The Role Of Biofilms In Device Related Infections

Approximately 60% of all hospital-associated infections, over one million cases per year, are due to biofilms that have formed on indwelling medical devices. Device-related biofilm infections increase hospital stays and add over one billion dollars/year to U.S. hospitalization costs. Since the use and the types of indwelling medical devices commonly used in modern healthcare are continuously expanding, especially with an aging population, the incidence of biofilm infections will also continue to rise. The central problem with microbial biofilm infections of foreign bodies is their propensity to resist clearance by the host immune system and all antimicrobial agents tested to date. In fact, compared to their free floating, planktonic counterparts, microbes within a biofilm are 50 – 500 times more resistant to antimicrobial agents. Therefore, achieving therapeutic and non-lethal dosing regimens within the human host is impossible. The end result is a conversion from an acute infection to one that is persistent, chronic, and recurrent, most often requiring device removal in order to eliminate the infection. This text will describe the major types of device-related infections, and will explain the host, pathogen, and the unique properties of their interactions in order to gain a better understanding of these recalcitrant infections.

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.

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.

Biofilms are ubiquitous and their presence in industry can lead to production losses. However, nowhere do biofilms impact human health and welfare as much as those that are found contaminating the healthcare environment, surgical instruments, equipment, and medical implantable devices. Approximately 70% of healthcare-associated infections are due to biofilm formation, resulting in increased patient morbidity and mortality. Biofilms formed on medical implants are recalcitrant to antibiotic treatment, which leaves implant removal as the principal treatment option. In this book, we investigate the role of biofilms in breast and dental implant disease and cancer. We include in vitro models for investigating treatment of chronic wounds and disinfectant action against Candida sp. Also included are papers on the most recent strategies for treating biofilm infection ranging from antibiotics incorporated into bone void fillers to antimicrobial peptides and quorum sensing.

Despite advances in materials and sterilisation, patients who receive biomaterials of medical device implants are still at risk of developing an infection around the implantation site. This book reviews the fundamentals of biomaterials and medical device related infections and methods and materials for the treatment and prevention of infection. The first part of the book provides readers with an introduction to the topic including analyses of biofilms, diagnosis and treatment of infection, pathology and topography. The second part of the book discusses a range of established and novel technologies and materials which have been designed to prevent infection. Provides analysis of biofilms and their relevance to implant associated infections. Assesses technologies for controlling biofilms. Considers advantages and disadvantages of in vivo infection studies.

Rather than existing in a planktonic or free-living form, evidence indicates that microbes show a preference for living in a sessile form within complex communities called biofilms. Biofilms appear to afford microbes a survival advantage by optimizing nutrition, offering protection against hostile elements, and providing a network for cell-to-cell signaling and genetic exchange. Biofilms, Infection, and Antimicrobial Therapy provides an in-depth exploration of biofilms, offering broad background information, as well a detailed look at the serious concerns to which biofilm-associated infections give rise. Prosthetic device infections, such as those involving artificial heart valves, intravascular catheters, or prosthetic joints, are prime examples of biofilm-associated infections. With the increasing use of such devices in the modern practice of medicine, the prevalence of these infections is expected to increase. Unfortunately, one of the most troubling characteristics of microbes found in biofilms is a profound resistance to antimicrobial agents. As biofilm-associated infections are particularly difficult to treat, they result in significant mortality, morbidity, and increased economic burden. Clearly, a better understanding of the pathogenesis of these infections and improved means for prevention and treatment are urgently needed! InBiofilms, Infection, and Antimicrobial Therapy, Drs Pace, Rupp, and Finch assemble the contributions of more than 50 of the world’s leading authorities on microbial biofilms who present recent findings on antibacterial tolerance and bacterial persistence associated with biofilms and discuses the implications of those findings with regard to human health. They explore the molecular mechanisms of bacterial adherence, biofilm formation, regulation of biofilm maintenance, and cell-to-cell communication and present the latest information on various treatment protocols that should aid physicians in the treatment of these refractory and often difficult-to-treat infections.

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.

Biofilm Eradication and Preventions presents the basics of biofilm formation on medical devices, diseases related to this formation, and approaches pharmaceutical researchers need to take to limit this problem. Split into three parts, the first deals with the development and characterization of biofilm on the surfaces of implanted or inserted medical devices. Questions as to why biofilms form over medical device surfaces and what triggers biofilm formation are addressed. In the second section, the author discusses biofilm-mediated chronic infections occurred in various organs (eyes, mouth, wounds) and pharmaceutical and drug delivery knowledge gained from research in these area. The third part explores pharmaceutical approaches like lipid-and polymer-based drug delivery carriers for eradicating biofilm on device-related infections. In addition, this section also explores the topic of novel small molecule (like iron and its complexes/metal chelators) and a quorum-sensing inhibitors to control medical biofilm formation.