Virulence And Gene Regulation

Pseudomonas comprises three volumes covering the biology of pseudomonads in a wide context, including the niches they inhabit, the taxonomic relations among members of this group, the molecular biology of gene expression in different niches and under different environmental conditions, the analysis of virulence traits in plants, animals and human pathogens as well as the determinants that make some strains useful for biotechnological applications and promotion of plant growth. There has been growing interest in pseudomonads and a particular urge to understand the biology underlying the complex metabolism of these ubiquitous microbes. These bacteria are capable of colonizing a wide range of niches, including the soil, the plant rhizosphere and phylosphere, and animal tissues; more recently they have attracted attention because of their capacity to form biofilms, a characteristic with potentially important medical and environmental implications. The three volumes cover the following topics: - Taxonomy, - Genomics, - Life styles, - Cell Architecture, - Virulence, - Regulation, - Macromolecules, - Alternative Respiratory Substrates, - Catabolism and Biotransformations. Pseudomonas will be of use to all researchers working on these bacteria, particularly those studying microbiology, plant crops, pathogenesis, and chemical engineering. Advanced students in biology, medicine and agronomy will also find these three volumes a valuable reference during their studies.

A comprehensive compendium of scholarly contributions relating to bacterial virulence gene regulation. • Provides insights into global control and the switch between distinct infectious states (e.g., acute vs. chronic). • Considers key issues about the mechanisms of gene regulation relating to: surface factors, exported toxins and export mechanisms. • Reflects on how the regulation of intracellular lifestyles and the response to stress can ultimately have an impact on the outcome of an infection. • Highlights and examines some emerging regulatory mechanisms of special significance. • Serves as an ideal compendium of valuable topics for students, researchers and faculty with interests in how the mechanisms of gene regulation ultimately affect the outcome of an array of bacterial infectious diseases.

During the past twenty years Listeria monocytogenes has emerged as one of the most intensely studied bacterial pathogens. New windows are constantly being opened into the complexity of host cell biology and the interplay of the signals connecting the various cells and organs involved in the host response. This volume includes research from studies at the molecular level on the pathogenesis of Listeria monocytogenes and the response of the host to its infections.

Bacteria in various habitats are subject to continuously changing environmental conditions, such as nutrient deprivation, heat and cold stress, UV radiation, oxidative stress, dessication, acid stress, nitrosative stress, cell envelope stress, heavy metal exposure, osmotic stress, and others. In order to survive, they have to respond to these conditions by adapting their physiology through sometimes drastic changes in gene expression. In addition they may adapt by changing their morphology, forming biofilms, fruiting bodies or spores, filaments, Viable But Not Culturable (VBNC) cells or moving away from stress compounds via chemotaxis. Changes in gene expression constitute the main component of the bacterial response to stress and environmental changes, and involve a myriad of different mechanisms, including (alternative) sigma factors, bi- or tri-component regulatory systems, small non-coding RNA’s, chaperones, CHRIS-Cas systems, DNA repair, toxin-antitoxin systems, the stringent response, efflux pumps, alarmones, and modulation of the cell envelope or membranes, to name a few. Many regulatory elements are conserved in different bacteria; however there are endless variations on the theme and novel elements of gene regulation in bacteria inhabiting particular environments are constantly being discovered. Especially in (pathogenic) bacteria colonizing the human body a plethora of bacterial responses to innate stresses such as pH, reactive nitrogen and oxygen species and antibiotic stress are being described. An attempt is made to not only cover model systems but give a broad overview of the stress-responsive regulatory systems in a variety of bacteria, including medically important bacteria, where elucidation of certain aspects of these systems could lead to treatment strategies of the pathogens. Many of the regulatory systems being uncovered are specific, but there is also considerable “cross-talk” between different circuits. Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria is a comprehensive two-volume work bringing together both review and original research articles on key topics in stress and environmental control of gene expression in bacteria. Volume One contains key overview chapters, as well as content on one/two/three component regulatory systems and stress responses, sigma factors and stress responses, small non-coding RNAs and stress responses, toxin-antitoxin systems and stress responses, stringent response to stress, responses to UV irradiation, SOS and double stranded systems repair systems and stress, adaptation to both oxidative and osmotic stress, and desiccation tolerance and drought stress. Volume Two covers heat shock responses, chaperonins and stress, cold shock responses, adaptation to acid stress, nitrosative stress, and envelope stress, as well as iron homeostasis, metal resistance, quorum sensing, chemotaxis and biofilm formation, and viable but not culturable (VBNC) cells. Covering the full breadth of current stress and environmental control of gene expression studies and expanding it towards future advances in the field, these two volumes are a one-stop reference for (non) medical molecular geneticists interested in gene regulation under stress.

The critically acclaimed laboratory standard for more than forty years, Methods in Enzymology is one of the most highly respected publications in the field of biochemistry. Since 1955, each volume has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now with more than 300 volumes (all of them still in print), the series contains much material still relevant today truly an essential publication for researchers in all fields of life sciences. Key Features * Presents alternatives to mammalian model systems * Discusses virulence and essential gene identification * Defines global gene expression

Plant pathogens are a major threat to food security all around the world. Virulence genes enable the pathogens to disease the host and pose threats. We study and computationally model the expression of virulence in pathogens. The pel genes, a major virulence factor in pectinolytic bacteria which infect plants and cause soft rot disease. The Pel enzymes released by the pathogen result in the maceration of tissue in crops and facilitate pathogenesis. We model the pel genes in our model organism Dickeya dadantii. We study pelD/E genes which encode proteins with similar enzymatic activities, but also share the same set of transcriptional regulators, thus raising the question of the benefit of this duplication and the specific role of these two genes. We model their expression with respect to the KdgR repressor and CRP activator. We develop a quantitative dynamic kinetic model of this process that reproduces the observed behavior of the two genes and explains their specific role in the infection. The regulatory part of the model is based on experimental values, and fitted kinetic parameters are subjected to systematic evaluation. The model is robust and has multiple applications for studying the pathogenesis of pectinolytic bacteria. In addition, we explore the instance of carbon catabolite repression observed during the regulation of virulence genes Dickeya dadantii. The novel antibiotic seconeolitsin is characterized in the gram negative model organism Dickeya dadantii. Growth kinetics and MIC studies are carried out. The variations in the level of supercoiling in the presence of seconeolitsin and novobiocin are quantified and analyzed. The effect of supercoiling on the expression of genes, especially the pelE gene is studied using the novel antibiotic seconeolitsin. The study explores the role of supercoiling as a gene regulator.

Many advances have been made in the last decade in the understanding of the computational principles underlying olfactory system functioning. Neuromorphic Olfaction is a collaboration among European researchers who, through NEUROCHEM (Fp7-Grant Agreement Number 216916)-a challenging and innovative European-funded project-introduce novel computing p