Regulation Of Gene Expression In Enteropathogenic Bacteria Volume Ii

Following the success of this Research Topic http://journal.frontiersin.org/ researchtopic/3298/regulation-of-gene-expression-in-enteropathogenic-bacteria, we are happy to launch a second edition of the project. Pathogenic bacteria have evolved numerous strategies to survive in and to attack hosts, which can be reflected by transcriptional and posttranscriptional changes in specific genes especially including those encoding virulence determinants. Regulation of gene expression by regulatory proteins and non-coding RNAs enables the pathogens to adapt their metabolic needs and to coordinately express virulence determinants during different stages of infection.

Gram-negative Escherichia coli (E. coli) bacteria are the most numerous commensal aerobic germs located in the human colon. Diarrhea caused by E. coli pathogenic strains is a major cause of death in developing countries, especially the sub-Saharan and South Asian areas. Some strains cause diarrhea, and all of them may produce an infectious disease. This book includes ten chapters covering the main aspects of infections related to E. coli, their pathogenic mechanisms, treatments, and resistance to diverse antibiotics.

Many bacterial diseases are caused by organisms growing together as communities or biofilms. These microorganisms have the capacity to coordinately regulate specific sets of genes by sensing and communicating amongst themselves utilizing a variety of signals. This book examines the mechanisms of quorum sensing and cell-to-cell communication in bacteria and the roles that these processes play in regulating virulence, bacterial interactions with host tissues, and microbial development. Recent studies suggest that microbial cell-to-cell communication plays an important role in the pathogenesis of a variety of disease processes. Furthermore, some bacterial signal molecules may possess immunomodulatory activity. Thus, understanding the mechanisms and outcomes of bacterial cell-to-cell communication has important implications for appreciating host-pathogen interactions and ultimately may provide new targets for antimicrobial therapies that block or interfere with these communication networks.

A critical factor for bacterial survival in any environment is the ability to sense and respond appropriately to insults that cause stress to the cell, threatening its survival. Most of these stressors first affect the outer surface of the bacterial cell, are sensed in some way, and defense measures are enacted in response. If the bacteria successfully respond to an encountered stress, they survive and multiply. If they are unsuccessful or inefficient in their response, it can result in death. Efficiently responding to factors that induce stress is especially important for bacteria that inhabit environments that are constantly changing, or for those that inhabit more than one biological niche. In addition, bacterial species that associate with humans and other organisms must be able to overcome stresses that are produced by the host immune response in order to colonize and cause disease. The wide variety of stressors encountered by bacteria has resulted in countless strategies that are used by pathogens to overcome these insults, which we continue to identify. Clearly, a better understanding of these stress response mechanisms may be useful for developing new strategies to combat bacteria that cause certain infectious diseases. This Research Topic aims to highlight our increasing understanding of mechanisms by which bacteria sense and respond to stresses encountered in the host or other environments. Examples of stress response mechanisms of interest include, but are not limited to those that respond to antimicrobials, host immune responses, or environmental changes.

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.

ECAB Health Impact of Probiotics: Vision & Opportunities - E-Book

After thirty years, PPID is still the reference of choice for comprehensive, global guidance on diagnosing and treating the most challenging infectious diseases. Drs. Mandell, Bennett, and Dolin have substantially revised and meticulously updated, this new edition to save you time and to ensure you have the latest clinical and scientific knowledge at your fingertips. With new chapters, expanded and updated coverage, increased worldwide perspectives, and many new contributors, Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, 7th Edition helps you identify and treat whatever infectious disease you see. Consult this title on your favorite e-reader, conduct rapid searches, and adjust font sizes for optimal readability. Compatible with Kindle®, nook®, and other popular devices. Get the answers to questions you have with more in-depth coverage of epidemiology, etiology, pathology, microbiology, immunology, and treatment of infectious agents than you’ll find in any other infectious disease resource. Find the latest diagnoses and treatments for currently recognized and newly emerging infectious diseases, such as those caused by avian and swine influenza viruses. Put the latest knowledge to work in your practice with new or completely revised chapters on influenza (new pandemic strains); new Middle East respiratory syndrome (MERS) virus; probiotics; antibiotics for resistant bacteria; antifungal drugs; new antivirals for hepatitis B and C; Clostridium difficile treatment; sepsis; advances in HIV prevention and treatment; viral gastroenteritis; Lyme disease; Helicobacter pylori; malaria; infections in immunocompromised hosts; immunization (new vaccines and new recommendations); and microbiome. Benefit from fresh perspectives and global insights from an expanded team of international contributors. Find and grasp the information you need easily and rapidly with newly added chapter summaries. These bulleted templates include diagnosis, therapy, and prevention and are designed as a quick summary of the chapter and to enhance relevancy in search and retrieval on Expert Consult. Stay current on Expert Consult with a thorough and regularly scheduled update program that ensures access to new developments in the field, advances in therapy, and timely information. Access the information you need easily and rapidly with new succinct chapter summaries that include diagnosis, therapy, and prevention. Experience clinical scenarios with vivid clarity through a richly illustrated, full-color format that includes 1500 photographs for enhanced visual guidance.