-
Photodiagnosis and Photodynamic Therapy Mar 2021Microorganisms thrive in well-organized biofilm ecosystems. Biofilm-associated cells typically show increased resistance to antibiotics and contribute significantly to... (Review)
Review
Microorganisms thrive in well-organized biofilm ecosystems. Biofilm-associated cells typically show increased resistance to antibiotics and contribute significantly to treatment failure. This has prompted investigations aimed at developing advanced and novel antimicrobial approaches that could effectively overcome the shortcomings associated with conventional antibiotic therapy. Studies are ongoing to develop effective curative strategies ranging from the use of peptides, small molecules, nanoparticles to bacteriophages, sonic waves, and light energy targeting various structural and physiological aspects of biofilms. In photodynamic therapy, a light source of a specific wavelength is used to irradiate non-toxic photosensitizers such as tetrapyrroles, synthetic dyes or, naturally occurring compounds to generate reactive oxygen species that can exert a lethal effect on the microbe especially by disrupting the biofilm. The photosensitizer preferentially binds to and accumulates in the microbial cells without causing any damage to the host tissue. Currently, photodynamic therapy is increasingly being used for the treatment of oral caries and dental plaque, chronic wound infections, infected diabetic foot ulcers, cystic fibrosis, chronic sinusitis, implant device-associated infections, etc. This approach is recognized as safe, as it is non-toxic and minimally invasive, making it a reliable, realistic, and promising therapeutic strategy for reducing the microbial burden and biofilm formation in chronic infections. In this review article, we discuss the current and future potential strategies of utilizing photodynamic therapy to extend our ability to impede and eliminate biofilms in various medical conditions.
Topics: Anti-Infective Agents; Biofilms; Ecosystem; Photochemotherapy; Photosensitizing Agents
PubMed: 33157331
DOI: 10.1016/j.pdpdt.2020.102090 -
Journal of Materials Chemistry. B Jul 2022Biofilms are formed at interfaces by microorganisms, which congregate in microstructured communities embedded in a self-produced extracellular polymeric substance (EPS).... (Review)
Review
Biofilms are formed at interfaces by microorganisms, which congregate in microstructured communities embedded in a self-produced extracellular polymeric substance (EPS). Biofilm-related infections are problematic due to the high resistance towards most clinically used antimicrobials, which is associated with high mortality and morbidity, combined with increased hospital stays and overall treatment costs. Several new nanotechnology-based approaches have recently been proposed for targeting resistant bacteria and microbial biofilms. Here we discuss the impacts of biofilms on healthcare, food processing and packaging, and water filtration and distribution systems, and summarize the emerging nanotechnological strategies that are being developed for biofilm prevention, control and eradication. Combination of novel nanomaterials with conventional antimicrobial therapies has shown great potential in producing more effective platforms for controlling biofilms. Recent developments include antimicrobial nanocarriers with enzyme surface functionality that allow passive infection site targeting, degradation of the EPS and delivery of high concentrations of antimicrobials to the residing cells. Several stimuli-responsive antimicrobial formulation strategies have taken advantage of the biofilm microenvironment to enhance interaction and passive delivery into the biofilm sites. Nanoparticles of ultralow size have also been recently employed in formulations to improve the EPS penetration, enhance the carrier efficiency, and improve the cell wall permeability to antimicrobials. We also discuss antimicrobial metal and metal oxide nanoparticle formulations which provide additional mechanical factors through externally induced actuation and generate reactive oxygen species (ROS) within the biofilms. The review helps to bridge microbiology with materials science and nanotechnology, enabling a more comprehensive interdisciplinary approach towards the development of novel antimicrobial treatments and biofilm control strategies.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Biofilms; Extracellular Polymeric Substance Matrix; Nanotechnology
PubMed: 35735175
DOI: 10.1039/d2tb00233g -
ACS Sensors Feb 2022Microbial biofilms have caused serious concerns in healthcare, medical, and food industries because of their intrinsic resistance against conventional antibiotics and... (Review)
Review
Microbial biofilms have caused serious concerns in healthcare, medical, and food industries because of their intrinsic resistance against conventional antibiotics and cleaning procedures and their capability to firmly adhere on surfaces for persistent contamination. These global issues strongly motivate researchers to develop novel methodologies to investigate the kinetics underlying biofilm formation, to understand the response of the biofilm with different chemical and physical treatments, and to identify biofilm-specific drugs with high-throughput screenings. Meanwhile microbial biofilms can also be utilized positively as sensing elements in cell-based sensors due to their strong adhesion on surfaces. In this perspective, we provide an overview on the connections between sensing and microbial biofilms, focusing on tools used to investigate biofilm properties, kinetics, and their response to chemicals or physical agents, and biofilm-based sensors, a type of biosensor using the bacterial biofilm as a biorecognition element to capture the presence of the target of interest by measuring the metabolic activity of the immobilized microbial cells. Finally we discuss possible new research directions for the development of robust and rapid biofilm related sensors with high temporal and spatial resolutions, pertinent to a wide range of applications.
Topics: Anti-Bacterial Agents; Bacteria; Biofilms; Biosensing Techniques
PubMed: 35171575
DOI: 10.1021/acssensors.1c02722 -
Annals of the American Thoracic Society Sep 2016Microbial biofilms can colonize medical devices and human tissues, and their role in microbial pathogenesis is now well established. Not only are biofilms ubiquitous in... (Review)
Review
Microbial biofilms can colonize medical devices and human tissues, and their role in microbial pathogenesis is now well established. Not only are biofilms ubiquitous in natural and human-made environments, but they are also estimated to be associated with approximately two-thirds of nosocomial infections. This multicellular aggregated form of microbial growth confers a remarkable resistance to killing by antimicrobials and host defenses, leading biofilms to cause a wide range of subacute or chronic infections that are difficult to eradicate. We have gained tremendous knowledge on the molecular, genetic, microbiological, and biophysical processes involved in biofilm formation. These insights now shape our understanding, diagnosis, and management of many infectious diseases and direct the development of novel antimicrobial therapies that target biofilms. Bacterial and fungal biofilms play an important role in a range of diseases in pulmonary and critical care medicine, most importantly catheter-associated infections, ventilator-associated pneumonia, chronic Pseudomonas aeruginosa infections in cystic fibrosis lung disease, and Aspergillus fumigatus pulmonary infections.
Topics: Anti-Bacterial Agents; Bacteria; Biofilms; Catheter-Related Infections; Critical Illness; Cross Infection; Cystic Fibrosis; Humans; Microbial Sensitivity Tests; Pneumonia, Ventilator-Associated
PubMed: 27348071
DOI: 10.1513/AnnalsATS.201603-194FR -
Microbiology Spectrum Dec 2015One common feature of biofilm development is the active dispersal of cells from the mature biofilm, which completes the biofilm life cycle and allows for the subsequent... (Review)
Review
One common feature of biofilm development is the active dispersal of cells from the mature biofilm, which completes the biofilm life cycle and allows for the subsequent colonization of new habitats. Dispersal is likely to be critical for species survival and appears to be a precisely regulated process that involves a complex network of genes and signal transduction systems. Sophisticated molecular mechanisms control the transition of sessile biofilm cells into dispersal cells and their coordinated detachment and release in the bulk liquid. Dispersal cells appear to be specialized and exhibit a unique phenotype different from biofilm or planktonic bacteria. Further, the dispersal population is characterized by a high level of heterogeneity, reminiscent of, but distinct from, that in the biofilm, which could potentially allow for improved colonization under various environmental conditions. Here we review recent advances in characterizing the molecular mechanisms that regulate biofilm dispersal events and the impact of dispersal in a broader ecological context. Several strategies that exploit the mechanisms controlling biofilm dispersal to develop as applications for biofilm control are also presented.
Topics: Bacteria; Bacterial Physiological Phenomena; Biofilms; Ecosystem
PubMed: 27337281
DOI: 10.1128/microbiolspec.MB-0015-2014 -
The Science of the Total Environment Jun 2022Microbial biofilms are formed by adherence of the bacteria through their secreted polymer matrices. The major constituents of the polymer matrices are extracellular... (Review)
Review
Microbial biofilms are formed by adherence of the bacteria through their secreted polymer matrices. The major constituents of the polymer matrices are extracellular DNAs, proteins, polysaccharides. Biofilms have exhibited a promising role in the area of bioremediation. These activities can be further improved by tuning the parameters like quorum sensing, characteristics of the adhesion surface, and other environmental factors. Organic pollutants have created a global concern because of their long-term toxicity on human, marine, and animal life. These contaminants are not easily degradable and continue to prevail in the environment for an extended period. Biofilms are being used for the remediation of different pollutants, among which organic pollutants have been of significance. The bioremediation of organic contaminants using biofilms is an eco-friendly, cheap, and green process. However, the development of this technology demands knowledge on the mechanism of action of the microbes to form the biofilm, types of specific bacteria or fungi responsible for the degradation of a particular organic compound, and the mechanistic role of the biofilm in the degradation of the pollutants. This review puts forth a comprehensive summary of the role of microbial biofilms in the bioremediation of different environment-threatening organic pollutants.
Topics: Biodegradation, Environmental; Biofilms; Environmental Pollutants; Polymers; Quorum Sensing
PubMed: 35176385
DOI: 10.1016/j.scitotenv.2022.153843 -
Frontiers in Cellular and Infection... 2022
Topics: Biofilms; Candida albicans; Mucous Membrane
PubMed: 36275036
DOI: 10.3389/fcimb.2022.1049347 -
Advances in Experimental Medicine and... 2017Biofilm communities are an ingenious form of protection of microbial cells which have been evolving for billion of years. In general, ultraviolet (UV) radiation presents... (Review)
Review
Biofilm communities are an ingenious form of protection of microbial cells which have been evolving for billion of years. In general, ultraviolet (UV) radiation presents poor penetration in the matrix of biofilms and only the first few top layers of microbial cells are exposed to its deleterious effects. For further protection against UV radiation, exposed cells can produce specialized compounds such as mycosporine-like amino acids and carotenoid pigments. In this chapter, the adaptation mechanisms presented by biofilms against UV radiation are presented, as well as the application of UV light to monitor and destroy biofilms in man made surfaces.
Topics: Bacteria; Biofilms; Decontamination; Equipment Contamination; Microbial Viability; Sterilization; Ultraviolet Rays
PubMed: 29124704
DOI: 10.1007/978-3-319-56017-5_19 -
Journal of Basic Microbiology Jul 2017Microbial biofilms are a fascinating subject, due to their significant roles in the environment, industry, and health. Advances in biochemical and molecular techniques... (Review)
Review
Microbial biofilms are a fascinating subject, due to their significant roles in the environment, industry, and health. Advances in biochemical and molecular techniques have helped in enhancing our understanding of biofilm structure and development. In the past, research on biofilms primarily focussed on health and industrial sectors; however, lately, biofilms in agriculture are gaining attention due to their immense potential in crop production, protection, and improvement. Biofilms play an important role in colonization of surfaces - soil, roots, or shoots of plants and enable proliferation in the desired niche, besides enhancing soil fertility. Although reports are available on microbial biofilms in general; scanty information is published on biofilm formation by agriculturally important microorganisms (bacteria, fungi, bacterial-fungal) and their interactions in the ecosystem. Better understanding of agriculturally important bacterial-fungal communities and their interactions can have several implications on climate change, soil quality, plant nutrition, plant protection, bioremediation, etc. Understanding the factors and genes involved in biofilm formation will help to develop more effective strategies for sustainable and environment-friendly agriculture. The present review brings together fundamental aspects of biofilms, in relation to their formation, regulatory mechanisms, genes involved, and their application in different fields, with special emphasis on agriculturally important microbial biofilms.
Topics: Agriculture; Agrobacterium; Anabaena; Bacillus; Bacteria; Bacterial Adhesion; Bacterial Physiological Phenomena; Biofilms; Climate Change; Ecosystem; Fungi; Microbial Interactions; Plant Roots; Plants; Quorum Sensing; Soil Microbiology
PubMed: 28407275
DOI: 10.1002/jobm.201700046 -
Frontiers in Cellular and Infection... 2020Biofilms are communities of microorganisms that are attached to a biological or abiotic surface and are surrounded by a self-produced extracellular matrix. Cells within... (Review)
Review
Biofilms are communities of microorganisms that are attached to a biological or abiotic surface and are surrounded by a self-produced extracellular matrix. Cells within a biofilm have intrinsic characteristics that are different from those of planktonic cells. Biofilm resistance to antimicrobial agents has drawn increasing attention. It is well-known that medical device- and tissue-associated biofilms may be the leading cause for the failure of antibiotic treatments and can cause many chronic infections. The eradication of biofilms is very challenging. Many researchers are working to address biofilm-related infections, and some novel strategies have been developed and identified as being effective and promising. Nevertheless, more preclinical studies and well-designed multicenter clinical trials are critically needed to evaluate the prospects of these strategies. Here, we review information about the mechanisms underlying the drug resistance of biofilms and discuss recent progress in alternative therapies and promising strategies against microbial biofilms. We also summarize the strengths and weaknesses of these strategies in detail.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Biofilms; Extracellular Matrix; Multicenter Studies as Topic
PubMed: 32850471
DOI: 10.3389/fcimb.2020.00359