New Brucella species
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB52673 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We describe the isolation of sufficient Brucella abortus RNA from primary host cell environment using modified reported methods for RNA-seq analysis, and simultaneously characterize the transcriptional profiles of intracellular B. abortus and bone marrow-derived macrophages (BMM) from BALB/c mice at 24 h (replicative phase) post-infection.
2017-07-08 | GSE100914 | GEO
Project description:In this study we report that B. melitensis at the late logarithmic phase of growth are more invasive for HeLa cells than at mid logarithmic or stationary growth phases. Microarray analysis of B. melitensis gene expression identified 414 up- and 40 down-regulated genes in late-log growth phase compared to the stationary growth phase. The vast majority of the up-regulated genes in late-log cultures were those associated with DNA replication, transcription and translation, intermediate metabolism, energy production and conversion, membrane transport and cell envelope, biogenesis and outer membrane, while the down-regulated genes were distributed among several functional categories. This first Brucella global gene expression study provides novel information on growth phase-specific gene regulation important not only for understanding Brucella physiology but also the initial molecular interactions between Brucella and its host. Keywords: Comparison bacterial growth phase normalized to genomic DNA There are two kind of samples consisting of RNA isolated from Brucella melitensis grown logarithmically or at stationary phase. There are four biological replicates of each sample. Every Brucella melitensis open reading frame was printed in triplicate on each microarray, thereby providing three technical replicates for each biological replicates. Each replicate was normalized against labeled Brucella melitensis genomic DNA.
2010-05-19 | E-GEOD-11192 | biostudies-arrayexpress
Project description:Brucella dynamically engage macrophages while trafficking to an intracellular replicative niche as macrophages, the first line of innate host defense, attempt to eliminate organisms. Brucella melitensis, B. neotomae, and B. ovis are highly homologous, yet exhibit a range of host pathogenicity and specificity. RAW 264.7 macrophages infected with B. melitensis, and B. ovis exhibit divergent patterns of bacterial persistence and clearance; conversely, B. melitensis and B. neotomae exhibit similar patterns of infection. Evaluating early macrophage interaction with Brucella spp. allows discovery of host entry and intracellular translocation mechanisms, rather than bacterial replication. Microarray analysis of macrophage transcript levels following a 4 hr Brucella spp. infection revealed 130 probe sets altered compared to uninfected macrophages; specifically, 72 probe sets were increased and 58 probe sets were decreased with any Brucella spp. Interestingly, much of the inflammatory response was not regulated by the number of Brucella gaining intracellular entry, as macrophage transcript levels were often equivalent among B. melitensis, B. ovis, and B. neotomae infections. An additional 33 probe sets were identified with altered macrophage transcript levels among Brucella spp. infections that may correlate with species specific host defenses and intracellular survival. Gene ontological categorization unveiled genes altered among species are involved in cell growth and maintenance, response to external stimuli, transcription regulation, transporter activity, endopeptidase inhibitor activity and G-protein mediated signaling. Host transcript profiles provide a foundation to understand variations in Brucella spp. infections, while structure of the macrophage response and intracellular niche of Brucella spp. will be revealed through piecewise consideration of host signaling pathways. Keywords: Macrophage, intracellular pathogen, Brucella melitensis, Brucella neotomae, Brucella ovis, inflammatory immune response, species specificity
2010-01-01 | GSE8385 | GEO
Project description:In this study we report that B. melitensis at the late logarithmic phase of growth are more invasive for HeLa cells than at mid logarithmic or stationary growth phases. Microarray analysis of B. melitensis gene expression identified 414 up- and 40 down-regulated genes in late-log growth phase compared to the stationary growth phase. The vast majority of the up-regulated genes in late-log cultures were those associated with DNA replication, transcription and translation, intermediate metabolism, energy production and conversion, membrane transport and cell envelope, biogenesis and outer membrane, while the down-regulated genes were distributed among several functional categories. This first Brucella global gene expression study provides novel information on growth phase-specific gene regulation important not only for understanding Brucella physiology but also the initial molecular interactions between Brucella and its host. Keywords: Comparison bacterial growth phase normalized to genomic DNA
2009-05-14 | GSE11192 | GEO
Project description:Using Solexa/Illumina's digital gene expression (DGE) system, a tag-based transcriptome sequencing method, we investigated the kinetic transcriptional profile of gene expression in macrophages infected with Brucella melitensis strain 16M. A key aspect of Brucella virulence is their ability to proliferate within professional and nonprofessional phagocytic host cells, thereby successfully bypassing the bactericidal effects of phagocytes. Their virulence and chronic infections are thought to be due to their ability to avoid the killing mechanisms within host cells. Defining the interaction between a host cell and Brucella is crucial to understanding the infectious process. Most researchers have studied the pathogens, but the host plays a very important role during infections. To date, relatively few host factors have been shown important in Brucella infections. However, little is known about the host networks that mediate infection. The objective of the study is to analyze the genes and cellular components related to the innate immunity response to determine the mechanisms through which Brucella avoids the host innate immunity. A total of 3576 and 3962 genes that are differentially expressed between 0 and 4 h and between 0 and 24 h were identified. The identified genes are related to immune processes, signal transduction, inflammation, apoptosis, cell membrane, transcriptional regulation, and intracellular trafficking. Our data have added to the current understanding of different host gene expressions during different infection phases by Brucella spp.
2014-03-25 | GSE28190 | GEO
Project description:Many pathogenic bacteria use a regulatory process termed Quorum Sensing (QS) to produce and detect small diffusible molecules to synchronize gene expression within a population. In Gram-negative bacteria, the detection and response to these molecules depend on transcriptional regulators belonging to the LuxR family. Such a system have been discovered in the intracellular pathogen Brucella melitensis, a Gram-negative bacteria responsible for brucellosis, a word-wide zoonosis remaining a serious public health concern in endemic countries. Two LuxR-type regulators, VjbR and BabR, have been identified in the genome of this pathogen. The vjbR mutant is highly attenuated in all tested models suggesting a crucial role of QS in the virulence of Brucella. This attenuation is at least due to the involvement of VjbR in the activation of the virB operon coding for a type four secretion system essential for Brucella to reach its intracellular replication compartment. At present, no function has been attributed to BabR. To assess the role of both Brucella QS-regulators, we performed in tandem comparative transcriptomic and proteomic analyses of vjbR and babR mutants. These experiments revealed that 10% of Brucella genome is regulated through those regulators, revealing that QS is a global regulatory system in this intracellular pathogen. The overlapping between BabR and VjbR targets suggest an unexpected cross-talk between these two regulators. Moreover, our results demonstrate that VjbR and BabR regulate many gene and/or proteins involved in stress response, metabolism and virulence. These targets are potentially involved in the adaptation of Brucella to the oxidative, pH and nutritional stresses encountered within the host. These findings highlight the involvement of QS in the virulence of Brucella and led us to suggest that this regulatory system could be implied in the spatial and sequential adaptation of Brucella to the host environment. Keywords: Quorum Sensing, Comparative gene expression, Brucella melitensis
2010-04-12 | GSE8844 | GEO
Project description:Brucella spp. is an intracellular pathogen in vivo. The intracellular B. melitensis transcriptome was determined by initially enriched and then amplified B. melitensis RNA from total RNA of B. melitensis-infected HeLa cells. Analysis of microarray results identified 161 and 115 genes differentially expressed at 4 and 12 h p.i., respectively. Most of the genes (78%) differentially expressed were down-regulated at the earliest time point, but up-regulated (75%) at 12 h p.i. The analysis of the results indicates that Brucella undergo an adaptation period during the first 4 h p.i. that is overcome by 12 h p.i., permitting Brucella to replicate intracellularly. Specific genes and biological processes identified in this study will further help elucidate how Brucella act during the early infectious process to their eventual benefit and to the detriment of the naïve host. Keywords: Time course study of intracellular B. melitensis gene expression
2012-12-27 | GSE14704 | GEO
Project description:In a time course study, we characterized global gene expression profile of B. melitensis-infected epithelium-like cells at the onset of infection. B. melitensis-infected HeLa cells exhibited a down-regulated expression profile at 4 h (48 up- and 109 down-regulated genes) that transitioned to an activated transcriptional profile at 12 h post-infection (733 up- and 224 down-regulated genes). The analysis of the results indicates that infected cells undergo an adaptation period during the first 4 h p.i. that is overcome by 12 h p.i., permitting Brucella to replicate intracellularly while minimally affecting host physiological processes. Specific genes and biological processes identified in this study will further help elucidate how both host and Brucella interact during the early infectious process to the eventual benefit of the pathogen and to the detriment of the naïve host. Keywords: Time course study of gene expression profile of Brucella melitensis-infected HeLa cells
2012-12-27 | GSE14703 | GEO
Project description:In a time course study, we characterized global gene expression profile of B. melitensis-infected epithelium-like cells at the onset of infection. B. melitensis-infected HeLa cells exhibited a down-regulated expression profile at 4 h (48 up- and 109 down-regulated genes) that transitioned to an activated transcriptional profile at 12 h post-infection (733 up- and 224 down-regulated genes). The analysis of the results indicates that infected cells undergo an adaptation period during the first 4 h p.i. that is overcome by 12 h p.i., permitting Brucella to replicate intracellularly while minimally affecting host physiological processes. Specific genes and biological processes identified in this study will further help elucidate how both host and Brucella interact during the early infectious process to the eventual benefit of the pathogen and to the detriment of the naM-CM-/ve host. Keywords: Time course study of gene expression profile of Brucella melitensis-infected HeLa cells We generated 4 different samples: A) RNA isolated from Brucella melitensis-infected HeLa cells at 4 h p.i.; B) RNA isolated from non-infected HeLa cells at 4 h p.i. of the A samples; C) RNA isolated from Brucella melitensis-infected HeLa cells at 12 h p.i., and D) RNA isolated from non-infected HeLa cells at 12 h p.i. of the D samples. The B. melitensis-infected HeLa cells gene expression was compared with gene expression from non-infected HeLa cells treated similarly. There are four biological replicates of each sample and time point (n=16). ORFs were single spotted on each microarray. Each replicate was normalized against labeled universal human reference RNA.
2012-12-27 | E-GEOD-14703 | biostudies-arrayexpress