Antibiofilm Agents

This book provides a survey of recent advances in the development of antibiofilm agents for clinical and environmental applications. The fact that microbes exist in structured communities called biofilms has slowly become accepted within the medical community. We now know that over 80% of all infectious diseases are biofilm-related; however, significant challenges still lie in our ability to diagnose and treat these extremely recalcitrant infections. Written by experts from around the globe, this book offers a valuable resource for medical professionals seeking to treat biofilm-related disease, academic and industry researchers interested in drug discovery and instructors who teach courses on microbial pathogenesis and medical microbiology.

Throughout the biological world, bacteria thrive predominantly in surface-attached, matrix-enclosed, multicellular communities or biofilms, as opposed to isolated planktonic cells. This choice of lifestyle is not trivial, as it involves major shifts in the use of genetic information and cellular energy, and has profound consequences for bacterial physiology and survival. Growth within a biofilm can thwart immune function and antibiotic therapy and thereby complicate the treatment of infectious diseases, especially chronic and foreign device-associated infections. Modern studies of many important biofilms have advanced well beyond the descriptive stage, and have begun to provide molecular details of the structural, biochemical, and genetic processes that drive biofilm formation and its dispersion. There is much diversity in the details of biofilm development among various species, but there are also commonalities. In most species, environmental and nutritional conditions greatly influence biofilm development. Similar kinds of adhesive molecules often promote biofilm formation in diverse species. Signaling and regulatory processes that drive biofilm development are often conserved, especially among related bacteria. Knowledge of such processes holds great promise for efforts to control biofilm growth and combat biofilm-associated infections. This volume focuses on the biology of biofilms that affect human disease, although it is by no means comprehensive. It opens with chapters that provide the reader with current perspectives on biofilm development, physiology, environmental, and regulatory effects, the role of quorum sensing, and resistance/phenotypic persistence to antimicrobial agents during biofilm growth.

This book presents an overview of antimicrobial peptides (AMPs), their mechanisms of antimicrobial action, other activities, and various problems that must still be overcome regarding their clinical application. Divided into four major parts, the book begins with a general overview of AMPs (Part I), and subsequently discusses the various mechanisms of antimicrobial action and methods for researching them (Part 2). It then addresses a range of activities other than antimicrobial action, such as cell penetration, antisepsis, anticancer, and immunomodulatory activities (Part 3), and explores the prospects of clinical application from various standpoints such as the selective toxicity, design, and discovery of AMPs (Part 4). A huge number of AMPs have been discovered in plants, insects, and vertebrates including humans, and constitute host defense systems against invading pathogenic microorganisms. Consequently, many attempts have been made to utilize AMPs as antibiotics. AMPs could help to solve the urgent problem of drug-resistant bacteria, and are also promising with regard to sepsis and cancer therapy. Gathering a wealth of information, this book will be a bible for all those seeking to develop antibiotics, anti-sepsis, or anticancer agents based on AMPs.

To prevent bacterial adherence, invasion and infection, antimicrobials such as antibiotics are being used and vastly researched nowdays. Several factors such as natural selection, mutations in genes, the presence of efflux pumps, impermeability of the cell wall, structural changes in enzymes and receptors, biofilm formation, and quorum sensing cause microorganisms to develop resistance against antimicrobials. Isolates that synthesize extended spectrum-β-lactamases (ESBL), induced β-lactamases (IBL), carbapenamases, metallo-β-lactamases (MBLs), and New Delhi metallo-β-lactamases (NDM) have emerged. Determining virulence factors such as biofilms and the level of antimicrobial activities of antimicrobial agents alone and in combination with appropriate doses against microorganisms is very important for the diagnosis, inhibition, and prevention of microbial infection. The goal of this book is to provide information on all these topics.

In the pursuit of technological advancement in the field of biotechnology and pharmaceutical industries to counteract health issues, bacterial infections remain a major cause of morbidity and mortality. The ability of bacterial pathogens to form biofilms further agglomerates the situation by showing resistance to conventional antibiotics. To overcome this serious issue, bioactive metabolites and other natural products were exploited to combat bacterial infections and biofilm-related health consequences. Natural products exhibited promising results in vitro, however; their efficacy in in vivo conditions remain obscured due to their low-solubility, bioavailability, and biocompatibility issues. In this scenario, nanotechnological interventions provide a multifaceted platform for targeted delivery of bioactive compounds by slow and sustained release of drug-like compounds. The unique physico-chemical properties, biocompatibility and eco-friendly nature of bioinspired nanostructures has revolutionized the field of biology to eradicate microbial infections and biofilm-related complications. The green-nanotechnology based metal and metal oxide nanoparticles and polymeric nanoparticles have been regularly employed for antimicrobial and antibiofilm applications without causing damage to host tissues. The implications of these nanoparticles toward achieving sustainability in agriculture by providing systemic resistance against a variety of phytopathogens therefore plays crucial role in growth and crop productivity. Also the advent of smart and hybrid nanomaterials such as metal-based polymer nanocomposites, lipid-based nanomaterials and liposomes have the inherent potential to eradicate bacterial biofilm-related infections in an efficient manner. The recent development of carbon-based nanomaterials such as carbon nanotubes (CNTs) and silica based nanomaterials such as mesoporous silica nanoparticles (MSNs) also exploit a target of dreadful healthcare conditions such as cancer, immunomodulatory diseases, and microbial infections, as well as biofilm-related issues owing to their stability profile, biocompatibility, and unique physio-chemical properties. Recently novel physical approaches such as photothermal therapy (PTT) and antimicrobial photodynamic therapy (aPDT) also revolutionized conventional strategies and are engaged in eradicating microbial biofilm-related infections and related health consequences. These promising advancements in the development of novel strategies to treat microbial infections and biofilm-related multidrug resistance (MDR) phenomenon may provide new avenues and aid to conventional antimicrobial therapeutics.

This new book highlights some of the exciting research that has recently been done in the important and far-ranging field of biofilms and microbial agents. It discusses antimicrobial agents in relation to biofilm control and resistance. The book also introduces biofilm formation and mitigation strategies. It helps explores long-term solutions to the challenges imposed by biofilms.

This book examines biofilms in nature. Organized into four parts, this book addresses biofilms in wastewater treatment, inhibition of biofilm formation, biofilms and infection, and ecology of biofilms. It is designed for clinicians, researchers, and industry professionals in the fields of microbiology, biotechnology, ecology, and medicine as well as graduate and postgraduate students.

The Perfect Slime presents the latest state of knowledge and all aspects of the Extracellular Polymeric Substances, (EPS) matrix – from the ecological and health to the antifouling perspectives. The book brings together all the current material in order to expand our understanding of the functions, properties and characteristics of the matrix as well as the possibilities to strengthen or weaken it. The EPS matrix represents the immediate environment in which biofilm organisms live. From their point of view, this matrix has paramount advantages. It allows them to stay together for extended periods and form synergistic microconsortia, it retains extracellular enzymes and turns the matrix into an external digestion system and it is a universal recycling yard, it protects them against desiccation, it allows for intense communication and represents a huge genetic archive. They can remodel their matrix, break free and eventually, they can use it as a nutrient source. The EPS matrix can be considered as one of the emergent properties of biofilms and are a major reason for the success of this form of life. Nevertheless, they have been termed the “black matter of biofilms” for good reasons. First of all: the isolation methods define the results. In most cases, only water soluble EPS components are investigated; insoluble ones such as cellulose or amyloids are much less included. In particular in environmental biofilms with many species, it is difficult to impossible isolate, separate the various EPS molecules they are encased in and to define which species produced which EPS. The regulation and the factors which trigger or inhibit EPS production are still very poorly understood. Furthermore: bacteria are not the only microorganisms to produce EPS. Archaea, Fungi and algae can also form EPS. This book investigates the questions, What is their composition, function, dynamics and regulation? What do they all have in common?