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bacterial lysate

Andrés Corral Lugo, Abdelali Daddaoua, Alvaro Ortega, Bertrand Morel, Ana Isabel Díez Peña, Manuel Espinosa-Urgel, Tino Krell
Quorum sensing systems are essential for bacterial communication. We report here the purification and characterization of the Pseudomonas aeruginosa LasR quorum sensing regulator purified from lysates of E. coli cultures grown in the absence of added acyl-homoserine lactones (AHL). We show by isothermal titration calorimetry that LasR recognizes different AHLs with an affinity of approximately 1 μM. The affinity of LasR for its cognate 3-Oxo-C12-AHL was similar to that of other AHLs, indicating that this regulator has not evolved to preferentially recognize its cognate AHL...
October 15, 2016: Protein Expression and Purification
Patricia Rubio Reyes, Natalie A Parlane, D Neil Wedlock, Bernd H A Rehm
Traditional approaches to vaccine development have failed to identify better vaccines to replace or supplement BCG for the control of tuberculosis (TB). Subunit vaccines offer a safer and more reproducible alternative for the prevention of diseases. In this study, the immunogenicity of bacterially derived polyester beads displaying three different Rv antigens of Mycobacterium tuberculosis was evaluated. Polyester beads displaying the antigens Rv1626, Rv2032, Rv1789, respectively, were produced in an endotoxin-free Escherichia coli strain...
October 13, 2016: International Journal of Medical Microbiology: IJMM
Dar-Chone Chow, Kacie Rice, Wanzhi Huang, Robert L Atmar, Timothy G Palzkill
The β-lactamase inhibitory protein (BLIP) binds and inhibits a wide range of class A β-lactamases including the TEM-1 β-lactamase (Ki= 0.5 nM), which is widely present in Gram-negative bacteria, and the KPC-2 β-lactamase (Ki= 1.2 nM), which hydrolyzes virtually all clinically useful β-lactam antibiotics. The extent to which the specificity of a protein that binds a broad range of targets can be modified to display narrow specificity was explored in this study by engineering BLIP to bind selectively to KPC-2 β-lactamase...
October 18, 2016: ACS Infectious Diseases
Paul Leonard, Stephen Hearty, Hui Ma, Richard O'Kennedy
The use of optical biosensors for studying macromolecular interactions is gaining increasing popularity. In one study, 1514 papers that involved the application of biosensor data were identified for the year 2009 alone (Rich and Myszka, J Mol Recognit 24:892-914, 2011), the sheer volume and variety of which present a daunting task for the burgeoning biosensor user to accumulate and decipher. This chapter is designed to provide the reader with the tools necessary to prepare, design, and efficiently execute a kinetic experiment on Biacore...
2017: Methods in Molecular Biology
Mijeong Park, Mark J Raftery, Paul S Thomas, Carolyn L Geczy, Katherine Bryant, Nicodemus Tedla
FcγRI cross-linking on monocytes may trigger clathrin-mediated endocytosis, likely through interaction of multiple intracellular molecules that are controlled by phosphorylation and dephosphorylation events. However, the identity of phospho-proteins and their regulation are unknown. We proposed the leukocyte immunoglobulin-like receptor B4 (LILRB4) that inhibits FcγRI-mediated cytokine production via Tyr dephosphorylation of multiple kinases, may also regulate endocytosis/phagocytosis through similar mechanisms...
October 11, 2016: Scientific Reports
Maxime Toussaint, Cyril Bontemps, Arnaud Besserer, Laurence Hotel, Philippe Gérardin, Pierre Leblond
Fungal biodegradation of wood is one of the main threats regarding its use as a material. So far, the detection of this decaying process is empirically assessed by loss of mass, when the fungal attack is advanced and woody structure already damaged. Being able to detect fungal attack on wood in earlier steps is thus of special interest for the wood economy. In this aim, we designed here a new diagnostic tool for wood degradation detection based on the bacterial whole-cell biosensor technology. It was designed in diverting the soil bacteria Streptomyces CebR sensor system devoted to cellobiose detection, a cellulolytic degradation by-product emitted by lignolytic fungi since the onset of wood decaying process...
October 8, 2016: Journal of Biotechnology
A Rodrigues, L P Gualdi, R G de Souza, M H M Vargas, N K Nuñez, A A da Cunha, M H Jones, L A Pinto, R T Stein, P M Pitrez
BACKGROUND: OM-85 is an immunostimulant bacterial lysate, which has been proven effective in reducing the number of lower airways infections. We investigated the efficacy of the bacterial lysate OM-85 in the primary prevention of a murine model of asthma. METHODS: In the first phase of our study the animals received doses of 0.5μg, 5μg and 50μg of OM-85 through gavage for five days (days -10 to -6 of the protocol), 10 days prior to starting the sensitisation with ovalbumin (OVA), in order to evaluate the results of dose-response protocols...
October 1, 2016: Allergologia et Immunopathologia
Fabian A Crespo, Christopher K Klaes, Andrew E Switala, Sharon N DeWitte
: It is possible that during long lasting chronic infections such as tuberculosis (TB) and leprosy individuals who generate a stronger immune response will produce a chronic shift in the systemic levels of inflammatory proteins. Consequently, the systemic immunological shift could affect inflammatory responses against other persistent pathogens such as Porphyromonas gingivalis associated with periodontal disease (PD). OBJECTIVE: To determine if in vitro exposure to Mycobacterium tuberculosis or M...
October 5, 2016: American Journal of Physical Anthropology
C Preston Neff, Matthew E Rhodes, Kathleen L Arnolds, Colm B Collins, Jody Donnelly, Nichole Nusbacher, Paul Jedlicka, Jennifer M Schneider, Martin D McCarter, Michael Shaffer, Sarkis K Mazmanian, Brent E Palmer, Catherine A Lozupone
Zwitterionic capsular polysaccharides (ZPSs) are bacterial products that modulate T cells, including inducing anti-inflammatory IL-10-secreting T regulatory cells (Tregs). However, only a few diverse bacteria are known to modulate the host immune system via ZPS. We present a genomic screen for bacteria encoding ZPS molecules. We identify diverse host-associated bacteria, including commensals and pathogens with known anti-inflammatory properties, with the capacity to produce ZPSs. Human mononuclear cells stimulated with lysates from putative ZPS-producing bacteria induce significantly greater IL-10 production and higher proportions of Tregs than lysates from non-ZPS-encoding relatives or a commensal strain of Bacteroides cellulosilyticus in which a putative ZPS biosynthetic operon was genetically disrupted...
October 12, 2016: Cell Host & Microbe
Khaled Abdallah, Katharina Hartman, Daniel Pletzer, Daria Zhurina, Matthias S Ullrich
Synthesis of the exopolysaccharide levan occurs in the bacterial blight pathogen of soybean, Pseudomonas syringae pv. glycinea PG4180, when this bacterium encounters moderate to high concentrations of sucrose inside its host plant. The process is mediated by the temperature-dependent expression and secretion of two levansucrases, LscB and LscC. Previous studies showed the importance of a prophage-associated promoter element in driving the expression of levansucrase genes. Herein, heterologous screening for transcriptional activators revealed that the prophage-borne transcriptional regulator, LscR, from P...
September 24, 2016: Molecular Microbiology
Theodore J Kottom, Deanne M Hebrink, Paige E Jenson, Jorge H Ramirez-Prado, Andrew H Limper
N-acetylglucosamine (GlcNAc), serves as an essential structural sugar on the cell surface of organisms. For example, GlcNAc is a major component of bacterial peptidoglycan, it is an important building block of fungal cell walls, including a major constituent of chitin and mannoproteins, and it also required for extracellular matrix generation by animal cells. Herein, we provide evidence for a uridine diphospho-N-acetylglucosamine (UDP-GlcNAc) pathway in Pneumocystis species. Using in silico search of the P...
September 15, 2016: American Journal of Respiratory Cell and Molecular Biology
André Vessoni Alexandrino, Leandro Seiji Goto, Maria Teresa Marques Novo-Mansur
Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), is a severe disease of citrus. Xcc presents broad spectrum of citrus hosts including economically important species whereas X. fuscans subsp. aurantifolii-type C (XauC) causes a milder disease and only infects Citrus aurantifolia. Trehalase catalyzes hydrolysis of the disaccharide trehalose, a sugar that has been reported to be related to Xcc pathogenicity. We expressed the recombinant gene product and assessed Xcc trehalase structural and kinetics data...
2016: PloS One
Monika Fraczek, Magdalena Hryhorowicz, Kamil Gill, Marta Zarzycka, Dariusz Gaczarzewicz, Piotr Jedrzejczak, Barbara Bilinska, Malgorzata Piasecka, Maciej Kurpisz
Bacterial semen inflammation/infection is an important diagnostic and therapeutic problem in contemporary andrology. The molecular mechanism by which inflammatory mediators compromise the fertilizing potential of germ cells is complex and multifactorial, and it remains unclear. To improve the understanding of the pathophysiology of human subfertility/infertility caused or complicated by reproductive tract inflammation/infection, we simultaneously evaluated a set of conventional (standard semen analysis) and nonconventional sperm parameters, including subcellular changes in sperm membranes (phospholipid scrambling, peroxidative damage, and phosphatidylserine (PS) externalization), mitochondria (mitochondrial transmembrane potential, ΔYm, and oxidoreductive capability), and DNA fragmentation in healthy young normozoospermic males with asymptomatic bacteriospermia and leukocytospermia...
August 17, 2016: Journal of Reproductive Immunology
Katarzyna Bocian, Jan Borysowski, Michał Zarzycki, Magdalena Pacek, Beata Weber-Dąbrowska, Maja Machcińska, Grażyna Korczak-Kowalska, Andrzej Górski
Bacteriophages (phages) are viruses of bacteria. Here we evaluated the effects of T4 and A3/R bacteriophages, as well as phage-generated bacterial lysates, on differentiation of human myeloid dendritic cells (DCs) from monocytes. Neither of the phages significantly reduced the expression of markers associated with differentiation of DCs and their role in the activation of T cells (CD40, CD80, CD83, CD86, CD1c, CD11c, MHC II, PD-L1, PD-L2, TLR2, TLR4, and CCR7) and phagocytosis receptors (CD64 and DEC-205). By contrast, bacterial lysate of T4 phage significantly decreased the percentages of DEC-205- and CD1c-positive cells...
2016: Frontiers in Microbiology
Natasha Bonilla, Maria Isabel Rojas, Giuliano Netto Flores Cruz, Shr-Hau Hung, Forest Rohwer, Jeremy J Barr
A major limitation with traditional phage preparations is the variability in titer, salts, and bacterial contaminants between successive propagations. Here we introduce the Phage On Tap (PoT) protocol for the quick and efficient preparation of homogenous bacteriophage (phage) stocks. This method produces homogenous, laboratory-scale, high titer (up to 10(10-11) PFU·ml(-1)), endotoxin reduced phage banks that can be used to eliminate the variability between phage propagations and improve the molecular characterizations of phage...
2016: PeerJ
Zhili Yao, Jessica M Mates, Alana M Cheplowitz, Lindsay P Hammer, Andrei Maiseyeu, Gary S Phillips, Mark D Wewers, Murugesan V S Rajaram, John M Robinson, Clark L Anderson, Latha P Ganesan
During Gram-negative bacterial infections, excessive LPS induces inflammation and sepsis via action on immune cells. However, the bulk of LPS can be cleared from circulation by the liver. Liver clearance is thought to be a slow process mediated exclusively by phagocytic resident macrophages, Kupffer cells (KC). However, we discovered that LPS disappears rapidly from the circulation, with a half-life of 2-4 min in mice, and liver eliminates about three quarters of LPS from blood circulation. Using microscopic techniques, we found that ∼75% of fluor-tagged LPS in liver became associated with liver sinusoidal endothelial cells (LSEC) and only ∼25% with KC...
September 15, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
Chloë De Witte, Christian Schulz, Annemieke Smet, Peter Malfertheiner, Freddy Haesebrouck
This article aimed to review the literature from 2015 dealing with gastric and enterohepatic non-Helicobacter pylori Helicobacter species (NHPH). A summary of the gastric microbiota interactions with H. pylori is also presented. An extensive number of studies were published during the last year and have led to a better understanding of the pathogenesis of infections with NHPH. These infections are increasingly reported in human patients, including infections with H. cinaedi, mainly characterized by severe bacteremia...
September 2016: Helicobacter
Alemu Tekewe, Yuanyuan Fan, Emilyn Tan, Anton P J Middelberg, Linda H L Lua
A high global burden of rotavirus disease and the unresolved challenges with the marketed rotavirus vaccines, particularly in the developing world, have ignited efforts to develop virus-like particle (VLP) vaccines for rotavirus. While rotavirus-like particles comprising multiple viral proteins can be difficult to process, modular VLPs presenting rotavirus antigenic modules are promising alternatives in reducing process complexity and cost. In this study, integrated molecular and bioprocess engineering approaches were used to simplify the production of modular murine polyomavirus capsomeres and VLPs presenting a rotavirus 18 kDa VP8* antigen...
August 6, 2016: Biotechnology and Bioengineering
Hwa Hui Shin, Byeong Hee Hwang, Hyung Joon Cha
Foodborne diseases caused by various pathogenic bacteria occur worldwide. To prevent foodborne diseases and minimize their impacts, it is important to inspect contaminated foods and specifically detect many types of pathogenic bacteria. Several DNA oligonucleotide biochips based on 16S rRNA have been investigated to detect bacteria; however, a mode of detection that can be used to detect diverse pathogenic strains and to examine the safety of food matrixes is still needed. In the present work, a 16S rRNA gene-derived geno-biochip detection system was developed after screening DNA oligonucleotide specific capture probes, and it was validated for multiple detection of 16 pathogenic strains that frequently occur with a signature pattern...
August 5, 2016: Biotechnology Journal
Ralf-Bernhardt Rues, Erik Henrich, Coilin Boland, Martin Caffrey, Frank Bernhard
The complexity of membrane protein synthesis is largely reduced in cell-free systems and it results into high success rates of target expression. Protocols for the preparation of bacterial lysates have been optimized in order to ensure reliable efficiencies in membrane protein production that are even sufficient for structural applications. The open accessibility of the semisynthetic cell-free expression reactions allows to adjust membrane protein solubilization conditions according to the optimal folding requirements of individual targets...
2016: Methods in Molecular Biology
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