keyword
MENU ▼
Read by QxMD icon Read
search

bacterial membrane

keyword
https://www.readbyqxmd.com/read/28727999/drug-ion-co-delivery-multi-functional-nanocarrier-to-regenerate-infected-tissue-defect
#1
Jung-Hwan Lee, Ahmed El-Fiqi, Nandin Mandakhbayar, Hae-Hyoung Lee, Hae-Won Kim
Regeneration of infected tissues is a globally challenging issue in medicine and dentistry. Common clinical therapies involving a complete removal of infected areas together with a treatment of antimicrobial drugs are often suboptimal. Biomaterials with anti-bacterial and pro-regenerative potential can offer a solution to this. Here we design a novel nanocarrier based on a mesoporous silicate-calcium glass by doping with Ag ions and simultaneously loading antimicrobial drugs onto mesopores. The nanocarriers could controllably release multiple ions (silver, calcium, and silicate) and drugs (tetracycline or chlorohexidine) to levels therapeutically relevant, and effectively internalize to human dental stem cells (∼90%) with excellent viability, ultimately stimulating odontogenic differentiation...
July 12, 2017: Biomaterials
https://www.readbyqxmd.com/read/28727190/tuning-the-effects-of-bacterial-membrane-permeability-through-photo-isomerization-of-antimicrobial-cationic-amphiphiles
#2
Micha Fridman, Joana Salta, Raphael I Benhamou, Ido M Herzog
Several last resort classes of antimicrobial drugs act by permeabilizing cell membranes. Here we demonstrate that insertion of a photo-isomerizable lipid into antimicrobial cationic amphiphiles can modify the intensity of their membrane-permeabilizing activity not only by their concentration but also through light-irradiation. We characterized the photo-isomerization effects of two types of cationic amphiphiles on their bacterial membrane permeabilizing activity and showed that while one photo-isomer inhibited cell growth and division, the other photo-isomer led to a rapid and lethal bacterial membrane-disrupting effect...
July 20, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28726635/as-cath1-6-novel-cathelicidins-with-potent-antimicrobial-and-immunomodulatory-properties-from-alligator-sinensis-play-pivotal-roles-in-host-anti-microbial-immune-responses
#3
Yan Chen, Shasha Cai, Xue Qiao, Mali Wu, Zhilai Guo, Renping Wang, Yi-Qun Kuang, Haining Yu, Yipeng Wang
Crocodilians are regarded as possessing a powerful immune system. However, the composition and action of crocodilian immune system has remained unclear until now. Cathelicidins, the principal family of host defense peptides, play pivotal roles in vertebrate immune defense against microbial invasions. However, cathelicidins from crocodilians have not been extensively studied to date. In the present study, six novel cathelicidins (As-CATH1~6) were identified and characterized from the endangered Chinese Alligator ( Alligator sinensis )...
July 18, 2017: Biochemical Journal
https://www.readbyqxmd.com/read/28726410/structural-insights-into-the-yersinia-pestis-outer-membrane-protein-ail-in-lipid-bilayers
#4
Samit Kumar Dutta, Yong Yao, Francesca M Marassi
Yersinia pestis the causative agent of plague, is highly pathogenic and poses very high risk to public health. The outer membrane protein Ail (Adhesion invasion locus) is one of the most highly expressed proteins on the cell surface of Y. pestis, and a major target for the development of medical countermeasures. Ail is essential for microbial virulence and is critical for promoting the survival of Y. pestis in serum. Structures of Ail have been determined by X-ray diffraction and solution NMR spectroscopy, but the protein's activity is influenced by the detergents in these samples, underscoring the importance of the surrounding environment for structure-activity studies...
July 20, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28725639/anaplasma-phagocytophilum-msp4-and-hsp70-proteins-are-involved-in-interactions-with-host-cells-during-pathogen-infection
#5
Marinela Contreras, Pilar Alberdi, Lourdes Mateos-Hernández, Isabel G Fernández de Mera, Ana L García-Pérez, Marie Vancová, Margarita Villar, Nieves Ayllón, Alejandro Cabezas-Cruz, James J Valdés, Snorre Stuen, Christian Gortazar, José de la Fuente
Anaplasma phagocytophilum transmembrane and surface proteins play a role during infection and multiplication in host neutrophils and tick vector cells. Recently, A. phagocytophilum Major surface protein 4 (MSP4) and Heat shock protein 70 (HSP70) were shown to be localized on the bacterial membrane, with a possible role during pathogen infection in ticks. In this study, we hypothesized that A. phagocytophilum MSP4 and HSP70 have similar functions in tick-pathogen and host-pathogen interactions. To address this hypothesis, herein we characterized the role of these bacterial proteins in interaction and infection of vertebrate host cells...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28723556/peroxisome-mediated-metabolism-is-required-for-immune-response-to-microbial-infection
#6
Francesca Di Cara, Avinash Sheshachalam, Nancy E Braverman, Richard A Rachubinski, Andrew J Simmonds
The innate immune response is critical for animal homeostasis and is conserved from invertebrates to vertebrates. This response depends on specialized cells that recognize, internalize, and destroy microbial invaders through phagocytosis. This is coupled to autonomous or non-autonomous cellular signaling via reactive oxygen species (ROS) and cytokine production. Lipids are known signaling factors in this process, as the acute phase response of macrophages is accompanied by systemic lipid changes that help resolve inflammation...
July 18, 2017: Immunity
https://www.readbyqxmd.com/read/28721849/effective-protection-of-mice-against-shigella-flexneri-with-a-new-self-adjuvant-multicomponent-vaccine
#7
Yadira Pastor, Ana Camacho, Ana Gloria Gil, Rocío Ramos, Adela López de Ceráin, Iván Peñuelas, Juan M Irache, Carlos Gamazo
PURPOSE: The aim of this study was to develop an immunogenic protective product against Shigella flexneri by employing a simple and safe heat treatment-based strategy. METHODOLOGY: The physicochemical characteristics of naturally produced (OMV) and heat-induced (HT) outer-membrane vesicles from S. flexneri were examined, including a comparison of the protein content of the products. Toxicological and biodistribution studies, and a preliminary experiment to examine the protective effectiveness of HT in a murine model of S...
July 18, 2017: Journal of Medical Microbiology
https://www.readbyqxmd.com/read/28721617/effect-of-membrane-property-and-feed-water-organic-matter-quality-on-long-term-performance-of-the-gravity-driven-membrane-filtration-process
#8
Dongwhi Lee, Yuri Lee, Shin Sik Choi, Sang-Ho Lee, Kyoung-Woong Kim, Yunho Lee
This study investigated the influence of membrane property and feed water organic matter quality on the permeate flux and water quality during gravity-driven membrane (GDM) filtration. GDM filtration was continuously carried out over 500 days at hydrostatic pressure of 65 mbar in dead-end mode without any back-flushing or membrane cleaning. Three ultrafiltration (UF) membranes (PES-100 kDa, PVDF-120 kDa, and PVDF-100 kDa) and one microfiltration (MF) membrane (PTFE-0.3 μm) were tested for treating lake water with varied organic matter qualities due to algal growth...
July 18, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28720964/antimicrobial-effect-of-black-pepper-petroleum-ether-extract-for-the-morphology-of-listeria-monocytogenes-and-salmonella-typhimurium
#9
Hui Tang, Wenxue Chen, Zu-Man Dou, Ronghao Chen, Yueying Hu, Weijun Chen, Haiming Chen
This study aimed to evaluate the effects of black pepper petroleum extract (BPPE) on pathogenic bacteria. The extraction from black pepper showed intense antimicrobial activity against the Gram-positive Listeria monocytogenes ATCC 19115 and the Gram-negative bacteria Salmonella typhimurium ATCC 14028. The minimum inhibitory concentrations of BPPE against L. monocytogenes and S. typhimurium were 0.625 and 1.25 mg/ml, respectively. Detection of Alkaline phosphatase outside the cell revealed that BPPE treatment destroyed the cell wall integrity...
June 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28720734/lack-of-acrb-efflux-function-confers-loss-of-virulence-on-salmonella-enterica-serovar-typhimurium
#10
Xuan Wang-Kan, Jessica M A Blair, Barbara Chirullo, Jonathan Betts, Roberto M La Ragione, Alasdair Ivens, Vito Ricci, Timothy J Opperman, Laura J V Piddock
AcrAB-TolC is the paradigm resistance-nodulation-division (RND) multidrug resistance efflux system in Gram-negative bacteria, with AcrB being the pump protein in this complex. We constructed a nonfunctional AcrB mutant by replacing D408, a highly conserved residue essential for proton translocation. Western blotting confirmed that the AcrB D408A mutant had the same native level of expression of AcrB as the parental strain. The mutant had no growth deficiencies in rich or minimal medium. However, compared with wild-type SL1344, the mutant had increased accumulation of Hoechst 33342 dye and decreased efflux of ethidium bromide and was multidrug hypersusceptible...
July 18, 2017: MBio
https://www.readbyqxmd.com/read/28720376/the-increase-in-positively-charged-residues-in-cecropin-d-like-galleria-mellonella-favors-its-interaction-with-membrane-models-that-imitate-bacterial-membranes
#11
José Oñate-Garzón, Alessio Ausili, Marcela Manrique-Moreno, Alejandro Torrecillas, Francisco J Aranda, Edwin Patiño, Juan C Gomez-Fernández
A comparative study of three synthetic peptides, namely neutral Cecropin D-like G. mellonella (WT) and two cationic peptides derived from its sequence, ΔM1 (+5) and ΔM2 (+9) is reported in this work. The influence of charge on the interactions between peptides and membranes and its effect on phase were studied by calorimetric assays. Differential scanning calorimetry (DSC) showed that ΔM2 peptide showed the strongest effect when the membrane contained phosphatidylcholine (PC) and phosphatidylglycerol (PG), increasing membrane fluidization...
July 15, 2017: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28718982/design-and-solution-phase-synthesis-of-membrane-targeting-lipopeptides-with-selective-antibacterial-activity
#12
Mohini Mohan Konai, Utsarga Adhikary, Jayanta Haldar
Designing selective antibacterial molecules remains an unmet goal in the field of membrane targeting agents. To this aim, herein we report the rational design and synthesis of a new class of lipopeptides which possess highly selective bacterial killing over mammalian cells. The selective interaction with bacterial over mammalian membranes was established through various spectroscopic as well as microscopic experiments including biophysical studies with the model membranes. A detailed antibacterial structure-activity relationship was delineated after preparing a series of molecules consisting of the peptide moieties with varied sequence of amino acids such as D-phenylalanine, D-leucine and D-lysine...
July 18, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28718822/a-bacterial-toxin-with-analgesic-properties-hyperpolarization-of-drg-neurons-by-mycolactone
#13
Ok-Ryul Song, Han-Byul Kim, Samuel Jouny, Isabelle Ricard, Alexandre Vandeputte, Nathalie Deboosere, Estelle Marion, Christophe J Queval, Pierre Lesport, Emmanuel Bourinet, Daniel Henrion, Seog Bae Oh, Guillaume Lebon, Guillaume Sandoz, Edouard Yeramian, Laurent Marsollier, Priscille Brodin
Mycolactone, a polyketide molecule produced by Mycobacterium ulcerans, is the etiological agent of Buruli ulcer. This lipid toxin is endowed with pleiotropic effects, presents cytotoxic effects at high doses, and notably plays a pivotal role in host response upon colonization by the bacillus. Most remarkably, mycolactone displays intriguing analgesic capabilities: the toxin suppresses or alleviates the pain of the skin lesions it inflicts. We demonstrated that the analgesic capability of mycolactone was not attributable to nerve damage, but instead resulted from the triggering of a cellular pathway targeting AT₂ receptors (angiotensin II type 2 receptors; AT₂R), and leading to potassium-dependent hyperpolarization...
July 18, 2017: Toxins
https://www.readbyqxmd.com/read/28717421/isolation-of-membrane-vesicles-from-prokaryotes-a-technical-and-biological-comparison-reveals-heterogeneity
#14
Priscila Dauros Singorenko, Vanessa Chang, Alana Whitcombe, Denis Simonov, Jiwon Hong, Anthony Phillips, Simon Swift, Cherie Blenkiron
Prokaryotes release membrane vesicles (MVs) with direct roles in disease pathogenesis. MVs are heterogeneous when isolated from bacterial cultures so Density Gradient Centrifugation (DGC) is valuable for separation of MV subgroups from contaminating material. Here we report the technical variability and natural biological heterogeneity seen between DGC preparations of MVs for Mycobacterium smegmatis and Escherichia coli and compare these DGC data with size exclusion chromatography (SEC) columns. Crude preparations of MVs, isolated from cultures by ultrafiltration and ultracentrifugation were separated by DGC with fractions manually collected as guided by visible bands...
2017: Journal of Extracellular Vesicles
https://www.readbyqxmd.com/read/28717145/acetylsalicylic-acid-differentially-limits-the-activation-and-expression-of-cell-death-markers-in-human-platelets-exposed-to-staphylococcus-aureus-strains
#15
Adrien Chabert, Pauline Damien, Paul O Verhoeven, Florence Grattard, Philippe Berthelot, Fabrice Zeni, Laurence Panicot-Dubois, Stéphane Robert, Françoise Dignat-George, Marie-Ange Eyraud, Bruno Pozzetto, Bernard Payrastre, Fabrice Cognasse, Olivier Garraud, Hind Hamzeh-Cognasse
Beyond their hemostatic functions, platelets alter their inflammatory response according to the bacterial stimulus. Staphylococcus aureus is associated with exacerbated inflammation and thrombocytopenia, which is associated with poor prognosis during sepsis. Acetylsalicylic acid and statins prevent platelet aggregation and decrease the mortality rate during sepsis. Therefore, we assessed whether these two molecules could reduce in vitro platelet activation and the inflammatory response to S. aureus. Platelets were exposed to clinical strains of S...
July 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28717042/modeling-the-kinetics-of-the-permeation-of-antibacterial-agents-into-growing-bacteria-and-its-interplay-with-efflux
#16
Wright W Nichols
A mathematical model of the passive permeation of a novel solute into bacteria is developed that explicitly accounts for intracellular dilution through growth. A bacterial cell envelope permeability coefficient of >10(-8) cm(2)s(-1) approx., is predicted to ensure passive permeation into rapidly replicating bacterial cells. The relative importance of the permeability coefficients of the cytoplasmic and outer membranes of Gram-negative bacteria in determining the overall envelope permeability coefficient is analyzed quantitatively...
July 17, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28716627/membrane-proteins-structures-a-review-on-computational-modeling-tools
#17
REVIEW
Jose G Almeida, Antonio J Preto, Panagiotis I Koukos, Alexandre M J J Bonvin, Irina S Moreira
BACKGROUND: Membrane proteins (MPs) play diverse and important functions in living organisms. They constitute 20% to 30% of the known bacterial, archaean and eukaryotic organisms' genomes. In humans, their importance is emphasized as they represent 50% of all known drug targets. Nevertheless, experimental determination of their three-dimensional (3D) structure has proven to be both time consuming and rather expensive, which has led to the development of computational algorithms to complement the available experimental methods and provide valuable insights...
July 14, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28715739/antimicrobial-and-antibiofilm-efficacy-of-self-cleaning-surfaces-functionalized-by-tio2-photocatalytic-nanoparticles-against-staphylococcus-aureus-and-pseudomonas-putida
#18
Blanca Jalvo, Marisol Faraldos, Ana Bahamonde, Roberto Rosal
A photocatalytic sol of TiO2 nanoparticles has been used for creating self-cleaning antimicrobial flat and porous glass surfaces. The substrates were irradiated to study their photocatalytic properties and behavior in the presence of biofilm-forming bacteria. Smooth glass surfaces and glass microfiber filters were covered with 1.98×10(-3)±1.5×10(-4)gcm(-2) and 8.55×10(-3)±3.0×10(-4)gcm(-2) densities, respectively. Self-cleaning properties were analyzed using the methylene blue 365nm UV-A photodegradation test...
July 5, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28714890/cardamom-cumin-and-dill-weed-essential-oils-chemical-compositions-antimicrobial-activities-and-mechanisms-of-action-against-campylobacter-spp
#19
Aysegul Mutlu-Ingok, Funda Karbancioglu-Guler
Natural antimicrobials as well as essential oils (EOs) have gained interest to inhibit pathogenic microorganisms and to control food borne diseases. Campylobacter spp. are one of the most common causative agents of gastroenteritis. In this study, cardamom, cumin, and dill weed EOs were evaluated for their antibacterial activities against Campylobacter jejuni and Campylobacter coli by using agar-well diffusion and broth microdilution methods, along with the mechanisms of antimicrobial action. Chemical compositions of EOs were also tested by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS)...
July 15, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28714554/type-ix-secretion-the-generation-of-bacterial-cell-surface-coatings-involved-in-virulence-gliding-motility-and-the-degradation-of-complex-biopolymers
#20
Paul D Veith, Michelle D Glew, Dhana G Gorasia, Eric C Reynolds
The Type IX Secretion System (T9SS) is present in over 1000 sequenced species/strains of the Fibrobacteres-Chlorobi-Bacteroidetes superphylum. Proteins secreted by the T9SS have an N-terminal signal peptide for translocation across the inner membrane via the SEC translocon and a C-terminal signal for secretion across the outer membrane via the T9SS. Nineteen protein components of the T9SS have been identified including three, SigP, PorX and PorY that are involved in regulation. The inner membrane proteins PorL and PorM and the outer membrane proteins PorK and PorN interact and a complex comprising PorK and PorN forms a large ring structure of 50 nm in diameter...
July 17, 2017: Molecular Microbiology
keyword
keyword
51792
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"