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https://www.readbyqxmd.com/read/28333237/new-paenibacillus-strain-produces-a-family-of-linear-and-cyclic-antimicrobial-lipopeptides-cyclization-is-not-essential-for-their-antimicrobial-activity
#1
En Huang, Xu Yang, Liwen Zhang, Sun Hee Moon, Ahmed E Yousef
A new bacterial isolate, Paenibacillus sp. OSY-N, showed potent antimicrobial activity against Gram-negative and Gram-positive bacteria. Antimicrobials produced by this strain were purified by reverse-phase high performance liquid chromatography (HPLC). Structural analysis, using mass spectrometry (MS), of a single active HPLC fraction revealed two known cyclic lipopeptides, BMY-28160 and permetin A, a new cyclic lipopeptide, and the linear counterparts of these cyclic compounds. The latter were designated as paenipeptin A, B and C, respectively...
February 25, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28330259/identification-of-endophytic-bacillus-mojavensis-with-highly-specialized-broad-spectrum-antibacterial-activity
#2
B Jasim, S Sreelakshmi, Jyothis Mathew, E K Radhakrishnan
Biosynthetic adaptation of endophytic bacteria to chemically support host plant is very remarkable. Hence these organisms from medicinal plants are considered as highly valuable sources for natural products with diverse bioactivity. Their metabolite diversity and biosynthetic versatility have been increasingly explored for drug discovery. In this study, an endophytic Bacillus mojavensis with broad spectrum antibacterial properties has been analyzed for the chemical basis of its activity. By LC-MS/MS the organism was identified to have the biosynthetic ability to produce lipopeptides surfactin and fengycin...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330114/evaluation-of-orange-peel-for-biosurfactant-production-by-bacillus-licheniformis-and-their-ability-to-degrade-naphthalene-and-crude-oil
#3
Arthala Praveen Kumar, Avilala Janardhan, Buddolla Viswanath, Kallubai Monika, Jin-Young Jung, Golla Narasimha
A Gram-positive bacterium was isolated from mangrove soil and was identified as Bacillus licheniformis (KC710973). The potential of a mangrove microorganism to utilize different natural waste carbon substrates for biosurfactant production and biodegradation of hydrocarbons was evaluated. Among several substrates used in the present study, orange peel was found to be best substrate of biosurfactant yield with 1.796 g/L and emulsification activity of 75.17 % against diesel. Fourier transform infrared spectroscopy analysis of biosurfactant compound revealed that the isolated biosurfactant is in lipopeptide nature...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28329302/sensitization-of-gram-negative-bacilli-to-host-antibacterial-proteins
#4
Joanna Jammal, Fadia Zaknoon, Galoz Kaneti, Ayelet S Hershkovits, Amram Mor
Towards addressing the need for novel alternatives to antibiotics, we attempted to sensitize Gram-negative bacilli (GNB) to innate antibacterial protagonists. We report a lipopeptide-like sequence (C10OOc12O) that inflicted outer-membrane damages at low micromolar range, whereas measurable bacterial growth inhibition in broth medium required >10-fold higher concentrations. In serum however, C10OOc12O induced antibacterial activity in a manner suppressible by anti-complements antibodies or heat treatment, and acted synergistically with exogenous lysozyme in broth and serum media...
March 4, 2017: Journal of Infectious Diseases
https://www.readbyqxmd.com/read/28323017/whole-genome-sequencing-of-bacillus-velezensis-ls69-a-strain-with-a-broad-inhibitory-spectrum-against-pathogenic-bacteria
#5
Guoqiang Liu, Yingying Kong, Yajing Fan, Ce Geng, Donghai Peng, Ming Sun
Bacillus velezensis LS69 was found to exhibit antagonistic activity against a diverse spectrum of pathogenic bacteria. It has one circular chromosome of 3,917,761bp with 3,643 open reading frames. Genome analysis identified ten gene clusters involved in nonribosomal synthesis of polyketides (macrolactin, bacillaene and difficidin), lipopeptides (surfactin, fengycin, bacilysin and iturin A) and bacteriocins (amylolysin and amylocyclicin). In addition, B. velezensis LS69 was found to contain a series of genes involved in enhancing plant growth and triggering plant immunity...
March 17, 2017: Journal of Biotechnology
https://www.readbyqxmd.com/read/28302403/surfactin-variants-for-intra-intestinal-delivery-of-insulin
#6
Li Zhang, Xiaoying Xing, Jia Ding, Xiuyun Zhao, Gaofu Qi
Surfactin is a Bacillus-produced natural lipopeptide, which can overcome the epithelial cell barriers for orally delivering insulin, but its ability to promote uptake of insulin by the intestine need to be further improved for a higher oral bioavailability. Here, we designed and synthesized several surfactin variants to improve its ability for oral delivery of insulin. Firstly, we replaced Glu with Gln in surfactin for decreasing its negative charges, but found this replacement weakened its ability to orally delivery insulin...
March 13, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28300674/structure-activity-studies-on-polymyxin-derivatives-carrying-three-positive-charges-only-reveal-a-new-class-of-compounds-with-strong-antibacterial-activity
#7
Martti Vaara, Timo Vaara, Jonathan M Tyrrell
Recent years have brought in an increased interest to develop improved polymyxins. The currently used polymyxins, i.e. polymyxin B and colistin (polymyxin E) are pentacationic lipopeptides that possess a cyclic heptapeptide part with three positive charges, a linear "panhandle" part with two positive charges, and a fatty acyl tail. Unfortunately, their clinical use is shadowed by their notable nephrotoxicity. We have previously developed a polymyxin derivative NAB739 which lacks the positive charges in the linear part...
March 11, 2017: Peptides
https://www.readbyqxmd.com/read/28294609/biseokeaniamides-a-b-and-c-sterol-o-acyltransferase-inhibitors-from-an-okeania-sp-marine-cyanobacterium
#8
Arihiro Iwasaki, Takato Tadenuma, Shimpei Sumimoto, Taichi Ohshiro, Kaori Ozaki, Keisuke Kobayashi, Toshiaki Teruya, Hiroshi Tomoda, Kiyotake Suenaga
Biseokeaniamides A, B, and C (1-3), structurally novel sterol O-acyltransferase (SOAT) inhibitors, were isolated from an Okeania sp. marine cyanobacterium. Their structures were elucidated by spectroscopic analyses and degradation reactions. Biseokeaniamide B (2) exhibited moderate cytotoxicity against human HeLa cancer cells, and compounds 1-3 inhibited both SOAT1 and SOAT2, not only at an enzyme level but also at a cellular level. Biseokeaniamides (1-3) are the first linear lipopeptides that have been shown to exhibit SOAT-inhibitory activity...
March 15, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28288360/biosurfactant-assisted-recovery-of-the-c5-c11-hydrocarbon-fraction-from-oily-sludge-using-biosurfactant-producing-consortium-culture-of-bacteria
#9
Evans M Nkhalambayausi Chirwa, Chidinyane T Mampholo, Oluwademilade M Fayemiwo, Fisseha A Bezza
A biosurfactant producing culture of bacteria was isolated from an automobile engine oil dump site which was later used as an inoculum in batch and continuous flow oil recovery from oily sludge. Initially, an emulsion of oily sludge was prepared by mixing 5% m/v solids: 21% v/v bituminous sludge: 77% v/v water. The isolated cultures were added to vessels with stable emulsions to facilitate the separation of oil droplets from the sludge matrix. In batches with live cultures, up to 35% oil recovery was achieved after incubation for 10 days...
March 10, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28274989/nadph-oxidase-nox2-mediates-tlr2-6-dependent-release-of-gm-csf-from-endothelial-cells
#10
Jutta Schuett, Harald Schuett, Raghav Oberoi, Ann-Kathrin Koch, Silke Pretzer, Maren Luchtefeld, Bernhard Schieffer, Karsten Grote
NADPH oxidase-generated reactive oxygen species (ROS) from immune cells are well known to be important for pathogen killing in response to TLR ligands. Here, we investigated a new aspect of NADPH oxidase in the TLR2/6-induced release of the immunologically relevant GM-CSF by endothelial cells. Stimulation of human endothelial cells with TLR2/6 agonist, MALP-2 (macrophage-activating lipopeptide of 2 kDa), induced NADPH oxidase activation and ROS formation. Inhibition by ROS scavengers and NADPH oxidase inhibitors blocked MALP-2-induced GM-CSF release...
March 8, 2017: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/28252162/identification-of-lipopeptides-produced-by-bacillus-subtilis-czk1-isolated-from-the-aerial-roots-of-rubber-trees
#11
C P He, L Y Fan, W H Wu, Y Q Liang, R Li, W Tang, X L Zheng, Y N Xiao, Z X Liu, F C Zheng
We obtained a strain of Bacillus subtilis, which we named Czk1, from the aerial roots of rubber trees. This bacterial isolate exhibits strong antagonistic activity against Ganoderma pseudoferreum, Phellinus noxius, Helicobasidium compactum, Rigidoporus lignosus, Sphaerostilbe repens, and Colletotrichum gloeosporioides. Our earlier research has shown that the antagonistic activity of a fermentation supernatant Czk1 isolate produces a complex mixture of lipopeptides. In this study, we used methanol to extract crude lipopeptides, purified them using a Sephadex G-25 column, cloned the lipopeptide genes, and analyzed purified fractions by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) to identify the lipopeptides from B...
February 23, 2017: Genetics and Molecular Research: GMR
https://www.readbyqxmd.com/read/28243887/dendritic-cells-targeting-and-ph-responsive-multi-layered-nanocomplexes-for-smart-delivery-of-dna-vaccines
#12
Menglu Xu, Yulin Chen, Parikshit Banerjee, Li Zong, Lei Jiang
Specific and effective delivery of DNA vaccines into dendritic cells (DCs) to express antigens is a precondition for induction of immune responses. Construction of a new DNA vaccine delivery system with the ability of programmed gene transfection may achieve this objective. In this study, we successfully integrated dendritic lipopeptide, charge-reversible polymer, and APC-targeted material into DNA vaccine delivery system through layer-by-layer (LBL) assembly. By the means of adjusting the weight ratios and concentration ratios of components, stable complexes were formulated with a particle size of 256...
February 27, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28236981/phase-i-ii-study-of-tecemotide-as-immunotherapy-in-japanese-patients-with-unresectable-stage-iii-non-small-cell-lung-cancer
#13
Nobuyuki Katakami, Toyoaki Hida, Hiroshi Nokihara, Fumio Imamura, Hiroshi Sakai, Shinji Atagi, Makoto Nishio, Tatsuhiko Kashii, Miyako Satouchi, Christoph Helwig, Morihiro Watanabe, Tomohide Tamura
OBJECTIVES: Unresectable stage III NSCLC (non-small cell lung cancer) confers a poor prognosis and interest is growing in the use of immunotherapy to improve outcomes for patients with this disease. We investigated the safety and efficacy of maintenance tecemotide, a mucin 1 (MUC1)-specific agent that induces T-cell responses to MUC1, versus placebo in Japanese patients with stage III unresectable NSCLC and no disease progression after primary chemoradiotherapy. MATERIALS AND METHODS: Patients aged ≥20 years with unresectable stage III NSCLC, stable disease or clinical response after primary chemoradiotherapy and performance status ≤1, were recruited across 25 centers in Japan...
March 2017: Lung Cancer: Journal of the International Association for the Study of Lung Cancer
https://www.readbyqxmd.com/read/28217113/antimicrobial-and-insecticidal-cyclic-lipopeptides-and-hydrogen-cyanide-produced-by-plant-beneficial-pseudomonas-strains-cha0-cmr12a-and-pcl1391-contribute-to-insect-killing
#14
Pascale Flury, Pilar Vesga, Maria Péchy-Tarr, Nora Aellen, Francesca Dennert, Nicolas Hofer, Karent P Kupferschmied, Peter Kupferschmied, Zane Metla, Zongwang Ma, Sandra Siegfried, Sandra de Weert, Guido Bloemberg, Monica Höfte, Christoph J Keel, Monika Maurhofer
Particular groups of plant-beneficial fluorescent pseudomonads are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. The mechanisms by which the bacteria manage to infest this alternative host, to overcome its immune system, and to ultimately kill the insect are still largely unknown. However, the investigation of the few virulence factors discovered so far, points to a highly multifactorial nature of insecticidal activity. Antimicrobial compounds produced by fluorescent pseudomonads are effective weapons against a vast diversity of organisms such as fungi, oomycetes, nematodes, and protozoa...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28214849/lipopeptide-induced-suicidal-erythrocyte-death-correlates-with-the-degree-of-acylation
#15
Abdulla Al Mamun Bhuyan, Minh-Thu Nguyen, Rosi Bissinger, Friedrich Götz, Florian Lang
BACKGROUND/AIMS: Consequences of bacterial infection include anemia, which could result from stimulation of suicidal erythrocyte death or eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Bacterial components known to stimulate eryptosis include lipopeptides. Signaling mediating the triggering of eryptosis include increased cytosolic Ca2+ activity ([Ca2+]<Sub>i</Sub>), oxidative stress and cellular accumulation of ceramide...
January 24, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/28211996/alternating-current-electrophoretic-deposition-for-the-immobilization-of-antimicrobial-agents-on-titanium-implant-surfaces
#16
Annabel Braem, Katrijn De Brucker, Nicolas Delattin, Manuela S Killian, Maarten B J Roeffaers, Tomohiko Yoshioka, Satoshi Hayakawa, Patrik Schmuki, Bruno P A Cammue, Sannakaisa Virtanen, Karin Thevissen, Bram Neirinck
One prominent cause of implant failure is infection; therefore, research is focusing on developing surface coatings that render the surface resistant to colonization by micro-organisms. Permanently attached coatings of antimicrobial molecules are of particular interest because of the reduced cytoxicity and lower risk of developing resistance compared to controlled release coatings. In this study, we focus on the chemical grafting of bioactive molecules on titanium. To concentrate the molecules at the metallic implant surface, we propose electrophoretic deposition (EPD) applying alternating current (AC) signals with an asymmetrical wave shape...
March 6, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28209400/multidrug-resistant-enterococcal-infections-new-compounds-novel-antimicrobial-therapies
#17
REVIEW
Roel M van Harten, Rob J L Willems, Nathaniel I Martin, Antoni P A Hendrickx
Over the past two decades infections due to antibiotic-resistant bacteria have escalated world-wide, affecting patient morbidity, mortality, and health care costs. Among these bacteria, Enterococcus faecium and Enterococcus faecalis represent opportunistic nosocomial pathogens that cause difficult-to-treat infections because of intrinsic and acquired resistance to a plethora of antibiotics. In recent years, a number of novel antimicrobial compound classes have been discovered and developed that target Gram-positive bacteria, including E...
February 13, 2017: Trends in Microbiology
https://www.readbyqxmd.com/read/28207237/simultaneous-determination-of-absolute-configuration-and-quantity-of-lipopeptides-using-chiral-liquid-chromatography-mass-spectrometry-and-diastereomeric-internal-standards
#18
Reza Nemati, Christopher Dietz, Emily Anstadt, Robert Clark, Michael Smith, Frank Nichols, Xudong Yao
Lipopeptides promote innate immune response and are related to disease pathology. To investigate the newly emerging roles of lipopeptides, accurate measurements of stereoisomers with multiple chiral centers are essential yet challenging. This work uses (3R)- and (3S)-(15-methyl-3-((13-methyltetradecanoyl)oxy)hexadecanoyl)glycyl-l-serine, abbreviated as l-serine-(R+S)-Lipid 654, to develop a method that combines chiral liquid chromatography, a diastereomeric mixture of isotopically labeled internal standards, and multiple reaction monitoring mass spectrometry...
March 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28203232/cationic-net-charge-and-counter-ion-type-as-antimicrobial-activity-determinant-factors-of-short-lipopeptides
#19
Katarzyna E Greber, Malgorzata Dawgul, Wojciech Kamysz, Wieslaw Sawicki
To get a better insight into the antimicrobial potency of short cationic lipopeptides, 35 new entities were synthesized using solid phase peptide strategy. All newly obtained lipopeptides were designed to be positively charged from +1 to +4. This was achieved by introducing basic amino acid - lysine - into the lipopeptide structure and had a hydrophobic fatty acid chain attached. Lipopeptides were subjected to microbiological tests using reference strains of Gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, Gram-positive bacteria: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Enterococcus faecalis, and fungi: Candida albicans, Candida tropicalis, Aspergillus brasiliensis...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28201868/enzyme-responsive-liposomes-for-the-delivery-of-anticancer-drugs
#20
Farnaz Fouladi, Kristine J Steffen, Sanku Mallik
Liposomes are nanocarriers that deliver the payloads at the target site, leading to therapeutic drug concentrations at the diseased site and reduced toxic effects in healthy tissues. Several approaches have been used to enhance the ability of the nanocarrier to target the specific tissues, including ligand-targeted liposomes and stimuli-responsive liposomes. Ligand-targeted liposomes exhibit higher uptake by the target tissue due to the targeting ligand attached to the surface, while, the stimuli-responsive liposomes do not release their cargo unless they expose to an endogenous or exogenous stimulant at the target site...
February 16, 2017: Bioconjugate Chemistry
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