The opportunistic pathogen Pseudomonas aeruginosa offers a rich variety of biologically relevant topics to explore and serves as a model system to understand the interactions of Gram-negative bacteria with human hosts. The organism adapts readily to most environments. It has a large and variable genome with a great deal of metabolic potential. P. aeruginosa encodes a variety of regulatory systems to fine tune gene expression and integrate environmental signals. This organism can infect both plants and animals and produces a plethora of enzymes and factors that can overcome host defenses. Moreover, it has the ability to change between the states of a sedentary colonizer to an invasive and highly motile organism. Clinically, the bacterium is resistant to many antibiotics making it difficult to treat and impossible to eradicate from the lungs of patients with cystic fibrosis. Intrinsic antibiotic resistance combined with an armamentarium of tissue degradative enzymes makes it imperative to possess a comprehensive understanding of the biology, genetics and pathogenesis of this organism so that novel therapeutics based on virulence product neutralization can be designed and implemented. This Research Topics issue will be devoted to updating the current understanding of P. aeruginosa systems as they relate to its different lifestyles in different environments. The underlying theme is to provide broad overviews and to integrate protein structure-function and gene regulation as it relates to the biology of this bacterium.

Assembling the latest research by an international group of contributors, this volume covers the epidemiology, pathogenesis, clinical features, and control measures of this elusive microorganism. It will provide a deeper understanding of the pathogen to physicians and surgeons caring for patients infected, or at risk of becoming infected, with Pseudomonas Aeruginosa.

The growing body of information on bacteria pathogenic for humans, mammals and plants generated within the past ten years has shown the interesting conservation of newly identified genes that playa direct role in the pathogenic mechanism. In addition to these genes, there are also genes that confer host specificities and other traits important in pathogenesis on these pathogens. In this volume, we have organized the subject areas to best fit the concept on the way bacterial pathogens recognize, interact and invade the host, on the regulation of genes involved in virulence, on the genes involved in the elaboration of toxins and other pathogenic components such as iron sequestering proteins, and on the mechanisms of circumventing the host defense systems. These areas are divided into Sections. Section I covers the first step when the pathogen seeks its host, and Sections II through VI cover subsequent steps leading to pathogenesis while avoiding host defenses. We conclude this work with a chapter summarizing information on examples of virulence mechanisms that are highly conserved.

"In print, online, or on your mobile device, Principles and Practice of Pediatric Infectious Disease provides the comprehensive and actionable coverage you need to understand, diagnose, and manage the ever-changing, high-risk clinical problems caused by infectious diseases in children and adolescents. With new chapters, expanded and updated coverage, and increased worldwide perspectives, this authoritative medical reference offers the latest need-to-know information in an easily-accessible, high-yield format for quick answers and fast, effective intervention!"--Publisher's website.

Beginning with the germ theory of disease in the 19th century and extending through most of the 20th century, microbes were believed to live their lives as solitary, unicellular, disease-causing organisms . This perception stemmed from the focus of most investigators on organisms that could be grown in the laboratory as cellular monocultures, often dispersed in liquid, and under ambient conditions of temperature, lighting, and humidity. Most such inquiries were designed to identify microbial pathogens by satisfying Koch's postulates.3 This pathogen-centric approach to the study of microorganisms produced a metaphorical "war" against these microbial invaders waged with antibiotic therapies, while simultaneously obscuring the dynamic relationships that exist among and between host organisms and their associated microorganisms-only a tiny fraction of which act as pathogens. Despite their obvious importance, very little is actually known about the processes and factors that influence the assembly, function, and stability of microbial communities. Gaining this knowledge will require a seismic shift away from the study of individual microbes in isolation to inquiries into the nature of diverse and often complex microbial communities, the forces that shape them, and their relationships with other communities and organisms, including their multicellular hosts. On March 6 and 7, 2012, the Institute of Medicine's (IOM's) Forum on Microbial Threats hosted a public workshop to explore the emerging science of the "social biology" of microbial communities. Workshop presentations and discussions embraced a wide spectrum of topics, experimental systems, and theoretical perspectives representative of the current, multifaceted exploration of the microbial frontier. Participants discussed ecological, evolutionary, and genetic factors contributing to the assembly, function, and stability of microbial communities; how microbial communities adapt and respond to environmental stimuli; theoretical and experimental approaches to advance this nascent field; and potential applications of knowledge gained from the study of microbial communities for the improvement of human, animal, plant, and ecosystem health and toward a deeper understanding of microbial diversity and evolution. The Social Biology of Microbial Communities: Workshop Summary further explains the happenings of the workshop.

Peptides play a crucial role in many physiological processes including actions as neurotransmitters, hormones, and antibiotics. Research has shown their importance in such fields as neuroscience, immunology, pharmacology, and cell biology. The Handbook of Biologically Active Peptides presents, for the first time, this tremendous body of knowledge in the field of biologically active peptides in one single reference. The section editors and contributors represent some of the most sophisticated and distinguished scientists working in basic sciences and clinical medicine. The Handbook of Biologically Active Peptides is a definitive, all-encompassing reference that will be indispensable for individuals ranging from peptide researchers, to biochemists, cell and molecular biologists, neuroscientists, pharmacologists, and to endocrinologists. Chapters are designed to be a source for workers in the field and will enable researchers working in a specific area to examine other related areas with which they would not ordinarily be familiar.*Chapters are designed to be a source for workers in the field and will enable researchers working in a specific area to examine other related areas that they would not ordinarily be familiar.*Fascinating relationships described in the book include the presence of some peptides originally found in frog skin that persist in the human human and brain where they can affect food intake and obesity.