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Virulence Dec 2024Bacterial biofilms have attracted significant attention due to their involvement in persistent infections, food and water contamination, and infrastructure corrosion.... (Review)
Review
Bacterial biofilms have attracted significant attention due to their involvement in persistent infections, food and water contamination, and infrastructure corrosion. This review delves into the intricate interactions between bacterial biofilms and unicellular parasites, shedding light on their impact on biofilm formation, structure, and function. Unicellular parasites, including protozoa, influence bacterial biofilms through grazing activities, leading to adaptive changes in bacterial communities. Moreover, parasites like and can shape biofilm composition in a grazing independent manner, potentially influencing disease outcomes. Biofilms, acting as reservoirs, enable the survival of protozoan parasites against environmental stressors and antimicrobial agents. Furthermore, these biofilms may influence parasite virulence and stress responses, posing challenges in disease treatment. Interactions between unicellular parasites and fungal-containing biofilms is also discussed, hinting at complex microbial relationships in various ecosystems. Understanding these interactions offers insights into disease mechanisms and antibiotic resistance dissemination, paving the way for innovative therapeutic strategies and ecosystem-level implications.
Topics: Animals; Parasites; Ecosystem; Biofilms; Drug Resistance, Microbial; Anti-Infective Agents; Bacteria
PubMed: 38058008
DOI: 10.1080/21505594.2023.2289775 -
NPJ Biofilms and Microbiomes Sep 2023Bacterial biofilms, which consist of three-dimensional extracellular polymeric substance (EPS), not only function as signaling networks, provide nutritional support, and... (Review)
Review
Bacterial biofilms, which consist of three-dimensional extracellular polymeric substance (EPS), not only function as signaling networks, provide nutritional support, and facilitate surface adhesion, but also serve as a protective shield for the residing bacterial inhabitants against external stress, such as antibiotics, antimicrobials, and host immune responses. Biofilm-associated infections account for 65-80% of all human microbial infections that lead to serious mortality and morbidity. Tremendous effort has been spent to address the problem by developing biofilm-dispersing agents to discharge colonized microbial cells to a more vulnerable planktonic state. Here, we discuss the recent progress of enzymatic eradicating strategies against medical biofilms, with a focus on dispersal mechanisms. Particularly, we review three enzyme classes that have been extensively investigated, namely glycoside hydrolases, proteases, and deoxyribonucleases.
Topics: Humans; Extracellular Polymeric Substance Matrix; Biofilms; Anti-Bacterial Agents; Plankton; Signal Transduction
PubMed: 37679355
DOI: 10.1038/s41522-023-00427-y -
European Journal of Clinical... Aug 2023Bacteriophages (phages) are very promising biological agents for the prevention and control of bacterial biofilms. However, little is known about the parameters that can... (Review)
Review
Bacteriophages (phages) are very promising biological agents for the prevention and control of bacterial biofilms. However, little is known about the parameters that can influence the efficacy of phages on biofilms. This systematic review provides a summary and analysis of the published data about the use of phages to control pre-formed biofilms in vitro, suggesting recommendations for future experiments in this area. A total of 68 articles, containing data on 605 experiments addressing the efficacy of phages to control biofilms in vitro were included, after a search conducted in Web of Science, Embase, and Medline (PubMed). The data collected from each experiment included information about biofilm growth conditions, phage characteristics, treatment conditions and biofilm reduction. In most cases, biofilms were formed in the surface of microtiter plates (82.5%); the median time for biofilm formation was 24 h, as is the median treatment duration. Quantification of biofilm biomass (52.6%), viable cells (25.5%) and metabolic activity (17.9%) were the most common biofilm assessment methods. Correlation analysis revealed that some phage parameters can influence the treatment outcome: higher phage concentrations were strongly associated with improved biofilm control, leading to higher levels of biofilm reduction, and phages with higher burst sizes and shorter latent periods seem to be the best candidates to control biofilms in vitro. However, the great variability of the methodologies used prompts the need for the development of standardized in vitro methodologies to characterize phage/biofilm interactions and to assess the efficacy of phages to control biofilms.
Topics: Humans; Bacteriophages; Biofilms
PubMed: 37407800
DOI: 10.1007/s10096-023-04638-1 -
Trends in Biotechnology Apr 2024The eradication of drug-resistant microbial biofilms remains an unresolved global health challenge. Small-scale robotics are providing innovative therapeutic and... (Review)
Review
The eradication of drug-resistant microbial biofilms remains an unresolved global health challenge. Small-scale robotics are providing innovative therapeutic and diagnostic approaches with high precision and efficacy. These approaches are rapidly moving from proof-of-concept studies to translational biomedical applications using ex vivo, animal, and clinical models. Here, we discuss the fundamental and translational aspects of how microrobots target the infection sites to disrupt the structural and functional traits of biofilms and their antimicrobial resistance mechanisms. We emphasize current approaches of mechanochemical disruption and on-site drug delivery that are supported by in vivo models and preclinical testing, while also highlighting diagnostics potential. We also discuss clinical translation challenges and provide perspectives for development of microrobotics approaches to combat biofilm infections and biofouling in humans.
Topics: Animals; Humans; Biofilms; Drug Delivery Systems; Biofouling; Anti-Bacterial Agents
PubMed: 37968157
DOI: 10.1016/j.tibtech.2023.10.004 -
World Journal of Microbiology &... May 2024Plastic pollution in the form of microplastics (MPs), poses a significant threat to natural ecosystems, with detrimental ecological, social, and economic impacts. This... (Review)
Review
Plastic pollution in the form of microplastics (MPs), poses a significant threat to natural ecosystems, with detrimental ecological, social, and economic impacts. This review paper aims to provide an overview of the existing research on the interaction between microbial biofilms and MPs in natural environments. The review begins by outlining the sources and types of MPs, emphasizing their widespread presence in marine, freshwater, and terrestrial ecosystems. It then discusses the formation and characteristics of microbial biofilms on MPs surfaces, highlighting their role in altering the physicochemical properties of MPs and facilitating processes such as vertical transport, biodegradation, dispersion of microorganisms, and gene transfer. Different methods used to assess these interactions are discussed, including microbiological and physicochemical characterization. Current gaps and challenges in understanding the complex relationships between biofilms and MPs are identified, highlighting the need for further research to elucidate the mechanisms underlying these complex interactions and to develop effective mitigation strategies. Innovative solutions, including bioremediation techniques and their combination with other strategies, such as nanotechnology, advanced filtration technologies, and public awareness campaigns, are proposed as promising approaches to address the issue of MPs pollution. Overall, this review underscores the urgent need for a multidisciplinary approach to combating MPs pollution, combining scientific research, technological innovation, and public engagement to safeguard the health and integrity of natural ecosystems.
Topics: Microplastics; Biofilms; Biodegradation, Environmental; Ecosystem; Bacteria; Plastics; Environmental Pollution; Water Pollutants, Chemical; Fresh Water
PubMed: 38809290
DOI: 10.1007/s11274-024-04021-y -
Microbial Biotechnology Sep 2023Microbial attachment and biofilm formation is a ubiquitous behaviour of microorganisms and is the most crucial prerequisite of contact bioleaching. Monazite and xenotime...
Microbial attachment and biofilm formation is a ubiquitous behaviour of microorganisms and is the most crucial prerequisite of contact bioleaching. Monazite and xenotime are two commercially exploitable minerals containing rare earth elements (REEs). Bioleaching using phosphate solubilizing microorganisms is a green biotechnological approach for the extraction of REEs. In this study, microbial attachment and biofilm formation of Klebsiella aerogenes ATCC 13048 on the surface of these minerals were investigated using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). In a batch culture system, K. aerogenes was able to attach and form biofilms on the surface of three phosphate minerals. The microscopy records showed three distinctive stages of biofilm development for K. aerogenes commencing with initial attachment to the surface occurring in the first minutes of microbial inoculation. This was followed by colonization of the surface and formation of a mature biofilm as the second distinguishable stage, with progression to dispersion as the final stage. The biofilm had a thin-layer structure. The colonization and biofilm formation were localized toward physical surface imperfections such as cracks, pits, grooves and dents. In comparison to monazite and xenotime crystals, a higher proportion of the surface of the high-grade monazite ore was covered by biofilm which could be due to its higher surface roughness. No selective attachment or colonization toward specific mineralogy or chemical composition of the minerals was detected. Finally, in contrast to abiotic leaching of control samples, microbial activity resulted in extensive microbial erosion on the high-grade monazite ore.
Topics: Biofilms; Minerals; Microscopy, Confocal; Microscopy, Electron, Scanning; Phosphates
PubMed: 37291762
DOI: 10.1111/1751-7915.14260 -
Journal of Bacteriology Oct 2023is one of the most common biofilm-forming pathogens responsible for lung infections of individuals with cystic fibrosis (CF). becomes tolerant to antimicrobials in the...
is one of the most common biofilm-forming pathogens responsible for lung infections of individuals with cystic fibrosis (CF). becomes tolerant to antimicrobials in the biofilm state and is difficult to treat. Production of extracellular polymeric substances (EPS), such as alginate and extracellular DNA (eDNA), can allow adherence to abiotic and biotic surfaces, antimicrobial evasion, and resilience to environmental pressures. Alginate-producing mucoid variants of are frequently isolated from CF airway samples and are associated with worsening patient outcomes. While eDNA is a major structural component of nonmucoid biofilms, the potential role of eDNA in mucoid biofilms is unclear. Here, we investigate how eDNA contributes to clinical mucoid biofilm physiology and integrity. We predicted that eDNA plays a structural and mechanical role in mucoid biofilms. To test this, we quantified biofilm eDNA in mucoid biofilms and used microscopy and rheology to visualize eDNA and detect changes in biofilm structure and mechanics upon DNaseI treatment. We showed that biofilm eDNA abundance is diverse across clinical mucoid strains and observed a temporal increase in foci of eDNA within intact mucoid biofilms. Increased cell dispersal and reduced biomass were also observed following DNaseI treatment of mucoid biofilms. Degradation of eDNA also impacted the mechanical integrity of mucoid biofilms by increasing the stiffness and decreasing the cohesion of the biofilm. These findings advance our understanding of clinical mucoid biofilms and facilitate the development of new approaches to target biofilms by exploiting the functions of EPS components. IMPORTANCE Understanding the role of eDNA in mucoid biofilms will lead to therapeutic strategies that combat the biophysical and structural function of EPS for the eradication of bacteria in mucoid biofilms during chronic infections. This knowledge can be used to further identify unknown matrix component interactions within pathogenic biofilm-forming clinical isolates.
Topics: Humans; Pseudomonas aeruginosa; Polysaccharides, Bacterial; Biofilms; Anti-Infective Agents; Alginates; DNA; Pseudomonas Infections
PubMed: 37791754
DOI: 10.1128/jb.00238-23 -
FEMS Microbiology Ecology Oct 2023This study employs a bibliography study method to evaluate 472 papers focused on Shewanella oneidensis biofilms. Biofilms, which are formed when microorganisms adhere to...
This study employs a bibliography study method to evaluate 472 papers focused on Shewanella oneidensis biofilms. Biofilms, which are formed when microorganisms adhere to surfaces or interfaces, play a crucial role in various natural, engineered, and medical settings. Within biofilms, microorganisms are enclosed in extracellular polymeric substances (EPS), creating a stable working environment. This characteristic enhances the practicality of biofilm-based systems in natural bioreactors, as they are less susceptible to temperature and pH fluctuations compared to enzyme-based bioprocesses. Shewanella oneidensis, a nonpathogenic bacterium with the ability to transfer electrons, serves as an example of a species isolated from its environment that exhibits extensive biofilm applications. These applications, such as heavy metal removal, offer potential benefits for environmental engineering and human health. This paper presents a comprehensive examination and review of the biology and engineering aspects of Shewanella biofilms, providing valuable insights into their functionality.
Topics: Humans; Biofilms; Shewanella; Electrons; Bioreactors
PubMed: 37796898
DOI: 10.1093/femsec/fiad124 -
Bioorganic Chemistry Jun 2024Building upon our previous study on peptoid-based antibacterials which showed good activity against Gram-positive bacteria only, herein we report the synthesis of 34...
Building upon our previous study on peptoid-based antibacterials which showed good activity against Gram-positive bacteria only, herein we report the synthesis of 34 dimeric peptoid compounds and the investigation of their activity against Gram-positive and Gram-negative pathogens. The newly designed peptoids feature a di-hydrophobic moiety incorporating phenyl, bromo-phenyl, and naphthyl groups, combined with variable lengths of cationic units such as amino and guanidine groups. The study also underscores the pivotal interplay between hydrophobicity and cationicity in optimizing efficacy against specific bacteria. The bromophenyl dimeric guanidinium peptoid compound 10j showed excellent activity against S. aureus 38 and E. coli K12 with MIC of 0.8 μg mL and 6.2 μg mL, respectively. Further investigation into the mechanism of action revealed that the antibacterial effect might be attributed to the disruption of bacterial cell membranes, as suggested by tethered bilayer lipid membranes (tBLMs) and cytoplasmic membrane permeability studies. Notably, these promising antibacterial agents exhibited negligible toxicity against mammalian red blood cells. Additionally, the study explored the potential of 12 active compounds to disrupt established biofilms of S. aureus 38. The most effective biofilm disruptors were ethyl and octyl-naphthyl guanidinium peptoids (10c and 10 k). These compounds 10c and 10 k disrupted the established biofilms of S. aureus 38 with 51 % at 4x MIC (MIC = 17.6 μg mL and 11.2 μg mL) and 56 %-58 % at 8x MIC (MIC = 35.2 μg mL and 22.4 μg mL) respectively. Overall, this research contributes insights into the design principles of cationic dimeric peptoids and their antibacterial activity, with implications for the development of new antibacterial compounds.
Topics: Anti-Bacterial Agents; Peptoids; Microbial Sensitivity Tests; Biofilms; Staphylococcus aureus; Structure-Activity Relationship; Molecular Structure; Dose-Response Relationship, Drug; Dimerization; Escherichia coli; Humans; Erythrocytes
PubMed: 38583251
DOI: 10.1016/j.bioorg.2024.107334 -
FEMS Microbiology Reviews Sep 2023In vitro biofilms are communities of microbes with unique features compared to individual cells. Biofilms are commonly characterized by physical traits like size,...
In vitro biofilms are communities of microbes with unique features compared to individual cells. Biofilms are commonly characterized by physical traits like size, adhesion, and a matrix made of extracellular substances. They display distinct phenotypic features, such as metabolic activity and antibiotic tolerance. However, the relative importance of these traits depends on the environment and bacterial species. Various mechanisms enable biofilm-associated bacteria to withstand antibiotics, including physical barriers, physiological adaptations, and changes in gene expression. Gene expression profiles in biofilms differ from individual cells but, there is little consensus among studies and so far, a 'biofilm signature transcriptome' has not been recognized. Additionally, the spatial and temporal variability within biofilms varies greatly depending on the system or environment. Despite all these variable conditions, which produce very diverse structures, they are all noted as biofilms. We discuss that clinical biofilms may differ from those grown in laboratories and found in the environment and discuss whether the characteristics that are commonly used to define and characterize biofilms have been shown in infectious biofilms. We emphasize that there is a need for a comprehensive understanding of the specific traits that are used to define bacteria in infections as clinical biofilms.
Topics: Adaptation, Physiological; Anti-Bacterial Agents; Biofilms; Phenotype; Drug Resistance, Bacterial
PubMed: 37656883
DOI: 10.1093/femsre/fuad050