic resistance genes, we provide evidence that a multitude of genes involved in regulating DNA replication and repair are central in enabling Y. pseudotuberculosis to tolerate the antibiotic, including dksA (yptb0734), a regulator of RNA polymerase and hda (yptb2792), an inhibitor of DNA replication initiation. We furthermore demonstrate that even at sub-lethal concentrations, ciprofloxacin causes severe cell-wall stress, requiring lipopolysaccharide lipid A, O-antigen and core biosynthesis genes to resist the sub-lethal effects of the antibiotic. It is evident that coping with the consequence(s) of antibiotic-induced stress requires the contribution of scores of genes that are not exclusively engaged in drug-resistance.
2019-08-02 | GSE135236 | GEO
Project description:We employed a genome-wide microarray approach to obtain a profile of the transcriptional events in ciprofloxacin-treated EPEC shedding light on how ciprofloxacin affects EPEC transcriptional events and growth, aside from resistance mechanisms, and how this bacterium tolerates antibiotic stress. Sample of each culture immediately after the addition of ciprofloxacin (t0), 45 min (t45), 90 min (t90), 135 min (t135), and 180 min (t180), ciprofloxacin induced gene expression in EPEC Deng strain were measure by microarray statistical analysis
2015-12-15 | E-GEOD-75988 | biostudies-arrayexpress