Microbiological food safety assessment of high hydrostatic pressure processing: A review

Author: Rendueles, E.; Omer, M.K.; Alvseike, O.; Alonso-Calleja, C.; Capita, R.; Prieto, M. Description: High hydrostatic pressure (HHP) processing as a novel non-thermal method has shown great potential in producing microbiologically safer products while maintaining the natural characteristics of the food items. Scientific research of the process and its industrial applications has been widespread in the past two decades with many scientific publications describing its uses, advantages and limitations. The review describes the effect of HHP on foodborne pathogenic microorganisms, their structures and adaptive mechanisms, the intrinsic and extrinsic factors…

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Molecular mechanisms of antibiotic resistance

Author: Blair, J.M.A.; Webber, M.A.; Baylay, A.J.; Ogbolu, D.O.; Piddock, L.J.V. Description: Antibiotic-resistant bacteria that are difficult or impossible to treat are becoming increasingly common and are causing a global health crisis. Antibiotic resistance is encoded by several genes, many of which can transfer between bacteria. New resistance mechanisms are constantly being described, and new genes and vectors of transmission are identified on a regular basis. This article reviews recent advances in our understanding of the mechanisms by which bacteria are either intrinsically resistant or acquire resistance to antibiotics, including…

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Efficacy of Listerine, Meridol and chlorhexidine mouthrinses on plaque, gingivitis and plaque bacteria vitality

Author: Brecx, M.; Netuschil, L.; Reichert, B.; Schreil, G. Description: The experimental gingivitis model was used to compare the anti-plaque, anti-gingivitis and anti-microbial efficacies of a phenolic compound (Listerine) and an amine/stannous fluoride mouthwash (Meridol), using a placebo preparation as negative control and a chlorhexidine solution as positive control in a double-blind study. After professional toothcleaning, 36 volunteers performed optimal oral hygiene for a period of 2 weeks. They then ceased all oral hygiene procedures for 21 days during which they rinsed twice daily with 1 of the 4 mouthrinses….

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Efficacy of Listerine, Meridol and chlorhexidine mouthrinses on plaque, gingivitis and plaque bacteria vitality

Author: Brecx, M.; Netuschil, L.; Reichert, B.; Schreil, G. Description: The experimental gingivitis model was used to compare the anti-plaque, anti-gingivitis and anti-microbial efficacies of a phenolic compound (Listerine) and an amine/stannous fluoride mouthwash (Meridol), using a placebo preparation as negative control and a chlorhexidine solution as positive control in a double-blind study. After professional toothcleaning, 36 volunteers performed optimal oral hygiene for a period of 2 weeks. They then ceased all oral hygiene procedures for 21 days during which they rinsed twice daily with 1 of the 4 mouthrinses….

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Why is Deinococcus radiodurans so resistant to ionizing radiation?

Author: Battista, J.R.; Earl, A.M.; Park, M.J. Description: When exponential-phase cultures of Deinococcus radiodurans are exposed to a 5000-Gray dose of gamma radiation, individual cells suffer massive DNA damage. Despite this insult to their genetic integrity, these cells survive without loss of viability or evidence of mutation, repairing the damage by as-yet-poorly-understood mechanisms. Subject headings: DNA Damage; DNA Replication; DNA, Bacterial/metabolism; Gamma Rays; Genome, Bacterial; Gram-Positive Cocci/genetics/growth & development/radiation effects; Radiation Tolerance; Recombination, Genetic Publication year: 1999 Journal or book title: Trends in Microbiology Volume: 7 Issue: 9 Pages: 362-365…

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Interplay between iron homeostasis and virulence: Fur and RyhB as major regulators of bacterial pathogenicity

Author: Porcheron, Gaelle; Dozois, Charles M. Description: In bacteria-host interactions, competition for iron is critical for the outcome of the infection. As a result of its redox properties, this metal is essential for the growth and proliferation of most living organisms, including pathogenic bacteria. This metal is also potentially toxic, making the precise maintenance of iron homeostasis necessary for survival. Iron acquisition and storage control is mediated in most bacteria by the global ferric uptake regulator (Fur) and iron-responsive small regulatory non-coding RNAs (RyhB in the model organism Escherichia coli)….

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The microbial ecology of permafrost

Author: Jansson, Janet K.; Tas, Neslihan Description: Permafrost constitutes a major portion of the terrestrial cryosphere of the Earth and is a unique ecological niche for cold-adapted microorganisms. There is a relatively high microbial diversity in permafrost, although there is some variation in community composition across different permafrost features and between sites. Some microorganisms are even active at subzero temperatures in permafrost. An emerging concern is the impact of climate change and the possibility of subsequent permafrost thaw promoting microbial activity in permafrost, resulting in increased potential for greenhouse-gas emissions….

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Systematics, distribution, and host specificity of grass endophytes

Author: Leuchtmann, A. Description: Clavicipitaceous endophytes (Ascomycetes) are distributed worldwide in many grasses and sedges forming a perennial and often mutualistic association with their hosts. Most endophytes appear to produce alkaloid toxins in infected plants. The high frequency of infection in many grasses and in certain grassland communities may indicate a selective advantage of infected over non-infected host plants due to their toxic effects on grazing animals and insects. Field observations and artificial inoculations of seedlings have demonstrated a high degree of specificity of most endophytes to their host plant,…

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High genetic variability and low local diversity in a population of arbuscular mycorrhizal fungi

Author: Koch, A.M.; Kuhn, G.; Fontanillas, P.; Fumagalli, L.; Goudet, J.; Sanders, I.R. Description: Arbuscular mycorrhizal fungi (AMF) are ecologically important root symbionts of most terrestrial plants. Ecological studies of AMF have concentrated on differences between species; largely assuming little variability within AMF species. Although AMF are clonal, they have evolved to contain a surprisingly high within-species genetic variability, and genetically different nuclei can coexist within individual spores. These traits could potentially lead to within-population genetic variation, causing differences in physiology and symbiotic function in AMF populations, a consequence that…

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Organization of genetic variation in individuals of arbuscular mycorrhizal fungi

Author: Pawlowska, T.E.; Taylor, J.W. Description: Arbuscular mycorrhizal (AM) fungi (Glomeromycota) are thought to be the oldest group of asexual multicellular organisms. They colonize the roots of most land plants, where they facilitate mineral uptake from the soil in exchange for plant-assimilated carbon. Cells of AM fungi contain hundreds of nuclei. Unusual polymorphism of ribosomal DNA observed in individual spores of AM fungi inspired a hypothesis that heterokaryosis–that is, the coexistence of many dissimilar nuclei in cells–occurs throughout the AM fungal life history. Here we report a genetic approach to…

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