Role Of Microbial Biofilms Research Articles

Revealing microbial components in biofilm on aquatic insect cadavers: an experimental taphonomic study

The La Cantera Formation, recognized as a Konservat-Lagerstätten, preserves exceptional aquatic insect fossils from the Early Cretaceous. This study explores, using experimental taphonomy, the role of microbial biofilms in the preservational process over aquatic insects. An experimental analysis is proposed to understand the impact of microorganisms on decomposition and preservation. The investigation focuses on aquatic insects as model organisms because they are relevant in the La Cantera insect record. The experiment, conducted in controlled conditions, includes inhibitors targeting algae, bacteria, and fungi, revealing the development of biofilms and their impact on insect preservation. The differential development of microorganisms under each treatment indicates that biofilms, composed of algae and fungi, significantly impact the preservation of corpses by preventing disarticulation and facilitating preservation. This suggests that microbial mats could be crucial in forming exceptional paleontological deposits. By comparing these findings with the fossil record from La Cantera, researchers may gain insight into the potential significance of microbial mats in forming such deposits. This research highlights the importance of understanding the role of microorganisms in preserving fossils and contributes to our understanding of paleontological processes. Keywords: experimental taphonomy, Heteroptera, microbial activity, La Cantera Formation.

The role of microbial biofilms in the development of respiratory system complications in patients with COVID-19: A literature review

One of the complications of COVID-19 is the development of acute respiratory failure, which may require artificial ventilation using an endotracheal tube to correct hypoxaemia. However, the establishment of biofilms during intubation of patients can pose a risk of microbial growth that can cause severe complications. Therefore, the research on the microbial composition of biofilms that causes such diseases becomes an urgent issue. The purpose of the research was to analyse and summarise the data from current studies on the role of microbial biofilms and their impact on the development of respiratory system complications in patients with COVID-19. After reviewing the literature, it was determined that Staphylococcus epidermidis, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans accounted for the majority of biofilms isolated from endotracheal tubes in patients with COVID-19. The level of antimicrobial resistance among the isolated strains was almost 70%. The examination of samples from endotracheal tubes identified representatives of the lung microbiome, Prevotella spp. and some species of Streptococcus, Veillonella. However, in the research on the microbial composition of biofilms isolated from endotracheal tubes, pathogenic representatives dominated, such as Pseudomonas spp., Staphylococcus spp., Streptococcus spp., Stenotrophomonas spp., Enterobacterales, Haemophilus spp. and Actinomyces spp. Changes in the composition of the lung microbiome in patients with COVID-19 can lead to the development of severe complications accompanied by the establishment of biofilms. Microorganisms in biofilms can be a reservoir for secondary pulmonary infections, which affects the duration of mechanical ventilation and the admission of patients with COVID-19 to intensive care units. The development and implementation of effective measures for the prevention and treatment of biofilm-related infections is an important task for modern medical practice

Micro-fractionation shows microbial community changes in soil particles below 20 μm

IntroductionMicro-scale analysis of microbes in soil is essential to the overall understanding of microbial organization, interactions, and ecosystem functioning. Soil fractionation according to its aggregated structure has been used to access microbial habitats. While bacterial communities have been extensively described, little is known about the fungal communities at scales relevant to microbial interactions.MethodsWe applied a gentle soil fractionation method to preserve stable aggregated structures within the range of micro-aggregates and studied fungal and bacterial communities as well as nitrogen cycling potentials in the pristine Rothamsted Park Grass soil (bulk soil) as well as in its particle size fractions (PSFs; >250 μm, 250–63 μm, 63–20 μm, 20–2 μm, <2 μm, and supernatant).ResultsOverall bacterial and fungal community structures changed in PSFs below 20 μm. The relative abundance of Basidiomycota decreased with decreasing particle size over the entire measure range, while Ascomycota showed an increase and Mucoromycota became more prominent in particles below 20 μm. Bacterial diversity was found highest in the < 2 μm fraction, but only a few taxa were washed-off during the procedure and found in supernatant samples. These taxa have been associated with exopolysaccharide production and biofilm formation (e.g., Pseudomonas, Massilia, Mucilaginibacter, Edaphobaculum, Duganella, Janthinobacterium, and Variovorax). The potential for nitrogen reduction was found elevated in bigger aggregates.DiscussionThe observed changes below 20 μm particle are in line with scales where microbes operate and interact, highlighting the potential to focus on little researched sub-fractions of micro-aggregates. The applied method shows potential for use in studies focusing on the role of microbial biofilms in soil and might also be adapted to research various other soil microbial functions. Technical advances in combination with micro-sampling methods in soil promise valuable output in soil studies when particles below 20 μm are included.

Innovations in Therapeutic Improvement of the Cutaneous Microbiome in Children with Atopic Dermatitis

Biofilm is the dominant form of skin microbiota organization that provides adhesion and preservation of microorganisms in the skin micro-environment. It is necessary to ensure epidermal barrier function and local immunomodulation. Staphylococcus aureus becomes the major colonizer of skin lesions in case of atopic dermatitis exacerbation, and it also can form the biofilms. S. aureus growth and biofilm formation due to other microbial commensals on the skin of patients with atopic dermatitis leads to chronic output of pro-inflammatory cytokines and later to abnormalities in healthy skin microbiome. The role of microbial biofilm in human’s health makes the skin microbiota an attractive target for therapeutic intervention in various skin diseases.

The Role of Microbial Biofilm in Removing Ammonia in Floating Treatment Wetlands

Abstract Laboratory experiments were conducted under controlled conditions to quantify the potential of microbial transformation associated with floating matrix of floating treatment wetland (FTW) in ammonia removal and nitrification kinetics. The effect of different design parameters on ammonia removal from synthetic medium was investigated to optimize system performance. Effects of surface area of mat material, range of ammonia concentrations, and aeration on ammonia removal kinetics were studied using microcosm systems. A simple dynamics model of mineral nitrogen transformation was used as a framework for interpreting the experimental results. The results revealed that ammonia removal was enhanced in FTWs, and the magnitude of removal was controlled by the design factors examined. Removal by nitrification was directly proportional to mat surface area. The higher ammonia removal efficiency was caused by a larger surface area, which could support the growth of more microbes. Removal rate constants for treatments were 0.011, 0.015, 0.026, 0.035, and 0.033 day–1 for T1, T2, T3, T4, and T5, respectively. There was also a clear inhibitory effect of NH3 on second-stage nitrification manifested as low production of NO3–. Quantitative index of optimized knit/calibrated knit indicated high inhibition effects of NH3 at high concentration of total ammonia (60 mg N L–1). There was no major effect of oxygen saturation on NHx removal using aerated and nonaerated conditions. Better mechanistic understanding of the fundamental processes operating in FTWs should provide the basis for improving FTW design and efficacy.

Role of microbial biofilms in the maintenance of oral health and in the development of dental caries and periodontal diseases. Consensus report of group 1 of the Joint EFP/ORCA workshop on the boundaries between caries and periodontal disease

The scope of this working group was to review (1) ecological interactions at the dental biofilm in health and disease, (2) the role of microbial communities in the pathogenesis of periodontitis and caries, and (3) the innate host response in caries and periodontal diseases. A health-associated biofilm includes genera such as Neisseria, Streptococcus, Actinomyces, Veillonella and Granulicatella. Microorganisms associated with both caries and periodontal diseases are metabolically highly specialized and organized as multispecies microbial biofilms. Progression of these diseases involves multiple microbial interactions driven by different stressors. In caries, the exposure of dental biofilms to dietary sugars and their fermentation to organic acids results in increasing proportions of acidogenic and aciduric species. In gingivitis, plaque accumulation at the gingival margin leads to inflammation and increasing proportions of proteolytic and often obligately anaerobic species. The natural mucosal barriers and saliva are the main innate defence mechanisms against soft tissue bacterial invasion. Similarly, enamel and dentin are important hard tissue barriers to the caries process. Given that the present state of knowledge suggests that the aetiologies of caries and periodontal diseases are mutually independent, the elements of innate immunity that appear to contribute to resistance to both are somewhat coincidental.

Microbial biofilm in human health - an updated theoretical and practical insight

Abstract The term biofilm designates an aggregate of microorganisms belonging to one or more species which adhere to various surfaces but also to each another. These microbial communities are included and interconnected within an organic structure known as slime, composed of protein substances, polysaccharides, and DNA. The Center for Disease prevention and control considers infections with bacteria in biofilms among the 7 most important challenges which must be overcome in order to improve the safety of health services. The risk of microbial biofilm development exists for a long list of medical devices and equipment, as well as in certain diseases such as cystic fibrosis. An aggravating aspect is represented by the almost 1,000 times higher antimicrobial resistance of bacteria growing and multiplying within biofilms. Thus, in case of biofilm-infected medical devices, the resistance to antimicrobial treatments requires the removal of the device which essentially means the failure of the exploratory or therapeutic intervention in question. The role of microbial biofilms in medical pathology is a subject that raises interest for both researchers and clinicians in order to establish new methods for prevention and treatment of biofilms. This paper is intended as an overview in the management of microbial biofilms, presenting future insights, with technological progress in microscopy, molecular genetics, and genome analysis. Therefore the present paper will focus on describing the mechanisms involved in biofilm development, biofilm related infections, methods of detection and quantification of microbial communities and therapeutical approaches.

Biogeochemistry and Nutrient Limitation of Microbial Biofilms in Devils Hole, Nevada

Abstract Little is known about the role of microbial biofilms in nutrient cycling and ecosystem processes within desert springs. However, biofilms produce microscale physicochemical variation important to ecosystem function. We used microelectrodes to measure microscale physicochemical (temperature, pH, O2, and H2S) heterogeneity in biofilms at Devils Hole, Nevada. Additionally, we measured water column and pore water nutrient concentrations in 2 autotrophic (Spirogyra, cyanobacteria) and 1 heterotrophic (Beggiatoa) biofilm types. Spirogyra and cyanobacteria followed similar physicochemical trends; however, Spirogyra had more pronounced diurnal and seasonal variation. Oxygen concentrations within the biofilms varied with sample month, light availability, and biofilm type. We also assessed the nutrient limitation of desert spring microbial biofilms using a nutrient-diffusing substrata experiment. Autotrophic and heterotrophic biofilms responded differently to nutrient treatments. The differences between cy...

Erratum: Sponge larval settlement cues: the role of microbial biofilms in a warming ocean

Microbial biofilms play important roles in initiating settlement of marine invertebrate larvae. Given the importance of habitat selection by the motile larval phase, understanding settlement choices is critical if we are to successfully predict the population dynamics of sessile adults. Marine microbial biofilms show remarkable variability in community composition, often mediated by environmental conditions and biofilm age. To determine if biofilm communities were influenced by the time allowed to establish (age) and/or seawater temperature, we manipulated experimental surfaces to firstly determine biofilm community composition and secondly test larval settlement responses for the abundant coral reef sponge Rhopaloeides odorabile. Microbial profiling of biofilms revealed different communities according to both age and temperature. Biofilm community composition, as a result of both elevated seawater temperature and biofilm age, contributed to settlement for sponge larvae with markedly higher numbers of larvae settling to biofilms developed over longer periods (10 d) and at temperatures 2–6°C above ambient.

Sponge larval settlement cues: the role of microbial biofilms in a warming ocean

Microbial biofilms play important roles in initiating settlement of marine invertebrate larvae. Given the importance of habitat selection by the motile larval phase, understanding settlement choices is critical if we are to successfully predict the population dynamics of sessile adults. Marine microbial biofilms show remarkable variability in community composition, often mediated by environmental conditions and biofilm age. To determine if biofilm communities were influenced by the time allowed to establish (age) and/or seawater temperature, we manipulated experimental surfaces to firstly determine biofilm community composition and secondly test larval settlement responses for the abundant coral reef sponge Rhopaloeides odorabile. Microbial profiling of biofilms revealed different communities according to both age and temperature. Biofilm community composition, as a result of both elevated seawater temperature and biofilm age, contributed to settlement for sponge larvae with markedly higher numbers of larvae settling to biofilms developed over longer periods (10 d) and at temperatures 2–6°C above ambient.

The role of microbial biofilms in chronic and acute wounds

Biofilm-infected wounds are difficult to diagnose, do not respond to usual antimicrobial treatments and can be painful and chronic. The authors describe the signs and treatments for biofilms.

The role of microbial biofilm in ventilator-associated pneumonia

The role of microbial biofilm in ventilator-associated pneumonia

The nature and role of microbial biofilm in infections associated with prosthetic devices

AbstractAn understanding of the role of microbial biofilm in infections associated with prosthetic devices is essential for the implementation of successful treatment regimens.

The role of microbial biofilms in deterioration of space station candidate materials

The role of microbial biofilms in deterioration of space station candidate materials

The role of microbial biofilms in deterioration of space station candidate materials

Formation of microbial biofilms on surfaces of a wide range of materials being considered as candidates for use on the International Space Station was investigated. The materials included a fibre-reinforced polymeric composite, an adhesive sealant, a polyimide insulation foam, teflon cable insulation, titanium, and an aliphatic polyurethane coating. They were exposed to a natural mixed population of bacteria under controlled conditions of temperature and relative humidity (RH). Biofilms formed on the surfaces of the materials at a wide range of temperatures and RHs. The biofilm population was dominated by Pseudomonas aeruginosa, Ochrobactrum anthropi, Alcaligenes denitrificans, Xanthomonas maltophila, and Vibrio harveyi. The biocide, diiodomethyl- p-tolyl-sulfone, impregnated in the polyurethane coating, was ineffective against microbial colonization and growth. Degradation of the polyurethane coatings was monitored with electrochemical impedance spectroscopy (EIS). The impedance spectra indicated that microbial degradation of the coating occurred in several stages. The initial decreases in impedance were due to the transport of water and solutes into the polymeric matrices. Further decreases were a result of polymer degradation by microorganisms. Our data showed that these candidate materials for space application are susceptible to biofilm formation and subsequent degradation. Our study suggests that candidate materials for use in space missions need to be carefully evaluated for their susceptibility to microbial biofilm formation and biodegradation.