Biofilm Formation By Staphylococci And Streptococci Structural Functional And Regulatory Aspects And Implications For Pathogenesis

Members of the genus Staphylococcus and Streptococcus are the causative agnets of many human and animal diseases. Over the past decade the complete sequencing of many staphylococcal and streptococcal genomes has promoted a significant advance in our knowledge of these important pathogens. The pathogenicity of these bacteria is due to the expression of a large variety of virulence factors. Such determinants, which are cell wall-associated and secreted proteins, include adhesins that confer to the pathogen the ability to attach to extracellular matrix/plasma and host cell surfaces, proteins that contribute to host cell invasion and intracellular survival and soluble factors that decrease phagocytosis and modulate the immune response. Furthermore, these Gram-positive cocci in many natural environments (heart valve, lung, oral cavity, throat) and infections on implanted devices live in matrix-encased groups known as biofilms. Biofilms are specialized bacterial communities with high order organization analogous to that of a tissue in multicellular organism that adhere to abiotic or biological substrata and produce an exopolymeric matrix composed of polysaccarides, proteins, DNA or combination thereof. Bacteria within a biofilm persist in adverse conditions, show resistance to killing by antibiotics and to host immune defences and are difficult to eradicate and treat clinically. Therefore, understanding the mechanisms of biofilm development will allow us to effectively combat staphylococcal/streptococcal biofilm-based infections. This Research Topic will focus on the molecular components involved in biofilm formation by staphylococci and streptococci, the role they play in the development, maturation and dispersal of biofilm and on the regulatory aspects of such complex processes. The implication for the pathogenesis of infective diseases and potential therapeutic strategies against biofilm-based infections will be also discussed. The articles will highlight both the recent advances and future challenges inherent in this rapidly evolving area.

This book highlights treatment strategies for bacterial biofilms in connection with a variety of human diseases. In particular, it reviews bacterial biofilm formation and its mechanism. Topics covered include biofilms in human health, the role of biofilms in mediating human diseases, and methods for testing bacterial biofilms. Further sections concentrate on biofilm-mediated diseases in different parts of the human gastrointestinal tract, while therapeutic strategies for biofilm control and natural agents that disrupt bacterial biofilms are also covered. Readers will also find the latest advances in probiotics and biofilms, as well as the use of probiotics to counteract biofilm-associated infections. Biofilms and antimicrobial resistance are discussed. Subsequent chapters address the management of inflammatory bowel disease via probiotics biofilms, as well as the role of probiotics bacteria in the treatment of human diseases associated with bacterial biofilms. The book is chiefly intended for clinicians/scientists in the fields of medical microbiology, applied microbiology, biochemistry, and biotechnology.

This book provides ample knowledge and better understanding of Streptococcus pyogenes and their superantigens. Many illustrations make this a highly informative book. This book elucidates briefly Streptococcus pyogenes as a strict human pathogen possessing an array of virulence factors. These help in evading host immune responses such as by the activation of non-specific T-cell subpopulations by producing superantigens. This book mainly focuses on streptococcal superantigens and explains how they are different from conventional antigens. Moreover, it elaborates those diseases in which superantigens are actively involved. Useful aspects of superantigens and different therapeutic interventions to eradicate superantigens induced diseased are also discussed.

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 will cover both the evidence for biofilms in many chronic bacterial infections as well as the problems facing these infections such as diagnostics and treatment regimes. A still increasing interest and emphasis on the sessile bacterial lifestyle biofilms has been seen since it was realized that that less than 0.1% of the total microbial biomass lives in the planktonic mode of growth. The term was coined in 1978 by Costerton et al. who defined the term biofilm for the first time.In 1993 the American Society for Microbiology (ASM) recognised that the biofilmmode of growth was relevant to microbiology. Lately many articles have been published on the clinical implications of bacterial biofilms. Both original articles and reviews concerning the biofilm problem are available.

Established almost 30 years ago, Methods in Microbiology is the most prestigious series devoted to techniques and methodology in the field. Now totally revamped, revitalized, with a new format and expanded scope, Methods in Microbiology will continue to provide you with tried and tested, cutting-edge protocols to directly benefit your research. Focuses on the methods most useful for the microbiologist interested in the way in which bacteria cause disease Includes section devoted to 'Approaches to characterising pathogenic mechanisms' by Stanley Falkow Covers safety aspects, detection, identification and speciation Includes techniques for the study of host interactions and reactions in animals and plants Describes biochemical and molecular genetic approaches Essential methods for gene expression and analysis Covers strategies and problems for disease control

Staphylococci remain the most important cause of hospital-acquiredinfections in the U.S. and MRSA has become the most common cause ofskin and soft tissue infection in many parts of the world. There is now a much greater understanding of the physiology andevolution of the staphylococci and this new edition reflects therapid advancements in knowledge about this pathogen and provides acomprehensive review from both clinical and basic scienceperspectives. The first section addresses the basic biology of thestaphylococci, their molecular genetics, host defenses and hostevasion, virulence determinants, mechanisms of antibioticresistance, and laboratory techniques. The second section dealswith epidemiology, and the third section provides an overview ofthe varied clinical manifestations of human staphylococcalinfections. The fourth section covers prevention and treatment ofthese often life-threatening infections. Written by experts from around the globe, this book is essentialreading for all clinicians and basic scientists studying thestaphylococci.