Introduction: Extracorporeal blood purification systems represent a promising alternative for treatment of blood stream infections with multiresistant bacteria.
Objectives: The aim of this study was to analyse the binding activity of S. aureus to Seraph affinity filters based on heparin coated beads and to identify effectors influencing this binding activity.
Strategically located at mucosal sites, mast cells are instrumental in sensing invading pathogens and modulating the quality of the ensuing immune responses depending on the nature of the infecting microbe. It is believed that mast cells produce type I IFN (IFN-I) in response to viruses, but not to bacterial infections, because of the incapacity of bacterial pathogens to internalize within mast cells, where signaling cascades leading to IFN-I production are generated. However, we have previously reported that, in contrast with other bacterial pathogens, can internalize into mast cells and therefore could trigger a unique response.
View Article and Find Full Text PDFInfections by the pathogenic gut bacterium Clostridioides difficile cause severe diarrhoeas up to a toxic megacolon and are currently among the major causes of lethal bacterial infections. Successful bacterial propagation in the gut is strongly associated with the adaptation to changing nutrition-caused environmental conditions; e.g.
View Article and Find Full Text PDFMicrob Biotechnol
January 2021
This Crystal Ball speculates on the potential of molecular decoys for prevention and therapy in infectious diseases. It is dedicated to the memory of Singh Chhatwal, who pioneered research on disguises and decoys produced by Streptococcus, and so much more.
View Article and Find Full Text PDFInfections involving biofilms are difficult to treat due to increased resistances against antibiotics and the immune system. Hence, there is an urgent demand for novel drugs against biofilm infections. During our search for novel biofilm inhibitors from fungi, we isolated linoleic acid from the ascomycete which showed biofilm inhibition of several bacteria at sub-MIC concentrations.
View Article and Find Full Text PDFsubsp. () is an opportunistic pathogen of several species including humans. is found on mucus membranes of healthy horses, but can cause acute and chronic endometritis.
View Article and Find Full Text PDFUnlabelled: Oxidative phosphorylation using multiple-component, membrane-associated protein complexes is the most effective way for a cell to generate energy. Here, we systematically investigated the multiple protein-protein interactions of the denitrification apparatus of the pathogenic bacterium Pseudomonas aeruginosa During denitrification, nitrate (Nar), nitrite (Nir), nitric oxide (Nor), and nitrous oxide (Nos) reductases catalyze the reaction cascade of NO(3-)→ NO(2-)→ NO → N2O → N2 Genetic experiments suggested that the nitric oxide reductase NorBC and the regulatory protein NosR are the nucleus of the denitrification protein network. We utilized membrane interactomics in combination with electron microscopy colocalization studies to elucidate the corresponding protein-protein interactions.
View Article and Find Full Text PDFChemical activities of hydrophobic substances can determine the windows of environmental conditions over which microbial systems function and the metabolic inhibition of microorganisms by benzene and other hydrophobes can, paradoxically, be reduced by compounds that protect against cellular water stress (Bhaganna et al. in Microb Biotechnol 3:701-716, 2010; Cray et al. in Curr Opin Biotechnol 33:228-259, 2015a).
View Article and Find Full Text PDFUnlabelled: Pseudomonas aeruginosa is a ubiquitously occurring environmental bacterium and opportunistic pathogen responsible for various acute and chronic infections. Obviously, anaerobic energy generation via denitrification contributes to its ecological success. To investigate the structural basis for the interconnection of the denitrification machinery to other essential cellular processes, we have sought to identify the protein interaction partners of the denitrification enzyme nitrite reductase NirS in the periplasm.
View Article and Find Full Text PDFHuman β-defensins are host defense peptides performing antimicrobial as well as immunomodulatory functions. The present study investigated whether treatment of Escherichia coli with human β-defensin 2 could generate extracellular molecules of relevance for immune regulation. Mass spectrometry analysis of bacterial supernatants detected the accumulation of purine nucleosides triggered by β-defensin 2 treatment.
View Article and Find Full Text PDFEnvironmental microbes oscillate between feast and famine and need to carefully manage utilization, storage and conversion of reserve products to exploitable sources of carbon and energy. Polyhydroxyalkanoates (PHAs) are storage polymers that serve bacteria as sources of food materials under physiological conditions of carbon demand. In order to obtain insights into the role of PHA depolymerase (PhaZ) and its relationship to a PHA polymerase (PhaC2) in the carbon management activity of Pseudomonas putida strain U, we created a polymerase hyperexpression strain and a depolymerase knockout mutant of this strain, and examined their synthesis of PHA and expression of their PHA genes.
View Article and Find Full Text PDFNatural products and their derivatives have been and continue to be rich sources for drug discovery. However, natural products are not drugs. They are produce in nature and through biological assays they are identified as leads, which become candidates for drug development.
View Article and Find Full Text PDFThe cyclodepsipeptide serratamolide A ( 1) and five closely related compounds together with three new glucosamine derivatives were isolated by bioactivity-guided chromatography from the XAD adsorber resin extract of a Serratia sp. The structures of the compounds were elucidated by 2D NMR and MS analyses. In addition to the known serratamolide A ( 1) with two C 10 alkyl chains, its derivatives always contained one C 10 chain combined with either C 12:1, C 12, C 11, C 9, or C 8 chains.
View Article and Find Full Text PDFThe C3stau2 exoenzyme from Staphylococcus aureus is a C3-like ADP-ribosyltransferase which possesses no specific receptor-binding domain or translocation unit required for entry in target cells where its substrate is located. Here we show that C3stau2 can reach its target after invasion of staphylococci in eukaryotic cells without needing translocation.
View Article and Find Full Text PDFAntimicrob Agents Chemother
May 2006
We report here the discovery, isolation, and chemical and preliminary biological characterization of a new antibiotic compound, 7-O-malonyl macrolactin A (MMA), produced by a Bacillus subtilis soil isolate. MMA is a bacteriostatic antibiotic that inhibits a number of multidrug-resistant gram-positive bacterial pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and a small-colony variant of Burkholderia cepacia. MMA-treated staphylococci and enterococci were pseudomulticellular and exhibited multiple asymmetric initiation points of septum formation, indicating that MMA may inhibit a cell division function.
View Article and Find Full Text PDFBiliary stents inserted to relieve obstructive jaundice caused by biliary or pancreatic malignancies inevitably become occluded by microbial growth in the form of diverse microbial community biofilms. The scarce information available on these communities is based on cultivation methods, but such methods usually provide distorted overviews of community composition, so commonalities and differences in biliary stent communities are uncertain. We extracted DNA and RNA from the microbial communities of 11 biliary stents explanted from nine patients in hospitals from two different countries, amplified 16S rRNA and rDNA sequences, analysed the amplicons by the single-strand conformation polymorphism (SSCP) method, and sequenced and deduced phylogenetic assignments of the major amplicons representing the major biofilm community members.
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