Transcription profiling of Enterococcus faecalis V583 treated with SDS and bovine bile
ABSTRACT: The effects of bovine bile and SDS on transcriptional events were studied by means of genome wide microarrays in Enterococcus faecalis V583. Transcriptional profiles were obtained through time series experiments over periods of 120min for cells treated with bile and the combination of SDS and bile, and 360min. for SDS.
Applied and environmental microbiology 20070727 18
Resistance to bile is a prerequisite property of the gastrointestinal bacterial flora. Bile acids are powerful detergents, and resistance to sodium dodecyl sulfate (SDS) has therefore often been considered relevant to studies of bile resistance. We have studied the effects of bovine bile (BB) and SDS on Enterococcus faecalis V583 by traditional growth studies and microarrays. Transcriptional responses were studied by time course experiments. In the presence of BB (V583-BB) or SDS (V583-SDS), 308 ...[more]
Project description:The effects of NaCl on transcriptional events were studied by means of genome wide microarrays in Enterococcus faecalis V583. Transcriptional profiles were obtained through time series experiments over periods of 60min.
Project description:Streptococcus pneumoniae D39 AdcR (adhesion competence repressor) is the first metal-sensing member of the MarR (multiple antibiotic resistance repressor) family to be characterized. Expression profiling of a ∆adcR strain grown in liquid culture under microaerobic conditions revealed that transcript amounts for 13 genes were up-regulated relative to the wild-type strain, among them adcR, adcCBA, encoding a high affinity ABC uptake system for zinc, and genes encoding cell-surface zinc-binding pneumococcal histidine triad (pht) and adcII (lmb, laminin binding) proteins. Down-regulated transcripts included those encoding two putative zinc-containing alcohol dehydrogenases. Bacterial strains were grown exponentially in rich (BHI) media at 37C and an atmosphere of 5% CO2 to OD620~0.2, and were processed as described in the related Sample records. Samples were collected from three independent biological replicates and included one dye swap. Data were normalized using the Lowess (block) method without background subtraction. Changes in relative transcript amounts of positive or negative 2-fold with Bayesian P value of <0.001 were considered significant, and were included as supplementary material for the accompanying manuscript (The metalloregulatory site in Streptococcus pneumoniae AdcR, a zinc-activated MarR-family repressor; Reyes-Caballero, H. et al, manuscript in preparation).
Project description:These studies were designed to examine the acute Listeria monocytogenes transcriptional response to mammalian (porcine) bile. Triplicate WT Listeria monocytogenes (strain 10403S) were grown to mid-log in BHI at 37 °C. Samples were divided, and either treated or not treated by addition of porcine bile (Sigma, to 1% final) for 30 minutes.
Project description:Differences in gene content between three test strains were first assessed by comparative genomic hybridization using an E. faecalis V583 oligo array and with E. faecalis V583 as a reference strain . Transcriptional profiles of the same three test strains were then obtained through time series experiments over periods of 30min.
Project description:Trancriptional response of pediocin exposure of V583 and V583 expressing immunity (petAIM), and the transcriptional response of petAIM compared to both V583 and V583 containing the vector pet.
Project description:The transcriptional responses of class IIa bacteriocin resistance in 4 mutants of Enterococcus faecalis V583; three spontaneous pediocin PA-1 mutants; MOP1, MOP2 and MOP5 and one delta-mptD mutant called MOM1, studied by microarrays in E. faecalis V583.
Project description:ICP-MS analysis of Streptococcus pneumoniae D39 reveals a high cell-associated manganese (Mn(II)) concentration that is comparable to that of zinc (Zn(II)). Stressing these cells with 100-200 µM Zn(II) leads to a slow-growth phenotype and a reduction in total Mn(II) concentration, with no decrease in the concentrations of other metal ions. Supplementation of the growth media with as little as 10 µM Mn(II) fully restores wildtype growth patterns and normal levels of cell-associated Mn(II). DNA microarray analysis reveals that zinc stress induces the expected upregulation of czcD (encoding a zinc effluxer), but also a pleiotropic transcriptional response suggestive of mild cell wall stress. Genes encoding a nitric oxide detoxification system (nmlR) and the Mn(II) uptake system (psaABC) are also induced. We conclude that Zn(II) toxicity results in a cytoplasmic Mn(II) deficiency, possibly caused by competition at the Mn(II) uptake transporter protein PsaA. Bacteria were grown statically in Brain Heart Infusion media (Bacto BHI, Becton Dickinson) or BHI supplemented with metals at 37C in an atmosphere of 5% CO2 to a culture density of OD620~0.2 and were processed as described in the related Sample records. Samples were collected from three independent biological replicates, including one dye swap. Data were analyzed using software from the TM4 Microarray Software Suite (www.tm4.org). GenePix results files (.gpr) were converted to TIGR MultiExperiment Viewer file format (.mev) using ExpressConverter 2.1 software and median spot intensities. Lowess (block) normalization was performed on non-background subtracted data using TIGR MIDAS 2.21 software. Spots flagged as bad (A=0 non-saturated pixels in spot; X= low spot intensity relative to background) were removed from the analysis. The cut-off for statistical significance of differential expression was set at Bayesian P =0.001 and an average up or down fold change of at least 1.8 fold. The data were normalized both with and without removal of flagged spots and used to calculate expression ratios and Bayesian P values. Ratios and P values did not differ significantly with or without removal of flagged spots.