keyword
MENU ▼
Read by QxMD icon Read
search

bacteria membrane

keyword
https://www.readbyqxmd.com/read/28731688/the-%C3%AF-configuration-of-the-www-motif-of-a-short-trp-rich-peptide-is-critical-for-targeting-bacterial-membranes-disrupting-preformed-biofilms-and-killing-methicillin-resistant-staphylococcus-aureus
#1
D Zarena, Biswajit Mishra, Tamara Lushnikova, Fangyu Wang, Guangshun Wang
Tryptophan-rich peptides, being short and suitable for large-scale chemical synthesis, are attractive candidates for developing a new generation of antimicrobials to combat antibiotic-resistant bacteria (superbugs). Although there are numerous pictures for membrane-bound structure of a single tryptophan (W), how multiple Trp amino acids assemble themselves and interact with bacterial membranes are poorly understood. This communication presents the three-dimensional structure for an eight-residue Trp-rich peptide (WWWLRKIW-NH2 with 50% W) determined by the improved 2D NMR method, which includes the measurements of 13C and 15N chemical shifts at natural abundance...
July 21, 2017: Biochemistry
https://www.readbyqxmd.com/read/28730976/salmonella-intracellular-lifestyles-and-their-impact-on-host-to-host-transmission
#2
M Graciela Pucciarelli, Francisco García-Del Portillo
More than a century ago, infections by Salmonella were already associated with foodborne enteric diseases with high morbidity in humans and cattle. Intestinal inflammation and diarrhea are hallmarks of infections caused by nontyphoidal Salmonella serovars, and these pathologies facilitate pathogen transmission to the environment. In those early times, physicians and microbiologists also realized that typhoid and paratyphoid fever caused by some Salmonella serovars could be transmitted by "carriers," individuals outwardly healthy or at most suffering from some minor chronic complaint...
July 2017: Microbiology Spectrum
https://www.readbyqxmd.com/read/28730802/sensing-single-molecule-penetration-into-nanopores-pushing-the-time-resolution-to-the-diffusion-limit
#3
Igor Bodrenko, Jiajun Wang, Samuele Salis, Mathias Winterhalter, Matteo Ceccarelli
To quantify small molecule penetration into and eventually permeation through nanopores, we applied an improved excess-noise analysis of the ion current fluctuation caused by entering molecules. The kinetic parameters of substrate entry and leave are derived from a two-state Markov model, analyzing the substrate concentration depen- dence of the average ion current and its variance. Including filter corrections allows one to detect the transition rates beyond the cutoff frequency, fc, of the instrumental ion-current filter...
July 21, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28730370/the-n-terminal-and-central-domain-of-colicin-a-enables-phage-lysin-to-lyse-escherichia-coli-extracellularly
#4
Guangmou Yan, Jianfang Liu, Qiang Ma, Rining Zhu, Zhimin Guo, Chencheng Gao, Shuang Wang, Ling Yu, Jingmin Gu, Dongliang Hu, Wenyu Han, Rui Du, Junling Yang, Liancheng Lei
Multidrug-resistant Escherichia coli has seriously threatened antibiotic resources and international public health. Bacteriophage lysin preparations have been widely considered as valid agents for solving multidrug resistances. Many lysins have been derived to treat diseases caused by Gram-positive bacteria, but only a few lysin preparations have been found that successively treat diseases caused by Gram-negative bacteria. The outer membrane of Gram-negative bacteria effectively blocks the interactions between peptidoglycan in the periplasmic space and bacteriophage lysins, which therefore hampers the antimicrobial effects of bacteriophage lysins...
July 20, 2017: Antonie Van Leeuwenhoek
https://www.readbyqxmd.com/read/28728970/the-staphylococcus-aureus-fasii-bypass-escape-route-from-fasii-inhibitors
#5
REVIEW
Claire Morvan, David Halpern, Gérald Kénanian, Amit Pathania, Jamila Mondoloni-Anba, Gilles Lamberet, Alexandra Gruss, Karine Gloux
Antimicrobials targeting the fatty acid synthesis (FASII) pathway are being developed as alternative treatments for bacterial infections. Emergence of resistance to FASII inhibitors was mainly considered as a consequence of mutations in the FASII target genes. However, an alternative and efficient anti-FASII resistance strategy, called here FASII bypass, was uncovered. Bacteria that bypass FASII make use of exogenous fatty acids to build their membranes, and thus dispense with the need for FASII. This strategy is used by numerous Gram-positive low GC% bacteria, including streptococci, enterococci, and staphylococci...
July 17, 2017: Biochimie
https://www.readbyqxmd.com/read/28728309/escherichia-coli-outer-membrane-protein-f-ompf-an-immunogenic-protein-induces-cross-reactive-antibodies-against-escherichia-coli-and-shigella
#6
Xiao Wang, Da Teng, Qingfeng Guan, Ruoyu Mao, Ya Hao, Xiumin Wang, Junhu Yao, Jianhua Wang
Diarrhea caused by pathogenic Escherichia coli (E. coli) is one of the most serious infectious diseases in humans and animals. Due to antibiotics resistance and the lack of efficient vaccine, more attention should be paid to find potential versatile vaccine candidates to prevent diseases. In this study, the sequence homology analysis indicated that OmpF from E. coli CVCC 1515 shares a high identity (90-100%) with about half of the E. coli (46.7%) and Shigella (52.8%) strains. Then the recombinant OmpF was supposed to be developed as a versatile vaccine to prevent E...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28727999/drug-ion-co-delivery-multi-functional-nanocarrier-to-regenerate-infected-tissue-defect
#7
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/28726924/peculiarities-of-thermal-denaturation-of-ompf-porin-from-yersinia-ruckeri
#8
Olga D Novikova, Dmitry K Chistyulin, Valentina A Khomenko, Evgeny V Sidorin, Natalya Yu Kim, Nina M Sanina, Olga Yu Portnyagina, Tamara F Solov'eva, Vladimir N Uversky, Valery L Shnyrov
Irreversible denaturation of membrane proteins in detergent solutions is similar to unfolding of water-soluble multidomain proteins and represents a complex, multistage process. Pore-forming proteins of Gram-negative bacteria are heat-modifiable proteins, i.e., proteins altering their molecular forms (trimers or monomers), and accordingly, their electrophoretic mobilities depending upon denaturation conditions. There are still some contradictory data on the peculiarities of the conformational changes in the porin structure with temperature...
July 20, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28724349/16s-rrna-gene-based-association-study-identified-microbial-taxa-associated-with-pork-intramuscular-fat-content-in-feces-and-cecum-lumen
#9
Shaoming Fang, Xingwei Xiong, Ying Su, Lusheng Huang, Congying Chen
BACKGROUND: Intramuscular fat (IMF) that deposits among muscle fibers or within muscle cells is an important meat quality trait in pigs. Previous studies observed the effects of dietary nutrients and additives on improving the pork IMF. Gut microbiome plays an important role in host metabolism and energy harvest. Whether gut microbiota exerts effect on IMF remains unknown. RESULTS: In this study, we investigated the microbial community structure of 500 samples from porcine cecum and feces using high-throughput 16S rRNA gene sequencing...
July 19, 2017: BMC Microbiology
https://www.readbyqxmd.com/read/28724342/periodontal-disease-and-intra-amniotic-complications-in-women-with-preterm-prelabor-rupture-of-membranes
#10
Vladimira Radochova, Ivana Kacerovska Musilova, Martin Stepan, Peter Vescicik, Radovan Slezak, Bo Jacobsson, Marian Kacerovsky
OBJECTIVE: Periodontal disease is frequently suggested as a possible causal factor for preterm delivery. The link between periodontal disease and preterm delivery is a possible translocation of periopathogenic bacteria to the placenta and amniotic fluid as well as a systemic response to this chronic inflammatory disease. However, there is a lack of information on whether there is an association between clinical periodontal status in women with preterm prelabor rupture of membranes (PPROM) and the presence of microbial invasion of the amniotic cavity (MIAC) and intra-amniotic inflammation (IAI)...
July 20, 2017: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/28723891/the-lysosomal-potassium-channel-tmem175-adopts-a-novel-tetrameric-architecture
#11
Changkeun Lee, Jiangtao Guo, Weizhong Zeng, Sunghoon Kim, Ji She, Chunlei Cang, Dejian Ren, Youxing Jiang
TMEM175 is a lysosomal K(+) channel that is important for maintaining the membrane potential and pH stability in lysosomes. It contains two homologous copies of a six-transmembrane-helix (6-TM) domain, which has no sequence homology to the canonical tetrameric K(+) channels and lacks the TVGYG selectivity filter motif found in these channels. The prokaryotic TMEM175 channel, which is present in a subset of bacteria and archaea, contains only a single 6-TM domain and functions as a tetramer. Here, we present the crystal structure of a prokaryotic TMEM175 channel from Chamaesiphon minutus, CmTMEM175, the architecture of which represents a completely different fold from that of canonical K(+) channels...
July 19, 2017: Nature
https://www.readbyqxmd.com/read/28723556/peroxisome-mediated-metabolism-is-required-for-immune-response-to-microbial-infection
#12
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/28721045/synthesis-construction-and-evaluation-of-self-assembled-nano-bacitracin-a-as-an-efficient-antibacterial-agent-in-vitro-and-in-vivo
#13
Wei Hong, Xiang Gao, Peng Qiu, Jie Yang, Mingxi Qiao, Hong Shi, Dexian Zhang, Chunlian Tian, Shengli Niu, Mingchun Liu
Bacitracin A (BA) is an excellent polypeptide antibiotic that is active against gram-positive bacteria without triggering multidrug resistance. However, BA is inactive against gram-negative bacteria because of its inability to cross the outer membrane of these cells, and it has strong nephrotoxicity, thus limiting its clinical applications. Nanoantibiotics can effectively localize antibiotics to the periplasmic space of bacteria while decreasing the adverse effects of antibiotics. In this study, biodegradable hydrophobic copolymers of poly (d,l-lactide-co-glycolide) (PLGA) were attached to the N-termini of BA to design a novel class of self-assembled nano-bacitracin A (nano-BAs), and their potential as antibacterial agents was evaluated in vitro and in vivo...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28720964/antimicrobial-effect-of-black-pepper-petroleum-ether-extract-for-the-morphology-of-listeria-monocytogenes-and-salmonella-typhimurium
#14
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
#15
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/28720728/disguised-as-a-sulfate-reducer-growth-of-the-deltaproteobacterium-desulfurivibrio-alkaliphilus-by-sulfide-oxidation-with-nitrate
#16
Casper Thorup, Andreas Schramm, Alyssa J Findlay, Kai W Finster, Lars Schreiber
This study demonstrates that the deltaproteobacterium Desulfurivibrio alkaliphilus can grow chemolithotrophically by coupling sulfide oxidation to the dissimilatory reduction of nitrate and nitrite to ammonium. Key genes of known sulfide oxidation pathways are absent from the genome of D. alkaliphilus Instead, the genome contains all of the genes necessary for sulfate reduction, including a gene for a reductive-type dissimilatory bisulfite reductase (DSR). Despite this, growth by sulfate reduction was not observed...
July 18, 2017: MBio
https://www.readbyqxmd.com/read/28718982/design-and-solution-phase-synthesis-of-membrane-targeting-lipopeptides-with-selective-antibacterial-activity
#17
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/28717425/high-throughput-nanoparticle-tracking-analysis-for-monitoring-outer-membrane-vesicle-production
#18
Matthias J H Gerritzen, Dirk E Martens, René H Wijffels, Michiel Stork
Outer membrane vesicles (OMVs) are spherical membrane nanoparticles released by Gram-negative bacteria. OMVs can be quantified in complex matrices by nanoparticle tracking analysis (NTA). NTA can be performed in static mode or with continuous sample flow that results in analysis of more particles in a smaller time-frame. Flow measurements must be performed manually despite the availability of a sample changer on the NanoSight system. Here we present a method for automated measurements in flow mode. OMV quantification in flow mode results in lower variance in particle quantification (coefficient of variation (CV) of 6%, CV static measurements of 14%)...
2017: Journal of Extracellular Vesicles
https://www.readbyqxmd.com/read/28717421/isolation-of-membrane-vesicles-from-prokaryotes-a-technical-and-biological-comparison-reveals-heterogeneity
#19
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/28717042/modeling-the-kinetics-of-the-permeation-of-antibacterial-agents-into-growing-bacteria-and-its-interplay-with-efflux
#20
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
keyword
keyword
51790
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"