Histones, HMG, HU, IHF: Meme combat

Oberto, J., Drlica, K., Rouviere-Yaniv, J. (1994) Biochimie, 76(10-11), 901-908 In this review article, we present a compilation of the proteins homologous to Escherichia coli HU: the HU-like family. Two of these, HU and IHF from E coli have been extensively characterized genetically and biochemically. Due to their DNA binding activities, these proteins confer a condensed shape to the chromosome and regulate the transcription of selected sets of its genes. The parallel between the dual function of the HU-like proteins and the roles described for eukaryotic histone and HMG proteins…

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Inhibitory effect of Cinnamomum cassia oil on non-O157 Shiga toxin-producing Escherichia coli

Author: Sheng, L.; Zhu, M.-J. Description: Shiga toxin-producing Escherichia coli (STEC) have caused numerous foodborne outbreaks. Compared with the most well-known STEC E. coli O157:H7, importance of non-O157 STEC has been underestimated and they have gained far less attention till increasing outbreaks recently. Using natural plant materials as antimicrobial agents is a heated area. Therefore in this study, Cinnamomum cassia, a widely used spice in cuisine, was tested for its antibacterial efficacy on CDC “top six” non-O157 STECs including O26, O45, O103, O111, O121, O145. Gas chromatography-mass spectrometry analysis showed…

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Antibacterial properties of nine pure metals: a laboratory study using Staphylococcus aureus and Escherichia coli

Author: Yasuyuki, M.; Kunihiro, K.; Kurissery, S.; Kanavillil, N.; Sato, Y.; Kikuchi, Y. Description: Bacterial attachment and growth on material surfaces are considered to be the primary steps leading to the formation of biofilm. Biofilms in hospital and food processing settings can result in bacterial infection and food contamination, respectively. Prevention of bacterial attachment, therefore, is considered to be the best strategy for abating these menaces and therefore the development of antibacterial metals becomes important. In this study, nine pure metals, viz. titanium, cobalt, nickel, copper, zinc, zirconium, molybdenum, tin,…

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The Escherichia coli divisome: born to divide

Author: Natale, P.; Pazos, M.; Vicente, M. Description: Septation in Escherichia coli involves complex molecular mechanisms that contribute to the accuracy of bacterial division. The proto-ring, a complex made up by the FtsZ, FtsA and ZipA proteins, forms at the beginning of the process and directs the assembly of the full divisome. Central to this complex is the FtsZ protein, a GTPase able to assemble into a ring-like structure that responds to several modulatory inputs including mechanisms to position the septum at midcell. The connection with the cell wall synthesising…

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Effect of environmental factors and cell physiological state on Pulsed Electric Fields resistance and repair capacity of various strains of Escherichia coli

Author: Somolinos, M.; Garcia, D.; Manas, P.; Condon, S.; Pagan, R. Description: The aim was to determine the resistance variation of four strains of Escherichia coli to Pulsed Electric Fields (PEF), the role of the sigma factor RpoS in PEF resistance, as well as the influence of several environmental factors and the cell physiological state on the PEF resistance and repair capacity. The rpoS null mutant, E. coli BJ4L1, exhibited decreased PEF resistance as compared with its wild-type parent, BJ4. W3110 and O157:H7 were the most PEF-resistant strains: whereas 2…

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Evolution of Escherichia coli for growth at high temperatures

Author: Rudolph, B.; Gebendorfer, K.M.; Buchner, J.; Winter, J. Description: Evolution depends on the acquisition of genomic mutations that increase cellular fitness. Here, we evolved Escherichia coli MG1655 cells to grow at extreme temperatures. We obtained a maximum growth temperature of 48.5 degrees C, which was not increased further upon continuous cultivation at this temperature for >600 generations. Despite a permanently induced heat shock response in thermoresistant cells, only exquisitely high GroEL/GroES levels are essential for growth at 48.5 degrees C. They depend on the presence of lysyl-tRNA-synthetase, LysU, because…

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Pathogenic Escherichia coli

Author: Kaper, James B.; Nataro, James P.; Mobley, Harry L. Description: Few microorganisms are as versatile as Escherichia coli. An important member of the normal intestinal microflora of humans and other mammals, E. coli has also been widely exploited as a cloning host in recombinant DNA technology. But E. coli is more than just a laboratory workhorse or harmless intestinal inhabitant; it can also be a highly versatile, and frequently deadly, pathogen. Several different E. coli strains cause diverse intestinal and extraintestinal diseases by means of virulence factors that affect…

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Mutations in a temperate bacteriophage affecting its ability to lysogenize Escherichia coli

Author: Kaiser, A.D. Description: Forty independently occurring clear plaque-forming mutants of A have been isolated. Among them three different phenotypes can be recognized. Crosses between mutants indicate that all of the mutant loci are closely linked to one another, occupying a segment of the A linkage group which is about of the total known genetic length. More detailed mapping reveals that the mutant loci fall into three adjacent regions, one for each phenotype. Mixed infection with a pair of phenotypically different mutants, each of which lysogenizes very poorly or not…

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Rapid detection of Escherichia coli using bacteriophage-induced lysis and image analysis

Author: Yang, X.; Wisuthiphaet, N.; Young, G. M. & Nitin, N. Description: Rapid detection of bacterial pathogens is a critical unmet need for both food and environmental samples such as irrigation water. As a part of the Food safety Modernization Act (FSMA), The Produce Safety rule has established several requirements for testing for the presence of generic Escherichia coli in water, but the current method available for testing (EPA M1603) demands specified multiple colony verification and highly trained personnel to perform these tests. The purpose of the study was to…

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Induced expression of the heat shock protein genes uspA and grpE during starvation at low temperatures and their influence on thermal resistance of Escherichia coli O157:H7

Author: Zhang, Y.; Griffiths, M.W. Description: Heat shock proteins play an important role in protecting bacterial cells against several stresses, including starvation. In this study, the promoters for two genes encoding heat shock proteins involved in many stress responses, UspA and GrpE, were fused with the green fluorescent protein (gfp) gene. Thus, the expression of the two genes could be quantified by measuring the fluorescence emitted by the cells under different environmental conditions. The heat resistance levels of starved and nonstarved cells during storage at 5, 10, and 37 degrees…

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