Biofilms are widespread in nature and constitute an important strategy implemented by microorganisms to survive in sometimes harsh environmental conditions. They can be beneficial or have a negative ...impact particularly when formed in industrial settings or on medical devices. As such, research into the formation and elimination of biofilms is important for many disciplines. Several new methodologies have been recently developed for, or adapted to, biofilm studies that have contributed to deeper knowledge on biofilm physiology, structure and composition. In this review, traditional and cutting-edge methods to study biofilm biomass, viability, structure, composition and physiology are addressed. Moreover, as there is a lack of consensus among the diversity of techniques used to grow and study biofilms. This review intends to remedy this, by giving a critical perspective, highlighting the advantages and limitations of several methods. Accordingly, this review aims at helping scientists in finding the most appropriate and up-to-date methods to study their biofilms.
Bacterial biofilms are complex surface attached communities of bacteria held together by self-produced polymer matrixs mainly composed of polysaccharides, secreted proteins, and extracellular DNAs. ...Bacterial biofilm formation is a complex process and can be described in five main phases: (i) reversible attachment phase, where bacteria non-specifically attach to surfaces; (ii) irreversible attachment phase, which involves interaction between bacterial cells and a surface using bacterial adhesins such as fimbriae and lipopolysaccharide (LPS); (iii) production of extracellular polymeric substances (EPS) by the resident bacterial cells; (iv) biofilm maturation phase, in which bacterial cells synthesize and release signaling molecules to sense the presence of each other, conducing to the formation of microcolony and maturation of biofilms; and (v) dispersal/detachment phase, where the bacterial cells depart biofilms and comeback to independent planktonic lifestyle. Biofilm formation is detrimental in healthcare, drinking water distribution systems, food, and marine industries, etc. As a result, current studies have been focused toward control and prevention of biofilms. In an effort to get rid of harmful biofilms, various techniques and approaches have been employed that interfere with bacterial attachment, bacterial communication systems (quorum sensing, QS), and biofilm matrixs. Biofilms, however, also offer beneficial roles in a variety of fields including applications in plant protection, bioremediation, wastewater treatment, and corrosion inhibition amongst others. Development of beneficial biofilms can be promoted through manipulation of adhesion surfaces, QS and environmental conditions. This review describes the events involved in bacterial biofilm formation, lists the negative and positive aspects associated with bacterial biofilms, elaborates the main strategies currently used to regulate establishment of harmful bacterial biofilms as well as certain strategies employed to encourage formation of beneficial bacterial biofilms, and highlights the future perspectives of bacterial biofilms.
The negative consequences of biofilms are widely reported. A defining feature of biofilms is the extracellular matrix, a complex mixture of biomacromolecules, termed EPS, which contributes to reduced ...antimicrobial susceptibility. EPS targeting is a promising, but underexploited, approach to biofilm control allowing disruption of the matrix and thereby increasing the susceptibility to antimicrobials. Nanoparticles (NPs) can play a very important role as ’carriers’ of EPS matrix disruptors, and several approaches have recently been proposed. In this review, we discuss the application of nanoparticles as antibiofilm technologies with a special emphasis on the role of the EPS matrix in the physicochemical regulation of the nanoparticle–biofilm interaction. We highlight the use of nanoparticles as a platform for a new generation of antibiofilm approaches.
Self-adhering bacterial communities embedded in a matrix of hydrated macromolecules, known as biofilms, are prevalent and widespread. The matrix offers protection to the bacteria, reducing the cell susceptibility to antimicrobials.Functional nanoparticles are a promising technology to control or eradicate biofilms, providing the ability to enhance antimicrobial transport to the cell vicinity or alternatively to carry matrix dispersion agents.Critical to the development of novel strategies to control biofilm infections is an in-depth knowledge of the biofilm matrix which is still poorly understood due to its spatial and chemical variability and complexityA fundamental understanding of NP–EPS interactions has the potential to improve our ability to design more effective antibiofilm strategies.
Present day awareness of biofilm colonization on polymeric surfaces has prompted the scientific community to develop an ever-increasing number of new materials with anti-biofilm features. However, ...compared to the large amount of work put into discovering potent biofilm inhibitors, only a small number of papers deal with their validation, a critical step in the translation of research into practical applications. This is due to the lack of standardized testing methods and/or of well-controlled in vivo studies that show biofilm prevention on polymeric surfaces; furthermore, there has been little correlation with the reduced incidence of material deterioration. Here an overview of the most common methods for studying biofilms and for testing the anti-biofilm properties of new surfaces is provided.
The negative impact of biofilms in both the industry and the human health, demands the development of strategies for the in situ and early detection of biofilm formation. In this review we describe ...potentiometric, voltammetric and impedance-based sensors as to provide an overview of the different electrochemical techniques applied in biofilm detection and monitoring.
Display omitted
•Biofilms cause industrial activities impairment and human infections.•Early biofilm detection could prevent negative associated effect.•Traditional techniques are not suitable for biofilms monitoring.•Electrochemical sensor may represent a valid alternative to biofilm monitoring.
Biofilms are microbial communities established in the self‐produced extracellular substances that include up to 80% of associated microbial infections. During biofilm formation, bacterial cells shift ...from the planktonic forms to aggregated forms surrounded by an extracellular polymeric substance. The bacterial biofilm shows resistance against immune reactions as well as antibiotics and is potentially able to cause disorders by both device‐related and nondevice‐related infections. The nondevice‐related bacterial biofilm infections include dental plaque, urinary tract infections, cystic fibrosis, otitis media, infective endocarditis, tonsillitis, periodontitis, necrotizing fasciitis, osteomyelitis, infectious kidney stones, and chronic inflammatory diseases. In this review, we will summarize and examine the literature about bacterial biofilm infections unrelated to indwelling devices.
Fungal infections are an important and increasing global threat, carrying not only high morbidity and mortality rates, but also high healthcare costs. Without an effective response, it is predicted ...that 10 million people will die per year as a result of multi-drug-resistant pathogens. A high percentage of the mortalities caused by fungi are known to be biofilm-related.This Special Issue, “Fungal Biofilms 2020”, is intended to cover the state of fungal biofilm research, from virulence and pathogenicity, to new compounds with antibiofilm and antifungal activity. We welcome reviews and original research articles covering the development/evaluation/validation of recent studies, especially those regarding multidrug resistance.
Biofilms: Survival and defense strategy for pathogens Kumar, Ashutosh; Alam, Anwar; Rani, Mamta ...
International journal of medical microbiology,
December 2017, 2017-Dec, 2017-12-00, 20171201, Letnik:
307, Številka:
8
Journal Article
Recenzirano
Studies on biofilm related infections are gaining prominence owing to their involvement in majority of clinical infections. Biofilm, considered as a generic mechanism for survival used by pathogenic ...as well as non-pathogenic microorganisms, involves surface attachment and growth of heterogeneous cells encapsulated within a matrix. The matrix provides ecological niche where partnership of cells endows a community like behaviour that not only enables the cohort to survive local microenvironment stress but also channelizes them to evolve, disseminate and cause resurgence of infections. In this mini-review we highlight the mechanisms used by microbes to develop and sustain biofilms, including the influence of the microbiota. Several strategies to target biofilms have been validated on certain groups of microorganisms and these basically target different stages in the life cycle of biofilm, however comprehensive methods to target microbial biofilms are relatively unknown. In the backdrop of recent reports suggesting that biofilms can harbour multiple species of organisms, we need to relook and devise newer strategies against biofilms. Effective anti-biofilm strategies cannot be confined to a single methodology that can disrupt one pathway but should simultaneously target the various routes adopted by the microorganisms for survival within their ecosystem. An overview of the currently available drugs, their mode of action, genomic targets and translational therapies against biofilm related infection are discussed.
Among cell surface proteins, biofilm-associated protein (Bap) promotes biofilm development in Staphylococcus aureus strains. The aim of this study was to investigate proteinase-mediated biofilm ...dispersion in different isolates of S. aureus.
Biofilm assay was done in 96-well microtitre plate to evaluate the effect of proteinase K on biofilms of bovine mastitis S. Aureus isolates. Extracellular polymeric substances were extracted and evaluated for their composition (protein, polysaccharides and extracellular DNA), before and after the proteinase K treatment.
Biofilm assay showed that 2 μg/ml proteinase K significantly inhibited biofilm development in bap-positive S. aureus V329 as well as other S. aureus isolates (SA7, SA10, SA33, SA352), but not in bap-mutant M556 and SA392 (a weak biofilm-producing strain). Proteinase K treatment on S. aureus planktonic cells showed that there was no inhibition of planktonic growth up to 32 μg/ml of proteinase K. Proteinase K treatment on 24 h old preformed biofilms showed an enhanced dispersion of bap-positive V329 and SA7, SA10, SA33 and SA352 biofilms; however, proteinase K did not affect the bap-mutant S. aureus M556 and SA392 biofilms. Biofilm compositions study before and after proteinase K treatment indicated that Bap might also be involved in eDNA retention in the biofilm matrix that aids in biofilm stability. When proteinase K was used in combination with antibiotics, a synergistic effect in antibiotic efficacy was observed against all biofilm-forming S. aureus isolates.
Proteinase K inhibited biofilms growth in S. aureus bovine mastitis isolates but did not affect their planktonic growth. An enhanced dispersion of preformed S. aureus biofilms was observed on proteinase K treatment. Proteinase K treatment with antibiotics showed a synergistic effect against S. aureus biofilms. The study suggests that dispersing S. aureus by protease can be of use while devising strategies againstS. aureus biofilms.
PDF
