Structural basis for transcription activation by Crl through tethering of {sigma}S and RNA polymerase Biochemistry

In bacteria, a primary σ-factor associates with the core RNA polymerase (RNAP) to control most transcription initiation, while alternative σ-factors are used to coordinate expression of additional regulons in response to environmental conditions. Many alternative σ-factors are negatively regulated by anti–σ-factors. In Escherichia coli, Salmonella enterica, and many other γ-proteobacteria,...
Source: Proceedings of the National Academy of Sciences - Category: Science Authors: Tags: Biological Sciences Source Type: research

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Publication date: Available online 13 October 2019Source: MycoscienceAuthor(s): Katesaraporn Nuankeaw, Boonyanoot Chaiyosang, Thanapat Suebrasri, Somdej Kanokmedhakul, Saisaamorn Lumyong, Sophon BoonlueAbstractBioactive compounds of endophytic fungus Trichoderma polyalthiae were extracted from culture broth media. The crude extracts showed strong antimicrobial activity against human pathogens. Biologically active compounds were isolated and purified by chromatographic methods. The structures of the pure compounds were elucidated by spectroscopic methods. They were identified as Violaceol I and Violaceol II. These compounds...
Source: Mycoscience - Category: Biology Source Type: research
Publication date: Available online 10 October 2019Source: Comparative Immunology, Microbiology and Infectious DiseasesAuthor(s): Bárbara Martín-Maldonado, Laura Montoro-Dasi, Maria Teresa Pérez-Gracia, Jaume Jordá, Santiago Vega, Francisco Marco-Jiménez, Clara MarinAbstractWild birds have repeatedly been found to be involved in the dissemination of enteric bacterial pathogens in the environment. The aim of this study was to determine the occurrence of Salmonella and Campylobacter as well as the antimicrobial resistance in wild Bonelli’s eagles nestlings in Eastern Spain. In addition...
Source: Comparative Immunology, Microbiology and Infectious Diseases - Category: Infectious Diseases Source Type: research
Publication date: Available online 10 October 2019Source: Comparative Immunology, Microbiology and Infectious DiseasesAuthor(s): Rasha M.A. Gharieb, Elshaima M. Fawzi, Ibrahim ElsohabyAbstractAntimicrobial resistance profile of E. coli and Salmonella serovars isolated from diarrheic calves and handlers in Egypt is unknown due to the absence of monitoring. Therefore, this study aimed to determine the virulence, genetic and antimicrobial resistance profiles of E. coli and Salmonella serovars associated with diarrhea in calves and handlers in intensive dairy farms in Egypt. A total of 36 bacterial strains (20 E. coli and 16 S...
Source: Comparative Immunology, Microbiology and Infectious Diseases - Category: Infectious Diseases Source Type: research
Microcins are low-molecular-weight, ribosomally produced, highly stable, bacterial-inhibitory molecules involved in competitive, and amensalistic interactions between Enterobacteriaceae in the intestine. These interactions take place in a highly complex chemical landscape, the intestinal eco-active chemosphere, composed of chemical substances that positively or negatively influence bacterial growth, including those originated from nutrient uptake, and those produced by the action of the human or animal host and the intestinal microbiome. The contribution of bacteria results from their effect on the host generated molecules...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Abstract Salmonella enterica are natural bacterial pathogens of humans and animals that cause systemic infection or gastroenteritis. During systemic infection, Salmonella generally reside within professional phagocytes, typically macrophages, whereas gastroenteritis is caused by infection of epithelial cells. We are only beginning to understand which host pathways contribute to Salmonella survival in particular cell types. We therefore sought to identify compounds that perturb Salmonella-host interactions using a chemical genetics approach. We found one small molecule, D61, that reduces Salmonella load in cell-lin...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research
Publication date: January 2020Source: LWT, Volume 117Author(s): Gökhan Kürşad İncili, Pınar Karatepe, Osman İrfan İlhakAbstractThe aim of this study was to determine the single and combined effect of chitosan and Pediococcus acidilactici (B-LC-20) on Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes in meatballs. After spiking the samples with pathogens, meatball mixture was divided into 4 groups as control, chitosan, B-LC-20 and chitosan + B-LC-20. Subsequently, chitosan (0.4%) and P. acidilactici (6.73 log10) was added into the treatment groups. P. acidilactici effective...
Source: LWT Food Science and Technology - Category: Food Science Source Type: research
Publication date: Available online 3 October 2019Source: Food HydrocolloidsAuthor(s): Hossein Haghighi, Serge Kameni Leugoue, Frank Pfeifer, Heinz Wilhelm Siesler, Fabio Licciardello, Patrizia Fava, Andrea PulvirentiAbstractThe main aim of this study was to characterize microstructural, physical, optical, mechanical, water barrier and antimicrobial properties of chitosan-polyvinyl alcohol blend films (CS-PVA) enriched with ethyl lauroyl arginate (LAE) (1–10% w/v) for food packaging applications. The film microstructure was determined by scanning electron microscopy. Active films containing 10% LAE showed cracks on th...
Source: Food Hydrocolloids - Category: Food Science Source Type: research
In this study, two new and one previously reported mixed ligand Cu(II) complexes were synthesized and characterized. The complexes have general formula [Cu(L1)(L2)]ClO4 in which L1 is an NN'O type unsymmetrical tridentate Schiff base ligand and L2 is an N-donor heterocyclic ligand, i.e. 2,2′-bipyridine in complex (2), 4,4′-di-t-butyl-2,2′-bipyridine in (3) and 1,10-phenanthroline in (4). The Schiff base ligand is the mono-condensed form of the reaction between ethylenediamine with salicylaldehyde. The complexes were characterized by IR and UV-Vis spectroscopy, as well as elemental analyses. Crystal struct...
Source: Inorganica Chimica Acta - Category: Chemistry Source Type: research
Dairy manure, a by-product in the dairy industry, is also a potential source of nutrients for crops. However, improper application of biological soil amendments of animal origin can be a source of contamination with enteric foodborne pathogens. A 2-year field study was conducted to evaluate impacts of dairy manure fertilizer application on the microbial safety of red raspberry (Rubus idaeus L) production. Fertilizers, including a standard synthetic fertilizer (CON), straight lagoon raw manure (SL), anaerobically digested liquid effluent (DLE), compost (COM) and dairy manure-derived refined fertilizers including ammonium su...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In this study, three replicates of manure and digestate were collected from five farm biogas plants receiving animal manure in order to assess the occurrence and concentrations of sporulating (Clostridium botulinum,Clostridioides difficile,Clostridium perfringens) and nonsporulating (Listeria monocytogenes, thermotolerantCampylobacter spp.,Salmonella,Escherichia coli, enterococci) bacteria. Concentrations ofE. coli, enterococci, andC. perfringens in digestates ranged from 102 to 104, 104 to 105, and
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research
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