Project description:Fis is a nucleoid-associated protein in E. coli that is abundant during early logarithmic growth in rich medium but is in short supply during stationary phase. Its role as a transcriptional regulator has been demonstrated for an increasing number of genes. In order to gain insight into the global effects of Fis on E. coli gene expression during different stages of growth in rich medium, DNA microarray analyses were conducted in fis and wild type strains during early log, mid log, late log, and stationary growth phases. We used microarrays to detail the global impact of Fis on gene expression in Escherichia coli Experiment Overall Design: E.coli cells were were grown and samples were taken at different times during growth: 90 min (early logarithmic phase), 150 min (mid-logarithmic phase), 240 min (late logarithmic phase), and 360 min (early stationary phase) for RNA extraction and hybridization on Affymetrix microarrays. This was done in triplicate and the raw data was analyzed using Microarray Analysis Suite version 5.0 (Affymetrix).
Project description:This SuperSeries is composed of the following subset Series:; GSE7379: Fis KO strain; GSE7380: WT (Fis+) strain Experiment Overall Design: Refer to individual Series
Project description:Effect of acyl-HSL signal or ectopic lasR, rhlR, or rpoS expression on the advancement of quorum sensing gene expression during the logarithmic phase of growth
Project description:Drugs targeting DNA and RNA in mammalian cells or viruses can also affect bacteria present in the host and thereby induce the bacterial SOS system. This has the potential to increase mutagenesis and the development of antimicrobial resistance (AMR). Here we have examined nucleoside analogues (NAs) commonly used in anti-viral and anti-cancer therapies for potential effects on mutagenesis in Escherichia coli using the Rifampicin mutagenicity assay. To further explore the mode of action of the NAs, we appliedanalyzed metabolome and proteome of E.coli deletion mutants., and metabolome and proteome analyses. Five out of the thirteen NAs examined, including three nucleoside reverse transcriptase inhibitors (NRTIs) and two anti-cancer drugs, increased the mutation frequency in E. coli more than 25-fold at doses that were within reported plasma concentration range (Pl.CR), but that did not affect bacterial growth. We show that the SOS response is induced and that the increase in mutation frequency is mediated by the TLS polymerase Pol V. Quantitative mass spectrometry based metabolite profiling did not reveal large changes in nucleoside phosphate or other central carbon metabolite pools, which suggests that the SOS induction is an effect of increased replicative stress. Our results suggest that NAs/NRTIs can contribute to the development of AMR.
Project description:Background: Pseudomonas aeruginosa, a pathogen infecting those with cystic fibrosis, encounters toxicity from phagocyte-derived reactive oxidants including hydrogen peroxide during active infection. P. aeruginosa responds with adaptive and protective strategies against these toxic species to effectively infect humans. Despite advances in our understanding of the responses to oxidative stress in many specific cases, the connectivity between targeted protective genes and the rest of cell metabolism remains obscure. Results: Herein, we performed a genome-wide transcriptome analysis of the cellular responses to hydrogen peroxide in order to determine a more complete picture of how oxidative stress-induced genes are related and regulated. Our data reinforce the previous conclusion that DNA repair proteins and catalases may be among the most vital antioxidant defense systems of P. aeruginosa. Our results also suggest that sublethal oxidative damage reduces active and/or facilitated transport and that intracellular iron might be a key factor for a relationship between oxidative stress and iron regulation. Perhaps most intriguingly, we revealed that the transcription of all F-, R-, and S-type pyocins was upregulated by oxidative stress and at the same time, a cell immunity protein (pyocin S2 immunity protein) was downregulated, possibly leading to self-killing activity. Conclusions: This finding proposes that pyocin production might be another novel defensive scheme against oxidative attack by host cells. Experiment Overall Design: We conducted four and five independent microarray experiments with biological replicates in the absence (control) and the presence (experimental) of hydrogen peroxide, respectively.
Project description:In the present study, we employed Affymetrix Pseudomonas aeruginosa GeneChip arrays to investigate global gene expression profiles during the cellular response of Pseudomonas aeruginosa to sodium hypochlorite Experiment Overall Design: We calculated fold change as the ratio between the signal averages of four untreated (control) and five sodium hypochlorite-treated (experimental) cultures for 20 min exposure.
Project description:E. coli ΔarcZ hfq-Flag strain was transformed with a WT arcZ, mut arcZC81G or a mut arcZC81T,T82G,G83A plasmids. Single colonies of the transformants were grown overnight in LB at 37 °C with shaking (200 r.p.m.). Cultures were diluted 100-fold in fresh LB re-grown with shaking at 37 °C to an optical density of OD600 = 1.0 and induced with IPTG (1mM, 20 min), RIL-seq experiments were preformed as described in Melamed et al 2018, each repeated three times.
Project description:In the present study, we employed Affymetrix Staphylococcus aureus GeneChip arrays to investigate the dynamics of global gene expression profiles during the cellular response of Staphylococcus aureus to Ortho-Phenylphenol, which involved initial growth inhibition and metabolism. Keywords: Time course We conducted five independent microarray experiments (biological replicates) in the absence (control) and the presence (experimental) of Ortho-Phenylphenol. We calculated fold change as the ratio between the signal averages of five untreated (control) and five ortho-phenylphenol-treated (experimental) cultures for 0, 20 and 60 min exposures.
Project description:Fis is a nucleoid-associated protein in E. coli that is abundant during early logarithmic growth in rich medium but is in short supply during stationary phase. Its role as a transcriptional regulator has been demonstrated for an increasing number of genes. In order to gain insight into the global effects of Fis on E. coli gene expression during different stages of growth in rich medium, DNA microarray analyses were conducted in fis and wild type strains during early log, mid log, late log, and stationary growth phases. We used microarrays to detail the global impact of Fis on gene expression in Escherichia coli Experiment Overall Design: E.coli cells were were grown and samples were taken at different times during growth: 90 min (early logarithmic phase), 150 min (mid-logarithmic phase), 240 min (late logarithmic phase), and 360 min (early stationary phase) for RNA extraction and hybridization on Affymetrix microarrays. This was done in triplicate and the raw data was analyzed using Microarray Analysis Suite version 5.0 (Affymetrix).