keyword
MENU ▼
Read by QxMD icon Read
search

Bacterial toxin

keyword
https://www.readbyqxmd.com/read/28106083/the-association-of-bacterial-c9-based-ttx-like-compounds-with-prorocentrum-minimum-opens-new-uncertainties-about-shellfish-seafood-safety
#1
Inés Rodríguez, Amparo Alfonso, Eva Alonso, Juan A Rubiolo, María Roel, Aristidis Vlamis, Panagiota Katikou, Stephen A Jackson, Margassery Lekha Menon, Alan Dobson, Luis M Botana
In 2012, Tetrodotoxin (TTX) was identified in mussels and linked to the presence of Prorocentrum minimum (P. minimum) in Greece. The connexion between TTX and P. minimum was further studied in this paper. First, the presence of TTX-producer bacteria, Vibrio and Pseudomonas spp, was confirmed in Greek mussels. In addition these samples showed high activity as inhibitors of sodium currents (INa). P. minimum was before associated with neurotoxic symptoms, however, the nature and structure of toxins produced by this dinoflagellate remains unknown...
January 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28106081/shigatoxin-encoding-bacteriophage-%C3%AF-24b-modulates-bacterial-metabolism-to-raise-antimicrobial-tolerance
#2
G S Holt, J K Lodge, A J McCarthy, A K Graham, G Young, S H Bridge, A K Brown, M Veses-Garcia, C V Lanyon, A Sails, H E Allison, D L Smith
How temperate bacteriophages play a role in microbial infection and disease progression is not fully understood. They do this in part by carrying genes that promote positive evolutionary selection for the lysogen. Using Biolog phenotype microarrays and comparative metabolite profiling we demonstrate the impact of the well-characterised Shiga toxin-prophage ϕ24B on its Escherichia coli host MC1061. As a lysogen, the prophage alters the bacterial physiology by increasing the rates of respiration and cell proliferation...
January 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28104376/lipidomic-profile-of-gm95-cell-death-induced-by-clostridium-perfringens-alpha-toxin
#3
Marco M Manni, Juan G Valero, Miriam Pérez-Cormenzana, Ainara Cano, Cristina Alonso, Félix M Goñi
Clostridium perfringens alpha-toxin (ATX) is considered as a prototype of cytotoxic bacterial phospholipases C, and is the major virulence factor in C. perfringens-induced gas gangrene. It is known that, depending on the dose, ATX causes membrane disruption and cytolysis or only limited hydrolysis of its substrates. In the latter case, toxin activity leads to the unregulated generation of bioactive lipids that can ultimately induce cell death. We have characterized apoptosis and necrosis in highly ATX-sensitive, ganglioside-deficient cells exposed to different concentrations of ATX and we have studied the lipidomic profile of cells treated with ATX as compared to native cells to detect the main changes in the lipidomic profile and the possible involvement of lipid signals in cell death...
January 16, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/28098783/the-influence-of-the-toxin-antitoxin-mazef-on-growth-and-survival-of-listeria-monocytogenes-under-stress
#4
Thomas D Curtis, Ippei Takeuchi, Lone Gram, Gitte M Knudsen
A major factor in the resilience of Listeria monocytogenes is the alternative sigma factor B (σ(B)). Type II Toxin/Antitoxin (TA) systems are also known to have a role in the bacterial stress response upon activation via the ClpP or Lon proteases. Directly upstream of the σ(B) operon in L. monocytogenes is the TA system mazEF, which can cleave mRNA at UACMU sites. In this study, we showed that the mazEF TA locus does not affect the level of persister formation during treatment with antibiotics in lethal doses, but exerts different effects according to the sub-inhibitory stress added...
January 13, 2017: Toxins
https://www.readbyqxmd.com/read/28098781/distinct-neurotoxicity-profile-of-listeriolysin-o-from-listeria-monocytogenes
#5
Jana Maurer, Sabrina Hupp, Carolin Bischoff, Christina Foertsch, Timothy J Mitchell, Trinad Chakraborty, Asparouh I Iliev
Cholesterol-dependent cytolysins (CDCs) are protein toxins that originate from Gram-positive bacteria and contribute substantially to their pathogenicity. CDCs bind membrane cholesterol and build prepores and lytic pores. Some effects of the toxins are observed in non-lytic concentrations. Two pathogens, Streptococcus pneumoniae and Listeria monocytogenes, cause fatal bacterial meningitis, and both produce toxins of the CDC family-pneumolysin and listeriolysin O, respectively. It has been demonstrated that pneumolysin produces dendritic varicosities (dendrite swellings) and dendritic spine collapse in the mouse neocortex, followed by synaptic loss and astrocyte cell shape remodeling without elevated cell death...
January 13, 2017: Toxins
https://www.readbyqxmd.com/read/28095880/high-throughput-expression-of-animal-venom-toxins-in-escherichia-coli-to-generate-a-large-library-of-oxidized-disulphide-reticulated-peptides-for-drug-discovery
#6
Jeremy Turchetto, Ana Filipa Sequeira, Laurie Ramond, Fanny Peysson, Joana L A Brás, Natalie J Saez, Yoan Duhoo, Marilyne Blémont, Catarina I P D Guerreiro, Loic Quinton, Edwin De Pauw, Nicolas Gilles, Hervé Darbon, Carlos M G A Fontes, Renaud Vincentelli
BACKGROUND: Animal venoms are complex molecular cocktails containing a wide range of biologically active disulphide-reticulated peptides that target, with high selectivity and efficacy, a variety of membrane receptors. Disulphide-reticulated peptides have evolved to display improved specificity, low immunogenicity and to show much higher resistance to degradation than linear peptides. These properties make venom peptides attractive candidates for drug development. However, recombinant expression of reticulated peptides containing disulphide bonds is challenging, especially when associated with the production of large libraries of bioactive molecules for drug screening...
January 17, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28094982/bacterial-genome-editing-via-a-designed-toxin-antitoxin-cassette
#7
Jie Wu, Aihua Deng, Qinyun Sun, Hua Bai, Zhaopeng Sun, Xiuling Shang, Yun Zhang, Qian Liu, Yong Liang, Shuwen Liu, Yongsheng Che, Tingyi Wen
Manipulating the bacterial genomes in an efficient manner is essential to biological and biotechnological research. Despite usage of various modules for genomic editing with counter-selectable markers including the toxin genes, an easy-to-use and highly designable toxin-antitoxin (TA) cassette without causing any leakages is urgently needed for efficient genome editing of the Gram-positive bacteria. Here, we reprogramed the bacterial TA systems as a toxin counter-selectable cassette regulated by an antitoxin switch (TCCRAS) for genetic modifications in the extensively studied and utilized Gram-positive bacteria, B...
January 17, 2017: ACS Synthetic Biology
https://www.readbyqxmd.com/read/28092360/chemical-proteomics-reveals-adp-ribosylation-of-small-gtpases-during-oxidative-stress
#8
Nathan P Westcott, Joseph P Fernandez, Henrik Molina, Howard C Hang
ADP-ribosylation is a post-translational modification that is known to be involved in cellular homeostasis and stress but has been challenging to analyze biochemically. To facilitate the detection of ADP-ribosylated proteins, we show that an alkyne-adenosine analog, N(6)-propargyl adenosine (N(6)pA), is metabolically incorporated in mammalian cells and enables fluorescence detection and proteomic analysis of ADP-ribosylated proteins. Notably, our analysis of N(6)pA-labeled proteins that are upregulated by oxidative stress revealed differential ADP-ribosylation of small GTPases...
January 16, 2017: Nature Chemical Biology
https://www.readbyqxmd.com/read/28088062/a-retrospective-audit-of-bacterial-culture-results-of-donated-human-milk-in-perth-western-australia
#9
Yahya Almutawif, Benjamin Hartmann, Megan Lloyd, Wendy Erber, Donna Geddes
INTRODUCTION: The bacterial content of donated human milk is either endogenous or introduced via contamination. Defining milk bank bacterial content will allow researchers to devise appropriate tests for significant and commonly encountered organisms. OBJECTIVE: A retrospective audit was conducted on data recorded from the Perron Rotary Express Milk Bank, King Edward Memorial Hospital, Subiaco, Western Australia. This aimed to describe the incidence of bacterial species detected in donated human milk and to identify potentially pathogenic bacteria...
January 11, 2017: Early Human Development
https://www.readbyqxmd.com/read/28087406/erythrocyte-membrane-coated-nanogel-for-combinatorial-antivirulence-and-responsive-antimicrobial-delivery-against-staphylococcus-aureus-infection
#10
Yue Zhang, Jianhua Zhang, Wangsong Chen, Pavimol Angsantikul, Kevin A Spiekermann, Ronnie H Fang, Weiwei Gao, Liangfang Zhang
We reported an erythrocyte membrane-coated nanogel (RBC-nanogel) system with combinatorial antivirulence and responsive antibiotic delivery for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection. RBC membrane was coated onto the nanogel via a membrane vesicle templated in situ gelation process, whereas the redox-responsiveness was achieved by using a disulfide bond-based crosslinker. We demonstrated that the RBC-nanogels effectively neutralized MRSA-associated toxins in extracellular environment and the toxin neutralization in turn promoted bacterial uptake by macrophages...
January 10, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28081446/host-to-host-transmission-of-streptococcus-pneumoniae-is-driven-by-its-inflammatory-toxin-pneumolysin
#11
M Ammar Zafar, Yang Wang, Shigeto Hamaguchi, Jeffrey N Weiser
Host-to-host transmission is a critical step for infection. Here we studied transmission of the opportunistic pathogen Streptococcus pneumoniae in an infant mouse model. Transmission from nasally colonized pups required high levels of bacterial shedding in nasal secretions and was temporally correlated with, and dependent upon, the acute inflammatory response. Pneumolysin, a pore-forming cytotoxin and major virulence determinant, was both necessary and sufficient to promote inflammation, which increased shedding and allowed for intralitter transmission...
January 11, 2017: Cell Host & Microbe
https://www.readbyqxmd.com/read/28081148/characterization-of-multi-drug-resistant-enterococcus-faecalis-isolated-from-cephalic-recording-chambers-in-research-macaques-macaca-spp
#12
Stephanie E Woods, Mia T Lieberman, Francois Lebreton, Elise Trowel, César de la Fuente-Núñez, Joanne Dzink-Fox, Michael S Gilmore, James G Fox
Nonhuman primates are commonly used for cognitive neuroscience research and often surgically implanted with cephalic recording chambers for electrophysiological recording. Aerobic bacterial cultures from 25 macaques identified 72 bacterial isolates, including 15 Enterococcus faecalis isolates. The E. faecalis isolates displayed multi-drug resistant phenotypes, with resistance to ciprofloxacin, enrofloxacin, trimethoprim-sulfamethoxazole, tetracycline, chloramphenicol, bacitracin, and erythromycin, as well as high-level aminoglycoside resistance...
2017: PloS One
https://www.readbyqxmd.com/read/28077560/mechanistic-insights-into-type-i-toxin-antitoxin-systems-in-helicobacter-pylori-the-importance-of-mrna-folding-in-controlling-toxin-expression
#13
Hélène Arnion, Dursun Nizam Korkut, Sara Masachis Gelo, Sandrine Chabas, Jérémy Reignier, Isabelle Iost, Fabien Darfeuille
Type I toxin-antitoxin (TA) systems have been identified in a wide range of bacterial genomes. Here, we report the characterization of a new type I TA system present on the chromosome of the major human gastric pathogen, Helicobacter pylori We show that the aapA1 gene encodes a 30 amino acid peptide whose artificial expression in H. pylori induces cell death. The synthesis of this toxin is prevented by the transcription of an antitoxin RNA, named IsoA1, expressed on the opposite strand of the toxin gene. We further reveal additional layers of post-transcriptional regulation that control toxin expression: (i) transcription of the aapA1 gene generates a full-length transcript whose folding impedes translation (ii) a 3' end processing of this message generates a shorter transcript that, after a structural rearrangement, becomes translatable (iii) but this rearrangement also leads to the formation of two stem-loop structures allowing formation of an extended duplex with IsoA1 via kissing-loop interactions...
January 10, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28074026/promyelocytic-leukemia-protein-pml-controls-listeria-monocytogenes-infection
#14
David Ribet, Valérie Lallemand-Breitenbach, Omar Ferhi, Marie-Anne Nahori, Hugo Varet, Hugues de Thé, Pascale Cossart
: The promyelocytic leukemia protein (PML) is the main organizer of stress-responsive subnuclear structures called PML nuclear bodies. These structures recruit multiple interactors and modulate their abundance or their posttranslational modifications, notably by the SUMO ubiquitin-like modifiers. The involvement of PML in antiviral responses is well established. In contrast, the role of PML in bacterial infection remains poorly characterized. Here, we show that PML restricts infection by the pathogenic bacterium Listeria monocytogenes but not by Salmonella enterica serovar Typhimurium...
January 10, 2017: MBio
https://www.readbyqxmd.com/read/28073540/phylogenetic-structure-of-bacterial-assemblages-co-occurring-with-ostreopsis-cf-ovata-bloom
#15
Silvana Vanucci, Flavio Guidi, Rossella Pistocchi, Richard A Long
Extensive blooms of the toxic epiphytic/benthic dinoflagellate Ostreopsis cf. ovata are being reported with increasing frequency and spatial distribution in temperate coastal regions including the Mediterranean. These blooms are of human and environmental health concern due to the production of isobaric palytoxin and a wide range of ovatoxins by Ostreopsis cf. ovata. Bacterial-microalgal interactions are important regulators in algal bloom dynamics and potentially toxin dynamics. This study investigated the bacterial assemblages co-occurring with O...
May 2016: Harmful Algae
https://www.readbyqxmd.com/read/28073480/a-review-of-the-global-ecology-genomics-and-biogeography-of-the-toxic-cyanobacterium-microcystis-spp
#16
REVIEW
Matthew J Harke, Morgan M Steffen, Christopher J Gobler, Timothy G Otten, Steven W Wilhelm, Susanna A Wood, Hans W Paerl
This review summarizes the present state of knowledge regarding the toxic, bloom-forming cyanobacterium, Microcystis, with a specific focus on its geographic distribution, toxins, genomics, phylogeny, and ecology. A global analysis found documentation suggesting geographic expansion of Microcystis, with recorded blooms in at least 108 countries, 79 of which have also reported the hepatatoxin microcystin. The production of microcystins (originally "Fast-Death Factor") by Microcystis and factors that control synthesis of this toxin are reviewed, as well as the putative ecophysiological roles of this metabolite...
April 2016: Harmful Algae
https://www.readbyqxmd.com/read/28073457/production-of-bmaa-and-dab-by-diatoms-phaeodactylum-tricornutum-chaetoceros-sp-chaetoceros-calcitrans-and-thalassiosira-pseudonana-and-bacteria-isolated-from-a-diatom-culture
#17
Damien Réveillon, Véronique Séchet, Philipp Hess, Zouher Amzil
Microalgae have previously been reported to contain β-N-methylamino-l-alanine (BMAA), and the global presence of these primary producers has been associated with the widespread occurrence of BMAA in marine organisms. It has been repeatedly shown that filter-feeding bivalves accumulate phytoplankton species and their toxins. In this study, the concentrations of total soluble BMAA and DAB as a function of growth phase were observed for four non-axenic diatom species (i.e. Phaeodactylum tricornutum, Chaetoceros sp...
September 2016: Harmful Algae
https://www.readbyqxmd.com/read/28069812/cooperative-substrate-cofactor-interactions-and-membrane-localization-of-the-bacterial-pla2-enzyme-exou
#18
Maxx H Tessmer, David M Anderson, Adam Buchaklian, Dara W Frank, Jimmy B Feix
The ExoU type III secretion enzyme is a potent phospholipase A2 secreted by the Gram-negative opportunistic pathogen, Pseudomonas aeruginosa. Activation of phospholipase activity is induced by protein-protein interactions with ubiquitin in the cytosol of a targeted eukaryotic cell, leading to destruction of host cell membranes. Previous work in our laboratory suggested that conformational changes within a C-terminal domain of the toxin might be involved in the activation mechanism. In this study, we use site-directed spin labeling electron paramagnetic resonance spectroscopy to investigate conformational changes in a C-terminal four-helical bundle region of ExoU as it interacts with lipid substrates and ubiquitin, and to examine the localization of this domain with respect to the lipid bilayer...
January 9, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28069396/multi-level-evaluation-of-escherichia-coli-polyphosphate-related-mutants-using-global-transcriptomic-proteomic-and-phenomic-analyses
#19
Macarena Varas, Camilo Valdivieso, Cecilia Mauriaca, Javiera Ortíz-Severín, Alberto Paradela, Ignacio Poblete-Castro, Ricardo Cabrera, Francisco P Chávez
BACKGROUND: Polyphosphate (polyP) is a linear biopolymer found in all living cells. In bacteria, mutants lacking polyphosphate kinase 1 (PPK1), the enzyme responsible for synthesis of most polyP, have many structural and functional defects. However, little is known about the causes of these pleiotropic alterations. The link between ppk1 deletion and those numerous phenotypes observed can be the result of complex molecular interactions that can be elucidated via a systems biology approach...
January 6, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28065740/bacterial-signaling-to-the-nervous-system-via-toxins-and-metabolites
#20
REVIEW
Nicole J Yang, Isaac M Chiu
Mammalian hosts interface intimately with commensal and pathogenic bacteria. It is increasingly clear that molecular interactions between the nervous system and microbes contribute to health and disease. Both commensal and pathogenic bacteria are capable of producing molecules that act on neurons and affect essential aspects of host physiology. Here we highlight several classes of physiologically important molecular interactions that occur between bacteria and the nervous system. First, clostridial neurotoxins block neurotransmission to or from neurons by targeting the SNARE complex, causing the characteristic paralyses of botulism and tetanus during bacterial infection...
January 5, 2017: Journal of Molecular Biology
keyword
keyword
64309
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"