keyword
MENU ▼
Read by QxMD icon Read
search

stress response membrane bacteria

keyword
https://www.readbyqxmd.com/read/27891500/interspecies-communication-between-pathogens-and-immune-cells-via-bacterial-membrane-vesicles
#1
Katerina S Jurkoshek, Ying Wang, Jaffre J Athman, Marian R Barton, Pamela A Wearsch
The production of extracellular vesicles is a universal mechanism for intercellular communication that is conserved across kingdoms. Prokaryotes secrete 50-250 nm membrane vesicles (MVs) in a manner that is regulated by environmental stress and is thought to promote survival. Since many types of host-derived stress are encountered during infection, this implies an important role for MV secretion in bacterial pathogenesis. Accordingly, MVs produced by gram-positive and gram-negative pathogens contain toxins, virulence factors, and other molecules that promote survival in the host...
2016: Frontiers in Cell and Developmental Biology
https://www.readbyqxmd.com/read/27878107/imaging-the-nadh-nad-homeostasis-for-understanding-the-metabolic-response-of-mycobacterium-to-physiologically-relevant-stresses
#2
Shabir A Bhat, Iram K Iqbal, Ashwani Kumar
The NADH:NAD(+) ratio is the primary indicator of the metabolic state of bacteria. NAD(H) homeostasis is critical for Mycobacterium tuberculosis (Mtb) survival and is thus considered an important drug target, but the spatio-temporal measurements of NAD(H) remain a challenge. Genetically encoded fluorescent biosensors of the NADH:NAD(+) ratios were recently described, paving the way for investigations of the metabolic state of pathogens during infection. Here we have adapted the genetically encoded biosensor Peredox for measurement of the metabolic state of Mtb in vitro and during infection of macrophage cells...
2016: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/27875752/toxicity-evaluation-of-e-juice-and-its-soluble-aerosols-generated-by-electronic-cigarettes-using-recombinant-bioluminescent-bacteria-responsive-to-specific-cellular-damages
#3
Shiv Bharadwaj, Robert J Mitchell, Anjum Qureshi, Javed H Niazi
Electronic-cigarettes (e-cigarette) are widely used as an alternative to traditional cigarettes but their safety is not well established. Herein, we demonstrate and validate an analytical method to discriminate the deleterious effects of e-cigarette refills (e-juice) and soluble e-juice aerosol (SEA) by employing stress-specific bioluminescent recombinant bacterial cells (RBCs) as whole-cell biosensors. These RBCs carry luxCDABE-operon tightly controlled by promoters that specifically induced to DNA damage (recA), superoxide radicals (sodA), heavy metals (copA) and membrane damage (oprF)...
November 12, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27875634/the-stringent-response-plays-a-key-role-in-bacillus-subtilis-survival-of-fatty-acid-starvation
#4
A A Pulschen, D E Sastre, F Machinandiarena, A Crotta Asis, D Albanesi, D de Mendoza, F J Gueiros-Filho
The stringent response is a universal adaptive mechanism to protect bacteria from nutritional and environmental stresses. The role of the stringent response during lipid starvation has been studied only in Gram-negative bacteria. Here we report that the stringent response also plays a crucial role in the adaptation of the model Gram-positive Bacillus subtilis to fatty acid starvation. B. subtilis lacking all three (p)ppGpp-synthetases (RelBs , RelP and RelQ) or bearing a RelBs variant that no longer synthesizes (p)ppGpp suffer extreme loss of viability upon lipid starvation...
November 22, 2016: Molecular Microbiology
https://www.readbyqxmd.com/read/27873257/bacterial-histidine-kinases-overexpression-purification-and-inhibitor-screen
#5
Mike Gajdiss, Michael Türck, Gabriele Bierbaum
Bacterial histidine kinases are promising targets for new antimicrobial agents. In antibacterial therapy such agents could inhibit bacterial growth by targeting essential two-component regulatory systems or resensitize bacteria to known antibiotics by blocking stress responses like the cell wall stress response. However, (1) activity assays using the truncated phosphorylation domains have been shown to produce artifacts and (2) the purification of the full-length histidine kinases is complicated. Here, we describe a standard protocol for the recombinant expression and purification of functional full-length histidine kinases and other membrane proteins from gram-positive bacteria that do not harbor more than two trans-membrane domains using an Escherichia coli host...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/27865622/protecting-from-envelope-stress-variations-on-the-phage-shock-protein-theme
#6
REVIEW
Riccardo Manganelli, Maria Laura Gennaro
During envelope stress, critical inner-membrane functions are preserved by the phage-shock-protein (Psp) system, a stress response that emerged from work with Escherichia coli and other Gram-negative bacteria. Reciprocal regulatory interactions and multiple effector functions are well documented in these organisms. Searches for the Psp system across phyla reveal conservation of only one protein, PspA. However, examination of Firmicutes and Actinobacteria reveals that PspA orthologs associate with non-orthologous regulatory and effector proteins retaining functions similar to those in Gram-negative counterparts...
November 16, 2016: Trends in Microbiology
https://www.readbyqxmd.com/read/27834680/new-insights-into-the-cyclic-di-adenosine-monophosphate-c-di-amp-degradation-pathway-and-the-requirement-of-the-cyclic-dinucleotide-for-acid-stress-resistance-in-staphylococcus-aureus
#7
Lisa Bowman, Merve S Zeden, Christopher F Schuster, Volkhard Kaever, Angelika Grundling
Nucleotide signaling networks are key to facilitate alterations in gene expression, protein function and enzyme activity in response to diverse stimuli. Cyclic di-adenosine monophosphate (c-di-AMP) is an important secondary messenger molecule produced by the human pathogen Staphylococcus aureus and is involved in regulating a number of physiological processes including potassium transport. S. aureus must ensure tight control over its cellular levels as both high levels of the dinucleotide and its absence result in a number of detrimental phenotypes...
November 10, 2016: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/27821607/novel-rpos-dependent-mechanisms-strengthen-the-envelope-permeability-barrier-during-stationary-phase
#8
Angela M Mitchell, Wei Wang, Thomas J Silhavy
: Gram-negative bacteria have effective methods of excluding toxic compounds including a largely impermeable outer membrane (OM) and a range of efflux pumps. Furthermore, when cells become nutrient-limited, RpoS enacts a global expression change providing cross-protection against many stresses. Here, we utilized sensitivity to an anionic detergent (sodium dodecyl sulfate, SDS) to model probe changes occurring to the cell's permeability barrier during nutrient limitation. Escherichia coli is resistant to SDS whether cells are actively growing, carbon-limited, or nitrogen-limited...
November 7, 2016: Journal of Bacteriology
https://www.readbyqxmd.com/read/27816003/cadmium-tolerant-characteristic-of-a-newly-isolated-lactococcus-lactis-subsp-lactis
#9
Yao Sheng, Ying Wang, Xuan Yang, Boyang Zhang, Xiaoyun He, Wentao Xu, Kunlun Huang
Environmental contamination caused by heavy metals poses a major threat to the wildlife and human health for their toxicity and intrinsically persistent nature. Some specific food grade bacteria have properties that enable them to eliminate heavy metals from food and water. Lactococcus lactis subsp. lactis, newly isolated from pickles, is a cadmium (Cd) tolerant bacteria. Cd resistant properties of the lactis was evaluated under different Cd stresses. Cd accumulation in different cellular parts was determined by ICP-MS and cell morphology changes were measured by SEM-EDS and TEM-EDS...
December 2016: Environmental Toxicology and Pharmacology
https://www.readbyqxmd.com/read/27812150/the-genome-of-the-toluene-degrading-pseudomonas-veronii-strain-1ydbtex2-and-its-differential-gene-expression-in-contaminated-sand
#10
Marian Morales, Vladimir Sentchilo, Claire Bertelli, Andrea Komljenovic, Nadezda Kryuchkova-Mostacci, Audrey Bourdilloud, Burkhard Linke, Alexander Goesmann, Keith Harshman, Francisca Segers, Fabien Delapierre, Damien Fiorucci, Mathieu Seppey, Evgeniya Trofimenco, Pauline Berra, Athimed El Taher, Chloé Loiseau, Dejan Roggero, Madeleine Sulfiotti, Angela Etienne, Gustavo Ruiz Buendia, Loïc Pillard, Angelique Escoriza, Roxane Moritz, Cedric Schneider, Esteban Alfonso, Fatma Ben Jeddou, Oliver Selmoni, Gregory Resch, Gilbert Greub, Olivier Emery, Manupriyam Dubey, Trestan Pillonel, Marc Robinson-Rechavi, Jan Roelof van der Meer
The natural restoration of soils polluted by aromatic hydrocarbons such as benzene, toluene, ethylbenzene and m- and p-xylene (BTEX) may be accelerated by inoculation of specific biodegraders (bioaugmentation). Bioaugmentation mainly involves introducing bacteria that deploy their metabolic properties and adaptation potential to survive and propagate in the contaminated environment by degrading the pollutant. In order to better understand the adaptive response of cells during a transition to contaminated material, we analyzed here the genome and short-term (1 h) changes in genome-wide gene expression of the BTEX-degrading bacterium Pseudomonas veronii 1YdBTEX2 in non-sterile soil and liquid medium, both in presence or absence of toluene...
2016: PloS One
https://www.readbyqxmd.com/read/27801293/the-polymyxin-b-induced-transcriptomic-response-of-a-clinical-multidrug-resistant-klebsiella-pneumoniae-involves-multiple-regulatory-elements-and-intracellular-targets
#11
Pablo Ivan Pereira Ramos, Márlon Grégori Flores Custódio, Guadalupe Del Rosario Quispe Saji, Thiago Cardoso, Gisele Lucchetti da Silva, Graziela Braun, Willames M B S Martins, Raquel Girardello, Ana Tereza Ribeiro de Vasconcelos, Elmer Fernández, Ana Cristina Gales, Marisa Fabiana Nicolás
BACKGROUND: The emergence of multidrug-resistant Klebsiella pneumoniae is a major public health concern. Many K. pneumoniae infections can only be treated when resorting to last-line drugs such as polymyxin B (PB). However, resistance to this antibiotic is also observed, although insufficient information is described on its mode of action as well as the mechanisms used by resistant bacteria to evade its effects. We aimed to study PB resistance and the influence of abiotic stresses in a clinical K...
October 25, 2016: BMC Genomics
https://www.readbyqxmd.com/read/27796440/biophysical-characterization-of-the-lactobacillus-delbrueckii-subsp-bulgaricus-membrane-during-cold-and-osmotic-stress-and-its-relevance-for-cryopreservation
#12
Julie Meneghel, Stéphanie Passot, Sébastien Dupont, Fernanda Fonseca
Freezing lactic acid bacteria often leads to cell death and loss of technological properties. Our objective was to provide an in-depth characterization of the biophysical properties of the Lactobacillus delbrueckii subsp. bulgaricus membrane in relation to its freeze resistance. Freezing was represented as a combination of cold and osmotic stress. This work investigated the relative incidence of increasing sucrose concentrations coupled or not with subzero temperatures without ice nucleation on the biological and biophysical responses of two strains with different membrane fatty acid compositions and freeze resistances...
October 31, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27790614/antimicrobial-activity-of-cationic-antimicrobial-peptides-against-gram-positives-current-progress-made-in-understanding-the-mode-of-action-and-the-response-of-bacteria
#13
REVIEW
Soraya Omardien, Stanley Brul, Sebastian A J Zaat
Antimicrobial peptides (AMPs) have been proposed as a novel class of antimicrobials that could aid the fight against antibiotic resistant bacteria. The mode of action of AMPs as acting on the bacterial cytoplasmic membrane has often been presented as an enigma and there are doubts whether the membrane is the sole target of AMPs. Progress has been made in clarifying the possible targets of these peptides, which is reported in this review with as focus gram-positive vegetative cells and spores. Numerical estimates are discussed to evaluate the possibility that targets, other than the membrane, could play a role in susceptibility to AMPs...
2016: Frontiers in Cell and Developmental Biology
https://www.readbyqxmd.com/read/27782347/natural-product-inspired-aminoepoxybenzoquinones-kill-members-of-the-gram-negative-pathogen-salmonella-by-attenuating-cellular-stress-response
#14
Franziska A Mandl, Volker C Kirsch, Ilke Ugur, Elena Kunold, Jan Vomacka, Christian Fetzer, Sabine Schneider, Klaus Richter, Thilo M Fuchs, Iris Antes, Stephan A Sieber
Gram-negative bacteria represent a challenging task for antibacterial drug discovery owing to their impermeable cell membrane and restricted uptake of small molecules. We herein describe the synthesis of natural-product-derived epoxycyclohexenones and explore their antibiotic activity against several pathogenic bacteria. A compound with activity against Salmonella Typhimurium was identified, and the target enzymes were unraveled by quantitative chemical proteomics. Importantly, two protein hits were linked to bacterial stress response, and corresponding assays revealed an elevated susceptibility to reactive oxygen species upon compound treatment...
November 14, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27771745/stress-responses-of-acinetobacter-strain-y-during-phenol-degradation
#15
Johnson Lin
Quantification of gene expression of Acinetobacter strain Y under 1000 mg/l of phenol was investigated using qPCR and proteomic analyses. The results show that Acinetobacter strain Y utilized 100 % of phenol within 18 h of exposure. The results of qPCR and proteomic analyses demonstrate a sequential expression of phenol-degrading genes of Acinetobacter strain Y via the ortho-pathway followed by the β-ketoadipate pathway. Many stress-responsive proteins such as chaperones, chaperonins, porins and the enzymes involved in the signal transduction pathway were upregulated especially in the early stage...
October 22, 2016: Archives of Microbiology
https://www.readbyqxmd.com/read/27731373/toxicity-of-zno-and-tio2-to-escherichia-coli-cells
#16
Yu Hang Leung, Xiaoying Xu, Angel P Y Ma, Fangzhou Liu, Alan M C Ng, Zhiyong Shen, Lee A Gethings, Mu Yao Guo, Aleksandra B Djurišić, Patrick K H Lee, Hung Kay Lee, Wai Kin Chan, Frederick C C Leung
We performed a comprehensive investigation of the toxicity of ZnO and TiO2 nanoparticles using Escherichia coli as a model organism. Both materials are wide band gap n-type semiconductors and they can interact with lipopolysaccharide molecules present in the outer membrane of E. coli, as well as produce reactive oxygen species (ROS) under UV illumination. Despite the similarities in their properties, the response of the bacteria to the two nanomaterials was fundamentally different. When the ROS generation is observed, the toxicity of nanomaterial is commonly attributed to oxidative stress and cell membrane damage caused by lipid peroxidation...
October 12, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27720009/the-journey-of-lipoproteins-through-the-cell-one-birthplace-multiple-destinations
#17
J Szewczyk, J-F Collet
Bacterial lipoproteins are a very diverse group of proteins characterized by the presence of an N-terminal lipid moiety that serves as a membrane anchor. Lipoproteins have a wide variety of crucial functions, ranging from envelope biogenesis to stress response. In Gram-negative bacteria, lipoproteins can be targeted to various destinations in the cell, including the periplasmic side of the cytoplasmic or outer membrane, the cell surface or the external milieu. The sorting mechanisms have been studied in detail in Escherichia coli, but exceptions to the rules established in this model bacterium exist in other bacteria...
2016: Advances in Microbial Physiology
https://www.readbyqxmd.com/read/27698088/interactions-between-the-cytoplasmic-domains-of-pspb-and-pspc-silence-the-yersinia-enterocolitica-phage-shock-protein-response
#18
Josué Flores-Kim, Andrew J Darwin
: The phage shock protein (Psp) system is a widely conserved cell envelope stress response that is essential for the virulence of some bacteria, including Yersinia enterocolitica Recruitment of PspA by the inner membrane PspB-PspC complex characterizes the activated state of this response. The PspB-PspC complex has been proposed to be a stress-responsive switch, changing from an OFF to an ON state in response to an inducing stimulus. In the OFF state, PspA cannot access its binding site in the C-terminal cytoplasmic domain of PspC (PspC(CT)), because this site is bound to PspB...
December 15, 2016: Journal of Bacteriology
https://www.readbyqxmd.com/read/27698081/the-small-rna-gcvb-promotes-mutagenic-break-repair-by-opposing-the-membrane-stress-response
#19
Brittany Barreto, Elizabeth Rogers, Jun Xia, Ryan L Frisch, Megan Richters, Devon M Fitzgerald, Susan M Rosenberg
: Microbes and human cells possess mechanisms of mutagenesis activated by stress responses. Stress-inducible mutagenesis mechanisms may provide important models for mutagenesis that drives host-pathogen interactions, antibiotic resistance, and possibly much of evolution generally. In Escherichia coli, repair of DNA double-strand breaks is switched to a mutagenic mode, using error-prone DNA polymerases, via the SOS DNA damage and general (σ(S)) stress responses. We investigated small RNA (sRNA) clients of Hfq, an RNA chaperone that promotes mutagenic break repair (MBR), and found that GcvB promotes MBR by allowing a robust σ(S) response, achieved via opposing the membrane stress (σ(E)) response...
December 15, 2016: Journal of Bacteriology
https://www.readbyqxmd.com/read/27665456/genomic-and-transcriptome-analysis-of-triclosan-response-of-a-multidrug-resistant-acinetobacter-baumannii-strain-mdr-zj06
#20
Borui Pi, Dongliang Yu, Xiaoting Hua, Zhi Ruan, Yunsong Yu
During the last decade, an increasing amount of attention has focused on the potential threat of triclosan to both the human body and environmental ecology. However, the role of triclosan in the development of drug resistance and cross resistance is still in dispute ascribed to largely unknown of triclosan resistance mechanism. In this work, Acinetobacter baumannii MDR-ZJ06, a multidrug-resistant strain, was induced by triclosan, and the genomic variation and transcriptional levels were investigated, respectively...
September 24, 2016: Archives of Microbiology
keyword
keyword
109914
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"