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Journal of Molecular Biology Jul 2019The human oral cavity harbors diverse communities of microbes that live as biofilms: highly ordered, surface-associated assemblages of microbes embedded in an... (Review)
Review
The human oral cavity harbors diverse communities of microbes that live as biofilms: highly ordered, surface-associated assemblages of microbes embedded in an extracellular matrix. Oral microbial communities contribute to human health by fine-tuning immune responses and reducing dietary nitrate. Dental caries and periodontal disease are together the most prevalent microbially mediated human diseases worldwide. Both of these oral diseases are known to be caused not by the introduction of exogenous pathogens to the oral environment, but rather by a homeostasis breakdown that leads to changes in the structure of the microbial communities present in states of health. Both dental caries and periodontal disease are mediated by synergistic interactions within communities, and both diseases are further driven by specific host inputs: diet and behavior in the case of dental caries and immune system interactions in the case of periodontal disease. Changes in community structure (taxonomic identity and abundance) are well documented during the transition from health to disease. In this review, changes in biofilm physical structure during the transition from oral health to disease and the concomitant relationship between structure and community function will be emphasized.
Topics: Bacteria; Biofilms; Dental Caries; Dental Plaque; Diet; Homeostasis; Humans; Periodontal Diseases
PubMed: 31103772
DOI: 10.1016/j.jmb.2019.05.016 -
Nature Reviews. Microbiology Feb 2023The biofilm matrix can be considered to be a shared space for the encased microbial cells, comprising a wide variety of extracellular polymeric substances (EPS), such as... (Review)
Review
The biofilm matrix can be considered to be a shared space for the encased microbial cells, comprising a wide variety of extracellular polymeric substances (EPS), such as polysaccharides, proteins, amyloids, lipids and extracellular DNA (eDNA), as well as membrane vesicles and humic-like microbially derived refractory substances. EPS are dynamic in space and time and their components interact in complex ways, fulfilling various functions: to stabilize the matrix, acquire nutrients, retain and protect eDNA or exoenzymes, or offer sorption sites for ions and hydrophobic substances. The retention of exoenzymes effectively renders the biofilm matrix an external digestion system influencing the global turnover of biopolymers, considering the ubiquitous relevance of biofilms. Physico-chemical and biological interactions and environmental conditions enable biofilm systems to morph into films, microcolonies and macrocolonies, films, ridges, ripples, columns, pellicles, bubbles, mushrooms and suspended aggregates - in response to the very diverse conditions confronting a particular biofilm community. Assembly and dynamics of the matrix are mostly coordinated by secondary messengers, signalling molecules or small RNAs, in both medically relevant and environmental biofilms. Fully deciphering how bacteria provide structure to the matrix, and thus facilitate and benefit from extracellular reactions, remains the challenge for future biofilm research.
Topics: Extracellular Polymeric Substance Matrix; Biofilms; DNA; Polysaccharides; Proteins
PubMed: 36127518
DOI: 10.1038/s41579-022-00791-0 -
International Journal of Molecular... Jul 2022It is estimated that <0 [...]
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Topics: Anti-Bacterial Agents; Biofilms; Microbial Sensitivity Tests
PubMed: 35887278
DOI: 10.3390/ijms23147932 -
FEMS Microbiology Reviews May 2017Biofilms are surface-attached groups of microbial cells encased in an extracellular matrix that are significantly less susceptible to antimicrobial agents than... (Review)
Review
Biofilms are surface-attached groups of microbial cells encased in an extracellular matrix that are significantly less susceptible to antimicrobial agents than non-adherent, planktonic cells. Biofilm-based infections are, as a result, extremely difficult to cure. A wide range of molecular mechanisms contribute to the high degree of recalcitrance that is characteristic of biofilm communities. These mechanisms include, among others, interaction of antimicrobials with biofilm matrix components, reduced growth rates and the various actions of specific genetic determinants of antibiotic resistance and tolerance. Alone, each of these mechanisms only partially accounts for the increased antimicrobial recalcitrance observed in biofilms. Acting in concert, however, these defences help to ensure the survival of biofilm cells in the face of even the most aggressive antimicrobial treatment regimens. This review summarises both historical and recent scientific data in support of the known biofilm resistance and tolerance mechanisms. Additionally, suggestions for future work in the field are provided.
Topics: Anti-Bacterial Agents; Bacteria; Biofilms; Drug Resistance, Microbial; Extracellular Matrix; Microbial Sensitivity Tests; Plankton
PubMed: 28369412
DOI: 10.1093/femsre/fux010 -
Critical Reviews in Biotechnology Dec 2023The increased presence of xenobiotics affects living organisms and the environment at large on a global scale. Microbial degradation is effective for the removal of... (Review)
Review
The increased presence of xenobiotics affects living organisms and the environment at large on a global scale. Microbial degradation is effective for the removal of xenobiotics from the ecosystem. In natural habitats, biofilms are formed by single or multiple populations attached to biotic/abiotic surfaces and interfaces. The attachment of microbial cells to these surfaces is possible the matrix of extracellular polymeric substances (EPSs). However, the molecular machinery underlying the development of biofilms differs depending on the microbial species. Biofilms act as biocatalysts and degrade xenobiotic compounds, thereby removing them from the environment. Quorum sensing (QS) helps with biofilm formation and is linked to the development of biofilms in natural contaminated sites. To date, scant information is available about the biofilm-mediated degradation of toxic chemicals from the environment. Therefore, we review novel insights into the impact of microbial biofilms in xenobiotic contamination remediation, the regulation of biofilms in contaminated sites, and the implications for large-scale xenobiotic compound treatment.
Topics: Xenobiotics; Ecosystem; Biofilms; Quorum Sensing
PubMed: 36170978
DOI: 10.1080/07388551.2022.2106417 -
Monographs in Oral Science 2023Bacteria, fungi, archaea, protozoa, viruses, and bacteriophages colonize the oral cavity and, in combination, they form the oral microbiome. The coexistence of different... (Review)
Review
Bacteria, fungi, archaea, protozoa, viruses, and bacteriophages colonize the oral cavity and, in combination, they form the oral microbiome. The coexistence of different microorganisms and the microbial balance at each specific site are warranted by synergistic and antagonist interactions among members of the microbial communities. This microbiological balance suppresses the growth of potentially pathogenic microorganisms, generally keeping them at low abundance in the colonized sites. Microbial communities coexist in harmony with the host being compatible with a health condition. On the other hand, stressors exert selective pressure on the microbiota, promoting disruption in microbial homeostasis leading to dysbiosis. In this process, potentially pathogenic microorganisms become more abundant, resulting in microbial communities with altered properties and functions. Once the dysbiotic state has been reached, increased disease risk is expected. Biofilm is essential for caries development. The knowledge of the composition and metabolic interactions in the microbial community is fundamental for developing effective preventive and therapeutic measures. Studying both health and cariogenic conditions will bring an essential understanding of the disease process. Recent advances in omics approaches provide an unparalleled potential to reveal new insights about dental caries. This chapter will discuss a broader perspective on the etiology and pathogenesis of coronal dental caries from biofilm structure to microbial interactions.
Topics: Humans; Dental Caries; Mouth; Bacteria; Microbiota; Biofilms; Dysbiosis
PubMed: 37364551
DOI: 10.1159/000530558 -
ACS Infectious Diseases Feb 2018Microbial biofilms, which are elaborate and highly resistant microbial aggregates formed on surfaces or medical devices, cause two-thirds of infections and constitute a... (Review)
Review
Microbial biofilms, which are elaborate and highly resistant microbial aggregates formed on surfaces or medical devices, cause two-thirds of infections and constitute a serious threat to public health. Immunocompromised patients, individuals who require implanted devices, artificial limbs, organ transplants, or external life support and those with major injuries or burns, are particularly prone to become infected. Antibiotics, the mainstay treatments of bacterial infections, have often proven ineffective in the fight against microbes when growing as biofilms, and to date, no antibiotic has been developed for use against biofilm infections. Antibiotic resistance is rising, but biofilm-mediated multidrug resistance transcends this in being adaptive and broad spectrum and dependent on the biofilm growth state of organisms. Therefore, the treatment of biofilms requires drug developers to start thinking outside the constricted "antibiotics" box and to find alternative ways to target biofilm infections. Here, we highlight recent approaches for combating biofilms focusing on the eradication of preformed biofilms, including electrochemical methods, promising antibiofilm compounds and the recent progress in drug delivery strategies to enhance the bioavailability and potency of antibiofilm agents.
Topics: Anti-Infective Agents; Bacterial Infections; Biofilms; Drug Delivery Systems; Drug Resistance, Bacterial; Electrochemical Techniques; Humans
PubMed: 29280609
DOI: 10.1021/acsinfecdis.7b00170 -
Periodontology 2000 Jun 2021Recent advances in our understanding of the microbial populations that colonize the human mouth, their acquisition, interdependency, and coevolution with the host, bring... (Review)
Review
Recent advances in our understanding of the microbial populations that colonize the human mouth, their acquisition, interdependency, and coevolution with the host, bring a different perspective to the mechanisms underpinning the maintenance of periodontal health and the development of disease. In this work we suggest that our knowledge map of the etiology of periodontal health and disease can be viewed as a broad, highly connected, and integrated system that spans the entire spectrum of microbe/host/clinical interactions. The overall concept of present Periodontology 2000, that the microbial biofilm can be considered a human tissue of bacteriological origin, is entirely consistent with this integrated system view. The health-associated community structure of microbial biofilms can be considered a system that is normally resilient to perturbation. Equally, there is evidence to suggest that the dysbiotic community structure in disease may share similar resilience properties. In both instances, the resilience may be governed by the precise makeup of the acquired microbiome and by the genetics of the host. Understanding the mechanisms that enable the resistance to change of healthy and dysbiotic microbial populations may be important in the development of approaches to prevent the progression of disease and to restore health in diseased individuals.
Topics: Biofilms; Dysbiosis; Humans; Microbiota; Mouth
PubMed: 33690926
DOI: 10.1111/prd.12377 -
Microbial Ecology Jul 2018Microbial biofilms are multicellular communities of sessile microorganisms encased by the hydrated polymeric matrix. They have significant influences on both...
Microbial biofilms are multicellular communities of sessile microorganisms encased by the hydrated polymeric matrix. They have significant influences on both aquatic/terrestrial ecosystem and anthropogenic activities. Taking advantage of the governing features of selective stress (Tan and Ng in Water Res 42:1122-1132, 2008; Wei in Water Res 45:863-871, 2011; Dereli in Water Res 59C:11-22, 2014), the evenness of microbial communities in a membrane-centered mesocosm was successfully manipulated. By measuring the biofilm growing rates under different evenness levels of communities, an evenly distributed community favors the formation of biofilms was observed. This finding is not only a new evidence linking biofilm diversity to its functionality but also a clear suggestion on controlling a biofilm-based process via a simple and smart way.
Topics: Bacteria; Biofilms; Biofouling; Bioreactors; Ecology; Membranes, Artificial; Microbiota; Sewage; Waste Disposal, Fluid; Wastewater; Water Purification
PubMed: 29520452
DOI: 10.1007/s00248-018-1173-5 -
Medical Mycology Oct 2021Biofilms are important virulence factor in infections caused by microorganisms because of its complex structure, which provide resistance to conventional antimicrobials.... (Review)
Review
UNLABELLED
Biofilms are important virulence factor in infections caused by microorganisms because of its complex structure, which provide resistance to conventional antimicrobials. Strategies involving the use of molecules capable of inhibiting their formation and also act synergistically with conventional drugs have been explored. Farnesol is a molecule present in essential oils and produced by Candida albicans as a quorum sensing component. This sesquiterpene presents inhibitory properties in the formation of microbial biofilms and synergism with antimicrobials used in clinical practice, and can be exploited even for eradication of biofilms formed by drug-resistant microorganisms. Despite this, farnesol has physical and chemical characteristics that can limit its use, such as high hydrophobicity and volatility. Therefore, nanotechnology may represent an option to improve the efficiency of this molecule in high complex environments such as biofilms. Nanostructured systems present important results in the improvement of treatment with different commercial drugs and molecules with therapeutic or preventive potential. The formation of nanoparticles offers advantages such as protection of the incorporated drugs against degradation, improved biodistribution and residence time in specific treatment sites. The combination of farnesol with nanotechnology may be promising for the development of more effective antibiofilm therapies, as it can improve its solubility, reduce volatility, and increase bioavailability. This review summarizes existing data about farnesol, its action on biofilms, and discusses its encapsulation in nanostructured systems.
LAY SUMMARY
Farnesol is a natural compound that inhibits the formation of biofilms from different microbial species. The encapsulation of this molecule in nanoparticles is a promising alternative for the development of more effective therapies against biofilms.
Topics: Animals; Biofilms; Candida albicans; Farnesol; Nanotechnology; Tissue Distribution
PubMed: 33877362
DOI: 10.1093/mmy/myab020