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Computational and Experimental Investigation of Biofilm Disruption Dynamics Induced by High-Velocity Gas Jet Impingement. mBio 2020; 11:mBio.02813-19. [PMID: 31911489 PMCID: PMC6946800 DOI: 10.1128/mbio.02813-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Knowledge of mechanisms promoting disruption though mechanical forces is essential in optimizing biofilm control strategies which rely on fluid shear. Our results provide insight into how biofilm disruption dynamics is governed by applied forces and fluid properties, revealing a mechanism for ripple formation and fluid-biofilm mixing. These findings have important implications for the rational design of new biofilm cleaning strategies with fluid jets, such as determining optimal parameters (e.g., jet velocity and position) to remove the biofilm from a certain zone (e.g., in dental hygiene or debridement of surgical site infections) or using antimicrobial agents which could increase the interfacial area available for exchange, as well as causing internal mixing within the biofilm matrix, thus disrupting the localized microenvironment which is associated with antimicrobial tolerance. The developed model also has potential application in predicting drag and pressure drop caused by biofilms on bioreactor, pipeline, and ship hull surfaces. Experimental data showed that high-speed microsprays can effectively disrupt biofilms on their support substratum, producing a variety of dynamic reactions such as elongation, displacement, ripple formation, and fluidization. However, the mechanics underlying the impact of high-speed turbulent flows on biofilm structure is complex under such extreme conditions, since direct measurements of viscosity at these high shear rates are not possible using dynamic testing instruments. Here, we used computational fluid dynamics simulations to assess the complex fluid interactions of ripple patterning produced by high-speed turbulent air jets impacting perpendicular to the surface of Streptococcus mutans biofilms, a dental pathogen causing caries, captured by high-speed imaging. The numerical model involved a two-phase flow of air over a non-Newtonian biofilm, whose viscosity as a function of shear rate was estimated using the Herschel-Bulkley model. The simulation suggested that inertial, shear, and interfacial tension forces governed biofilm disruption by the air jet. Additionally, the high shear rates generated by the jet impacts coupled with shear-thinning biofilm property resulted in rapid liquefaction (within milliseconds) of the biofilm, followed by surface instability and traveling waves from the impact site. Our findings suggest that rapid shear thinning under very high shear flows causes the biofilm to behave like a fluid and elasticity can be neglected. A parametric sensitivity study confirmed that both applied force intensity (i.e., high jet nozzle air velocity) and biofilm properties (i.e., low viscosity and low air-biofilm surface tension and thickness) intensify biofilm disruption by generating large interfacial instabilities.
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Shimada T, Yokoyama Y, Anzai T, Yamamoto K, Ishihama A. Regulatory Role of PlaR (YiaJ) for Plant Utilization in Escherichia coli K-12. Sci Rep 2019; 9:20415. [PMID: 31892694 PMCID: PMC6958661 DOI: 10.1038/s41598-019-56886-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022] Open
Abstract
Outside a warm-blooded animal host, the enterobacterium Escherichia coli K-12 is also able to grow and survive in stressful nature. The major organic substance in nature is plant, but the genetic system of E. coli how to utilize plant-derived materials as nutrients is poorly understood. Here we describe the set of regulatory targets for uncharacterized IclR-family transcription factor YiaJ on the E. coli genome, using gSELEX screening system. Among a total of 18 high-affinity binding targets of YiaJ, the major regulatory target was identified to be the yiaLMNOPQRS operon for utilization of ascorbate from fruits and galacturonate from plant pectin. The targets of YiaJ also include the genes involved in the utilization for other plant-derived materials as nutrients such as fructose, sorbitol, glycerol and fructoselysine. Detailed in vitro and in vivo analyses suggest that L-ascorbate and α-D-galacturonate are the effector ligands for regulation of YiaJ function. These findings altogether indicate that YiaJ plays a major regulatory role in expression of a set of the genes for the utilization of plant-derived materials as nutrients for survival. PlaR was also suggested to play protecting roles of E. coli under stressful environments in nature, including the formation of biofilm. We then propose renaming YiaJ to PlaR (regulator of plant utilization). The natural hosts of enterobacterium Escherichia coli are warm-blooded animals, but even outside hosts, E. coli can survive even under stressful environments. On earth, the most common organic materials to be used as nutrients by E. coli are plant-derived components, but up to the present time, the genetic system of E. coli for plant utilization is poorly understand. In the course of gSELEX screening of the regulatory targets for hitherto uncharacterized TFs, we identified in this study the involvement of the IclR-family YiaJ in the regulation of about 20 genes or operons, of which the majority are related to the catabolism of plant-derived materials such as ascorbate, galacturonate, sorbitol, fructose and fructoselysine. Therefore, we propose to rename YiaJ to PlaR (regulator of plant utilization).
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Affiliation(s)
- Tomohiro Shimada
- Meiji University, School of Agriculture, Kawasaki, Kanagawa, 214-8571, Japan. .,Hosei University, Research Institute of Micro-Nano Technology, Koganei, Tokyo, 184-0003, Japan.
| | - Yui Yokoyama
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan
| | - Takumi Anzai
- Meiji University, School of Agriculture, Kawasaki, Kanagawa, 214-8571, Japan
| | - Kaneyoshi Yamamoto
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan
| | - Akira Ishihama
- Hosei University, Research Institute of Micro-Nano Technology, Koganei, Tokyo, 184-0003, Japan. .,Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan.
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Engin AB, Engin A. Nanoantibiotics: A Novel Rational Approach to Antibiotic Resistant Infections. Curr Drug Metab 2019; 20:720-741. [DOI: 10.2174/1389200220666190806142835] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/19/2019] [Accepted: 07/19/2019] [Indexed: 01/09/2023]
Abstract
Background:The main drawbacks for using conventional antimicrobial agents are the development of multiple drug resistance due to the use of high concentrations of antibiotics for extended periods. This vicious cycle often generates complications of persistent infections, and intolerable antibiotic toxicity. The problem is that while all new discovered antimicrobials are effective and promising, they remain as only short-term solutions to the overall challenge of drug-resistant bacteria.Objective:Recently, nanoantibiotics (nAbts) have been of tremendous interest in overcoming the drug resistance developed by several pathogenic microorganisms against most of the commonly used antibiotics. Compared with free antibiotic at the same concentration, drug delivered via a nanoparticle carrier has a much more prominent inhibitory effect on bacterial growth, and drug toxicity, along with prolonged drug release. Additionally, multiple drugs or antimicrobials can be packaged within the same smart polymer which can be designed with stimuli-responsive linkers. These stimuli-responsive nAbts open up the possibility of creating multipurpose and targeted antimicrobials. Biofilm formation still remains the leading cause of conventional antibiotic treatment failure. In contrast to conventional antibiotics nAbts easily penetrate into the biofilm, and selectively target biofilm matrix constituents through the introduction of bacteria specific ligands. In this context, various nanoparticles can be stabilized and functionalized with conventional antibiotics. These composites have a largely enhanced bactericidal efficiency compared to the free antibiotic.Conclusion:Nanoparticle-based carriers deliver antibiotics with better biofilm penetration and lower toxicity, thus combating bacterial resistance. However, the successful adaptation of nanoformulations to clinical practice involves a detailed assessment of their safety profiles and potential immunotoxicity.
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Affiliation(s)
- Ayse Basak Engin
- Faculty of Pharmacy, Department of Toxicology, Gazi University, Ankara, Turkey
| | - Atilla Engin
- Faculty of Medicine, Department of General Surgery, Gazi University, Ankara, Turkey
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Weiskerger CJ, Brandão J, Ahmed W, Aslan A, Avolio L, Badgley BD, Boehm AB, Edge TA, Fleisher JM, Heaney CD, Jordao L, Kinzelman JL, Klaus JS, Kleinheinz GT, Meriläinen P, Nshimyimana JP, Phanikumar MS, Piggot AM, Pitkänen T, Robinson C, Sadowsky MJ, Staley C, Staley ZR, Symonds EM, Vogel LJ, Yamahara KM, Whitman RL, Solo-Gabriele HM, Harwood VJ. Impacts of a changing earth on microbial dynamics and human health risks in the continuum between beach water and sand. WATER RESEARCH 2019; 162:456-470. [PMID: 31301475 DOI: 10.1016/j.watres.2019.07.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 05/16/2023]
Abstract
Although infectious disease risk from recreational exposure to waterborne pathogens has been an active area of research for decades, beach sand is a relatively unexplored habitat for the persistence of pathogens and fecal indicator bacteria (FIB). Beach sand, biofilms, and water all present unique advantages and challenges to pathogen introduction, growth, and persistence. These dynamics are further complicated by continuous exchange between sand and water habitats. Models of FIB and pathogen fate and transport at beaches can help predict the risk of infectious disease from beach use, but knowledge gaps with respect to decay and growth rates of pathogens in beach habitats impede robust modeling. Climatic variability adds further complexity to predictive modeling because extreme weather events, warming water, and sea level change may increase human exposure to waterborne pathogens and alter relationships between FIB and pathogens. In addition, population growth and urbanization will exacerbate contamination events and increase the potential for human exposure. The cumulative effects of anthropogenic changes will alter microbial population dynamics in beach habitats and the assumptions and relationships used in quantitative microbial risk assessment (QMRA) and process-based models. Here, we review our current understanding of microbial populations and transport dynamics across the sand-water continuum at beaches, how these dynamics can be modeled, and how global change factors (e.g., climate and land use) should be integrated into more accurate beachscape-based models.
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Affiliation(s)
- Chelsea J Weiskerger
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
| | - João Brandão
- Department of Environmental Health, National Institute of Health Dr. Ricardo Jorge, Lisboa, Portugal; Centre for Environmental and Marine Studies (CESAM) - Department of Animal Biology, University of Lisboa, Lisboa, Portugal.
| | - Warish Ahmed
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Land and Water, Ecosciences Precinct, 41 Boogo Road, Dutton Park, Old, 4102, Australia
| | - Asli Aslan
- Department of Environmental Health Sciences, Georgia Southern University, Statesboro, GA, USA
| | - Lindsay Avolio
- Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Brian D Badgley
- School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Alexandria B Boehm
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Thomas A Edge
- Department of Biology, McMaster University, Ontario, Canada
| | - Jay M Fleisher
- College of Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Christopher D Heaney
- Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Luisa Jordao
- Department of Environmental Health, National Institute of Health Dr. Ricardo Jorge, Lisboa, Portugal
| | | | - James S Klaus
- Department of Marine Geosciences, University of Miami, Miami, FL, USA
| | | | - Päivi Meriläinen
- Department of Health Security, National Institute for Health and Welfare, Kuopio, Finland
| | | | - Mantha S Phanikumar
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
| | - Alan M Piggot
- Department of Earth and Environment, Florida International University, Miami, FL, USA
| | - Tarja Pitkänen
- Department of Health Security, National Institute for Health and Welfare, Kuopio, Finland
| | - Clare Robinson
- Department of Civil and Environmental Engineering, Western University, London, Ontario, Canada
| | - Michael J Sadowsky
- BioTechnology Institute and Departments of Soil, Water, & Climate, and Plant and Microbial Biology, University of Minnesota, St. Paul, MN, USA
| | | | | | - Erin M Symonds
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - Laura J Vogel
- Department of Civil and Environmental Engineering, Western University, London, Ontario, Canada
| | - Kevan M Yamahara
- Monterrey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Richard L Whitman
- Great Lakes Science Center, United States Geological Survey, Chesterton, IN, USA
| | - Helena M Solo-Gabriele
- Department of Civil, Architectural, and Environmental Engineering, University of Miami, Coral Gables, FL, USA
| | - Valerie J Harwood
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
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Charlton SGV, White MA, Jana S, Eland LE, Jayathilake PG, Burgess JG, Chen J, Wipat A, Curtis TP. Regulating, Measuring, and Modeling the Viscoelasticity of Bacterial Biofilms. J Bacteriol 2019; 201:e00101-19. [PMID: 31182499 PMCID: PMC6707926 DOI: 10.1128/jb.00101-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Biofilms occur in a broad range of environments under heterogeneous physicochemical conditions, such as in bioremediation plants, on surfaces of biomedical implants, and in the lungs of cystic fibrosis patients. In these scenarios, biofilms are subjected to shear forces, but the mechanical integrity of these aggregates often prevents their disruption or dispersal. Biofilms' physical robustness is the result of the multiple biopolymers secreted by constituent microbial cells which are also responsible for numerous biological functions. A better understanding of the role of these biopolymers and their response to dynamic forces is therefore crucial for understanding the interplay between biofilm structure and function. In this paper, we review experimental techniques in rheology, which help quantify the viscoelasticity of biofilms, and modeling approaches from soft matter physics that can assist our understanding of the rheological properties. We describe how these methods could be combined with synthetic biology approaches to control and investigate the effects of secreted polymers on the physical properties of biofilms. We argue that without an integrated approach of the three disciplines, the links between genetics, composition, and interaction of matrix biopolymers and the viscoelastic properties of biofilms will be much harder to uncover.
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Affiliation(s)
- Samuel G V Charlton
- School of Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Michael A White
- Interdisciplinary Computing & Complex BioSystems Research Group, School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Saikat Jana
- School of Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Lucy E Eland
- Interdisciplinary Computing & Complex BioSystems Research Group, School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - J Grant Burgess
- School of Natural & Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jinju Chen
- School of Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Anil Wipat
- Interdisciplinary Computing & Complex BioSystems Research Group, School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Thomas P Curtis
- School of Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
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Valentin JD, Qin XH, Fessele C, Straub H, van der Mei HC, Buhmann MT, Maniura-Weber K, Ren Q. Substrate viscosity plays an important role in bacterial adhesion under fluid flow. J Colloid Interface Sci 2019; 552:247-257. [DOI: 10.1016/j.jcis.2019.05.043] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/08/2019] [Accepted: 05/13/2019] [Indexed: 01/08/2023]
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107
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Petridis X, Busanello FH, So MVR, Dijkstra RJB, Sharma PK, van der Sluis LWM. Chemical efficacy of several NaOCl concentrations on biofilms of different architecture: new insights on NaOCl working mechanisms. Int Endod J 2019; 52:1773-1788. [PMID: 31389008 PMCID: PMC7328853 DOI: 10.1111/iej.13198] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/03/2019] [Indexed: 01/20/2023]
Abstract
AIM To investigate the anti-biofilm efficacy and working mechanism of several NaOCl concentrations on dual-species biofilms of different architecture as well as the changes induced on the architecture of the remaining biofilms. METHODOLOGY Streptococcus oralis J22 and Actinomyces naeslundii T14V-J1 were co-cultured under different growth conditions on saliva-coated hydroxyapatite discs. A constant-depth film fermenter (CDFF) was used to grow steady-state, four-day mature biofilms (dense architecture). Biofilms were grown under static conditions for 4 days within a confined space (less dense architecture). Twenty microlitres of buffer, 2-, 5-, and 10% NaOCl were applied statically on the biofilms for 60 s. Biofilm disruption and dissolution, as well as bubble formation, were evaluated with optical coherence tomography (OCT). The viscoelastic profile of the biofilms post-treatment was assessed with low load compression testing (LLCT). The bacteria/extracellular polysaccharide (EPS) content of the biofilms was examined through confocal laser scanning microscopy (CLSM). OCT, LLCT and CLSM data were analysed through one-way analysis of variance (ANOVA) and Tukey's HSD post-hoc test. Linear regression analysis was performed to test the correlation between bubble formation and NaOCl concentration. The level of significance was set at a < 0.05. RESULTS The experimental hypothesis according to which enhanced biofilm disruption, dissolution and bubble formation were anticipated with increasing NaOCl concentration was generally confirmed in both biofilm types. Distinct differences between the two biofilm types were noted with regard to NaOCl anti-biofilm efficiency as well as the effect that the several NaOCl concentrations had on the viscoelasticity profile and the bacteria/EPS content. Along with the bubble generation patterns observed, these led to the formulation of a concentration and biofilm structure-dependent theory of biofilm removal. CONCLUSIONS Biofilm architecture seems to be an additional determining factor of the penetration capacity of NaOCl, and consequently of its anti-biofilm efficiency.
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Affiliation(s)
- X Petridis
- Department of Conservative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - F H Busanello
- Conservative Dentistry Department, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - M V R So
- Conservative Dentistry Department, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - R J B Dijkstra
- Department of Conservative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - P K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - L W M van der Sluis
- Department of Conservative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Das T, Paino D, Manoharan A, Farrell J, Whiteley G, Kriel FH, Glasbey T, Manos J. Conditions Under Which Glutathione Disrupts the Biofilms and Improves Antibiotic Efficacy of Both ESKAPE and Non-ESKAPE Species. Front Microbiol 2019; 10:2000. [PMID: 31543871 PMCID: PMC6730566 DOI: 10.3389/fmicb.2019.02000] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 08/15/2019] [Indexed: 01/07/2023] Open
Abstract
Bacterial antibiotic resistance has increased in recent decades, raising concerns in hospital and community settings. Novel, innovative strategies are needed to eradicate bacteria, particularly within biofilms, and diminish the likelihood of recurrence. In this study, we investigated whether glutathione (GSH) can act as a biofilm disruptor, and enhance antibiotic effectiveness against various bacterial pathogens. Biological levels (10 mM) of GSH did not have a significant effect in inhibiting growth or disrupting the biofilm in four out of six species tested. However, exposure to 30 mM GSH showed >50% decrease in growth for all bacterial species, with almost 100% inhibition of Streptococcus pyogenes and an average of 94-52% inhibition for Escherichia coli, Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive S. aureus (MSSA) and multi-drug resistant Acinetobacter baumannii (MRAB) isolates, respectively. Klebsiella pneumoniae and Enterobacter sp. isolates were however, highly resistant to 30 mM GSH. With respect to biofilm viability, all species exhibited a >50% decrease in viability with 30 mM GSH, with confocal imaging showing considerable change in the biofilm architecture of MRAB isolates. The mechanism of GSH-mediated biofilm disruption is possibly due to a concentration-dependent increase in GSH acidity that triggers cleaving of the matrix components. Enzymatic treatment of MRAB revealed that eDNA and polysaccharides are essential for biofilm stability and eDNA removal enhanced amikacin efficiency. Combination of GSH, amikacin and DNase-I showed the greatest reduction in MRAB biofilm viability. Additionally, GSH alone and in combination with amikacin fostered human fibroblast cell (HFF-1) growth and confluence while inhibiting MRAB adhesion and colonization.
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Affiliation(s)
- Theerthankar Das
- Department of Infectious Diseases and Immunology, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Denis Paino
- Department of Infectious Diseases and Immunology, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Arthika Manoharan
- Department of Infectious Diseases and Immunology, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Jessica Farrell
- Department of Infectious Diseases and Immunology, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Greg Whiteley
- Whiteley Corporation, North Sydney, NSW, Australia
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | | | | | - Jim Manos
- Department of Infectious Diseases and Immunology, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
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110
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A Dual-Species Biofilm with Emergent Mechanical and Protective Properties. J Bacteriol 2019; 201:JB.00670-18. [PMID: 30833350 DOI: 10.1128/jb.00670-18] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/23/2019] [Indexed: 12/14/2022] Open
Abstract
Many microbes coexist within biofilms, or multispecies communities of cells encased in an extracellular matrix. However, little is known about the microbe-microbe interactions relevant for creating these structures. In this study, we explored a striking dual-species biofilm between Bacillus subtilis and Pantoea agglomerans that exhibited characteristics that were not predictable from previous work examining monoculture biofilms. Coculture wrinkle formation required a P. agglomerans exopolysaccharide as well as the B. subtilis amyloid-like protein TasA. Unexpectedly, other B. subtilis matrix components essential for monoculture biofilm formation were not necessary for coculture wrinkling (e.g., the exopolysaccharide EPS, the hydrophobin BslA, and cell chaining). In addition, B. subtilis cell chaining prevented coculture wrinkling, even though chaining was previously associated with more robust monoculture biofilms. We also observed that increasing the relative proportion of P. agglomerans (which forms completely featureless monoculture colonies) increased coculture wrinkling. Using microscopy and rheology, we observed that these two bacteria assemble into an organized layered structure that reflects the physical properties of both monocultures. This partitioning into distinct regions negatively affected the survival of P. agglomerans while also serving as a protective mechanism in the presence of antibiotic stress. Taken together, these data indicate that studying cocultures is a productive avenue to identify novel mechanisms that drive the formation of structured microbial communities.IMPORTANCE In the environment, many microbes form biofilms. However, the interspecies interactions underlying bacterial coexistence within these biofilms remain understudied. Here, we mimic environmentally relevant biofilms by studying a dual-species biofilm formed between Bacillus subtilis and Pantoea agglomerans and subjecting the coculture to chemical and physical stressors that it may experience in the natural world. We determined that both bacteria contribute structural elements to the coculture, which is reflected in its overall viscoelastic behavior. Existence within the coculture can be either beneficial or detrimental depending on the context. Many of the features and determinants of the coculture biofilm appear distinct from those identified in monoculture biofilm studies, highlighting the importance of characterizing multispecies consortia to understand naturally occurring bacterial interactions.
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Cattò C, Cappitelli F. Testing Anti-Biofilm Polymeric Surfaces: Where to Start? Int J Mol Sci 2019; 20:E3794. [PMID: 31382580 PMCID: PMC6696330 DOI: 10.3390/ijms20153794] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/02/2019] [Indexed: 12/11/2022] Open
Abstract
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.
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Affiliation(s)
- Cristina Cattò
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy
| | - Francesca Cappitelli
- Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy.
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Petridis X, Busanello FH, So MVR, Dijkstra RJB, Sharma PK, van der Sluis LWM. Factors affecting the chemical efficacy of 2% sodium hypochlorite against oral steady-state dual-species biofilms: Exposure time and volume application. Int Endod J 2019; 52:1182-1195. [PMID: 30807649 PMCID: PMC7328852 DOI: 10.1111/iej.13102] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 02/22/2019] [Indexed: 01/06/2023]
Abstract
AIM To study the influence of time and volume of 2% sodium hypochlorite (NaOCl) on biofilm removal and to investigate the changes induced on the biofilm architecture. Steady-state, dual-species biofilms of standardized thickness and a realistic contact surface area between biofilms and NaOCl were used. METHODOLOGY Streptococcus oralis J22 and Actinomyces naeslundii T14V-J1 biofilms were grown on saliva-coated hydroxyapatite discs within sample holders in the Constant Depth Film Fermenter (CDFF) for 96 h. Two per cent NaOCl was statically applied for three different time intervals (60, 120 and 300 s) and in two different volumes (20 and 40 μL) over the biofilm samples. The diffusion-driven effects of time and volume on biofilm disruption and dissolution were assessed with Optical Coherence Tomography (OCT). Structural changes of the biofilms treated with 2% NaOCl were studied with Confocal Laser Scanning Microscopy (CLSM) and Low Load Compression Testing (LLCT). A two-way analysis of variance (2-way anova) was performed, enabling the effect of each independent variable as well as their interaction on the outcome measures. RESULTS Optical coherence tomography revealed that by increasing the exposure time and volume of 2% NaOCl, both biofilm disruption and dissolution significantly increased. Analysis of the interaction between the two independent variables revealed that by increasing the volume of 2% NaOCl, significant biofilm dissolution could be achieved in less time. Examination of the architecture of the remaining biofilms corroborated the EPS-lytic action of 2% NaOCl, especially when greater volumes were applied. The viscoelastic analysis of the 2% NaOCl-treated biofilms revealed that the preceding application of higher volumes could impact their subsequent removal. CONCLUSIONS Time and volume of 2% NaOCl application should be taken into account for maximizing the anti-biofilm efficiency of the irrigant and devising targeted disinfecting regimes against remaining biofilms.
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Affiliation(s)
- X. Petridis
- Department of Conservative DentistryCenter for Dentistry and Oral HygieneUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - F. H. Busanello
- Conservative Dentistry DepartmentSchool of DentistryFederal University of Rio Grande do SulPorto AlegreRio Grande do SulBrazil
| | - M. V. R. So
- Conservative Dentistry DepartmentSchool of DentistryFederal University of Rio Grande do SulPorto AlegreRio Grande do SulBrazil
| | - R. J. B. Dijkstra
- Department of Conservative DentistryCenter for Dentistry and Oral HygieneUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - P. K. Sharma
- Department of Biomedical EngineeringUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - L. W. M. van der Sluis
- Department of Conservative DentistryCenter for Dentistry and Oral HygieneUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
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Hou J, Wang C, Rozenbaum RT, Gusnaniar N, de Jong ED, Woudstra W, Geertsema-Doornbusch GI, Atema-Smit J, Sjollema J, Ren Y, Busscher HJ, van der Mei HC. Bacterial Density and Biofilm Structure Determined by Optical Coherence Tomography. Sci Rep 2019; 9:9794. [PMID: 31278369 PMCID: PMC6611762 DOI: 10.1038/s41598-019-46196-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/14/2019] [Indexed: 12/19/2022] Open
Abstract
Optical-coherence-tomography (OCT) is a non-destructive tool for biofilm imaging, not requiring staining, and used to measure biofilm thickness and putative comparison of biofilm structure based on signal intensity distributions in OCT-images. Quantitative comparison of biofilm signal intensities in OCT-images, is difficult due to the auto-scaling applied in OCT-instruments to ensure optimal quality of individual images. Here, we developed a method to eliminate the influence of auto-scaling in order to allow quantitative comparison of biofilm densities in different images. Auto- and re-scaled signal intensities could be qualitatively interpreted in line with biofilm characteristics for single and multi-species biofilms of different strains and species (cocci and rod-shaped organisms), demonstrating qualitative validity of auto- and re-scaling analyses. However, specific features of pseudomonas and oral multi-species biofilms were more prominently expressed after re-scaling. Quantitative validation was obtained by relating average auto- and re-scaled signal intensities across biofilm images with volumetric-bacterial-densities in biofilms, independently obtained using enumeration of bacterial numbers per unit biofilm volume. The signal intensities in auto-scaled biofilm images did not significantly relate with volumetric-bacterial-densities, whereas re-scaled intensities in images of biofilms of widely different strains and species increased linearly with independently determined volumetric-bacterial-densities in the biofilms. Herewith, the proposed re-scaling of signal intensity distributions in OCT-images significantly enhances the possibilities of biofilm imaging using OCT.
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Affiliation(s)
- Jiapeng Hou
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Can Wang
- University of Groningen and University Medical Center Groningen, Department of Orthodontics, Hanzeplein 1, 9713, GZ, Groningen, The Netherlands
| | - René T Rozenbaum
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Niar Gusnaniar
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Ed D de Jong
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Willem Woudstra
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Gésinda I Geertsema-Doornbusch
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Jelly Atema-Smit
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Jelmer Sjollema
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Yijin Ren
- University of Groningen and University Medical Center Groningen, Department of Orthodontics, Hanzeplein 1, 9713, GZ, Groningen, The Netherlands
| | - Henk J Busscher
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands
| | - Henny C van der Mei
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700, AD, Groningen, The Netherlands.
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114
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Hengge R. Targeting Bacterial Biofilms by the Green Tea Polyphenol EGCG. Molecules 2019; 24:molecules24132403. [PMID: 31261858 PMCID: PMC6650844 DOI: 10.3390/molecules24132403] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/20/2022] Open
Abstract
Bacterial biofilms are multicellular aggregates in which cells are embedded in an extracellular matrix of self-produced biopolymers. Being refractory to antibiotic treatment and host immune systems, biofilms are involved in most chronic infections, and anti-biofilm agents are being searched for urgently. Epigallocatechin-3-gallate (EGCG) was recently shown to act against biofilms by strongly interfering with the assembly of amyloid fibres and the production of phosphoethanolamin-modified cellulose fibrils. Mechanistically, this includes a direct inhibition of the fibre assembly, but also triggers a cell envelope stress response that down-regulates the synthesis of these widely occurring biofilm matrix polymers. Based on its anti-amyloidogenic properties, EGCG seems useful against biofilms involved in cariogenesis or chronic wound infection. However, EGCG seems inefficient against or may even sometimes promote biofilms which rely on other types of matrix polymers, suggesting that searching for 'magic bullet' anti-biofilm agents is an unrealistic goal. Combining molecular and ecophysiological aspects in this review also illustrates why plants control the formation of biofilms on their surfaces by producing anti-amyloidogenic compounds such as EGCG. These agents are not only helpful in combating certain biofilms in chronic infections but even seem effective against the toxic amyloids associated with neuropathological diseases.
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Affiliation(s)
- Regine Hengge
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10155 Berlin, Germany.
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115
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Horvat M, Pannuri A, Romeo T, Dogsa I, Stopar D. Viscoelastic response of Escherichia coli biofilms to genetically altered expression of extracellular matrix components. SOFT MATTER 2019; 15:5042-5051. [PMID: 31179461 DOI: 10.1039/c9sm00297a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
How the viscoelastic properties of the extracellular matrix affect the various biological functions conferred by biofilms is an important question in microbiology. In this study, the viscoelastic response of Escherichia coli biofilms to the genetically altered expression of extracellular matrix components was studied. Biofilms of the wild type E. coli MG1655 and its mutant strains producing different amounts of extracellular matrix components (curli, colanic acid, and poly-β-1,6-N-acetyl-d-glucosamine) were used to examine the viscoelastic behavior of biofilms grown at the solid-atmosphere interface. The results suggest that the presence of curli proteins dominates biofilm mechanical behavior. The rheological data indicate that the cohesive energy of the biofilm was the highest in the wild type strain. The results demonstrate the importance of extracellular matrix composition for biofilm mechanical properties. We propose that by genetically altering the expression of extracellular matrix polymers, bacteria are able to modulate the mechanical properties of their local environment in accordance with bulk environmental conditions.
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Affiliation(s)
- Maruša Horvat
- University of Ljubljana, Biotechnical Faculty, Chair of Microbiology, Department of Food Science and Technology, Večna pot 111, 1000 Ljubljana, Slovenia.
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116
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Activity of Antibiotics against Staphylococcus aureus in an In Vitro Model of Biofilms in the Context of Cystic Fibrosis: Influence of the Culture Medium. Antimicrob Agents Chemother 2019; 63:AAC.00602-19. [PMID: 31036685 DOI: 10.1128/aac.00602-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 04/20/2019] [Indexed: 01/27/2023] Open
Abstract
Staphylococcus aureus is a highly prevalent pathogen in the respiratory tract of young patients with cystic fibrosis (CF) and causes biofilm-related infections. Here, we set up an in vitro model of a biofilm grown in Trypticase soy broth supplemented with glucose and NaCl (TGN) or in artificial sputum medium (ASM) and used it to evaluate on a pharmacodynamic basis the activity of antibiotics used in CF patients and active on staphylococci (meropenem, vancomycin, azithromycin, linezolid, rifampin, ciprofloxacin, tobramycin). Rheological studies showed that ASM was more elastic than viscous, as was also observed for sputa from CF patients, with elastic and viscous moduli being, respectively, similar to and slightly lower than those of CF sputa. Biofilms formed by methicillin-sensitive S. aureus strain ATCC 25923 and methicillin-resistant S. aureus strain ATCC 33591 reached maturity after 24 h, with biomass (measured by crystal violet staining) and metabolic activity (assessed by following resazurin metabolization) being lower in ASM than in TGN and viability (assessed by bacterial counts) being similar in both media. Full concentration-response curves of antibiotics obtained after 24 h of incubation of biofilms showed that all antibiotics were drastically less potent and less efficient in ASM than in TGN toward viability, metabolic activity, and biomass. Tobramycin selected for small-colony variants, specifically in biofilms grown in ASM; the auxotrophism of these variants could not be established. These data highlight the major influence exerted by the culture medium on S. aureus responsiveness to antibiotics in biofilms. The use of ASM may help to determine effective drug concentrations or to evaluate new therapeutic options against biofilms in CF patients.
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117
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López-Guerra EA, Shen H, Solares SD, Shuai D. Acquisition of time-frequency localized mechanical properties of biofilms and single cells with high spatial resolution. NANOSCALE 2019; 11:8918-8929. [PMID: 31017130 DOI: 10.1039/c8nr10287b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Biofilms are a cluster of bacteria embedded in extracellular polymeric substances (EPS) that contain a complex composition of polysaccharides, proteins, and extracellular DNA (eDNA). Desirable mechanical properties of the biofilms are critical for their survival, propagation, and dispersal, and the response of mechanical properties to different treatment conditions also sheds light on biofilm control and eradication in vivo and on engineering surfaces. However, it is challenging yet important to investigate mechanical behaviors of biofilms with a high spatial resolution because biofilms are very heterogeneous. Moreover, biofilms are viscoelastic, and their time-dependent mechanical behavior is difficult to capture. Herein, we develop a powerful technique that combines the high spatial resolution of an atomic force microscope (AFM) with a rigorous history-dependent viscoelastic analysis to deliver highly spatial-localized biofilm properties within a wide time-frequency window. By exploiting the use of static force spectroscopy in combination with an appropriate viscoelastic framework, we highlight the intensive amount of time-dependent information experimentally available that has been largely overlooked. It is shown that this technique provides a detailed nanorheological signature of the biofilms even at the single-cell level. We share the computational routines that would allow any user to perform the analysis from experimental raw data. The detailed localization of mechanical properties in space and in time-frequency domain provides insights into the understanding of biofilm stability, cohesiveness, dispersal, and control.
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Affiliation(s)
- Enrique A López-Guerra
- Department of Civil and Environmental Engineering, The George Washington University, Washington, DC 20052, USA.
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118
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Hwang G, Paula AJ, Hunter EE, Liu Y, Babeer A, Karabucak B, Stebe K, Kumar V, Steager E, Koo H. Catalytic antimicrobial robots for biofilm eradication. Sci Robot 2019; 4:eaaw2388. [PMID: 31531409 PMCID: PMC6748647 DOI: 10.1126/scirobotics.aaw2388] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Magnetically driven robots can perform complex functions in biological settings with minimal destruction. However, robots designed to damage deleterious biostructures could also have important impact. In particular, there is an urgent need for new strategies to eradicate bacterial biofilms as we approach a post-antibiotic era. Biofilms are intractable and firmly attached structures ubiquitously associated with drug-resistant infections and destruction of surfaces. Existing treatments are inadequate to both kill and remove bacteria leading to reinfection. Here we design catalytic antimicrobial robots (CARs) that precisely and controllably kill, degrade and remove biofilms with remarkable efficiency. CARs exploit iron oxide nanoparticles (NPs) with dual catalytic-magnetic functionality that (i) generate bactericidal free radicals, (ii) breakdown the biofilm exopolysaccharide (EPS) matrix, and (iii) remove the fragmented biofilm debris via magnetic field driven robotic assemblies. We develop two distinct CAR platforms. The first platform, the biohybrid CAR, is formed from NPs and biofilm degradation products. After catalytic bacterial killing and EPS disruption, magnetic field gradients assemble NPs and the biodegraded products into a plow-like superstructure. When driven with an external magnetic field, the biohybrid CAR completely removes biomass in a controlled manner, preventing biofilm regrowth. Biohybrid CARs can be swept over broad swathes of surface or can be moved over well-defined paths for localized removal with microscale precision. The second platform, the 3D molded CAR, is a polymeric soft robot with embedded catalytic-magnetic NPs, formed in a customized 3D printed mold to perform specific tasks in enclosed domains. Vane-shaped CARs remove biofilms from curved walls of cylindrical tubes, and helicoid-shaped CARs drill through biofilm clogs, while simultaneously killing bacteria. In addition, we demonstrate applications of CARs to target highly confined anatomical surfaces in the interior of human teeth. These 'kill-degrade-and-remove' CARs systems could have significant impact in fighting persistent biofilm-infections and in mitigating biofouling of medical devices and diverse surfaces.
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Affiliation(s)
- Geelsu Hwang
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, USA
| | - Amauri J. Paula
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, USA
- Solid-Biological Interface Group (SolBIN), Department of Physics, Universidade Federal do Ceará, Fortaleza-CE, Brazil
| | - Elizabeth E. Hunter
- GRASP Laboratory, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, USA
| | - Yuan Liu
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, USA
| | - Alaa Babeer
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, USA
- Department of Endodontics, School of Dental Medicine, University of Pennsylvania, USA
| | - Bekir Karabucak
- Department of Endodontics, School of Dental Medicine, University of Pennsylvania, USA
| | - Kathleen Stebe
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Vijay Kumar
- Department of Endodontics, School of Dental Medicine, University of Pennsylvania, USA
| | - Edward Steager
- Department of Endodontics, School of Dental Medicine, University of Pennsylvania, USA
| | - Hyun Koo
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, USA
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119
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Role of Viscoelasticity in Bacterial Killing by Antimicrobials in Differently Grown Pseudomonas aeruginosa Biofilms. Antimicrob Agents Chemother 2019; 63:AAC.01972-18. [PMID: 30745390 DOI: 10.1128/aac.01972-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/28/2018] [Indexed: 01/04/2023] Open
Abstract
Pseudomonas aeruginosa colonizes the sputum of most adult cystic fibrosis patients, forming difficult-to-eradicate biofilms in which bacteria are protected in their self-produced extracellular polymeric substance (EPS) matrices. EPS provide biofilms with viscoelastic properties, causing time-dependent relaxation after stress-induced deformation, according to multiple characteristic time constants. These time constants reflect different biofilm (matrix) components. Since the viscoelasticity of biofilms has been related to antimicrobial penetration but not yet bacterial killing, this study aims to relate killing of P. aeruginosa, in its biofilm mode of growth, by three antimicrobials to biofilm viscoelasticity. P. aeruginosa biofilms were grown for 18 h in a constant-depth film fermenter, with mucin-containing artificial sputum medium (ASM+), artificial sputum medium without mucin (ASM-), or Luria-Bertani (LB) broth; this yielded 100-μm-thick biofilms that differed in their amounts of matrix environmental DNA (eDNA) and polysaccharides. Low-load compression testing, followed by three-element Maxwell analyses, showed that the fastest relaxation component, associated with unbound water, was most important in LB-medium-grown biofilms. Slower components due to water with dissolved polysaccharides, insoluble polysaccharides, and eDNA were most important in the relaxation of ASM+-grown biofilms. ASM--grown biofilms showed intermediate stress relaxation. P. aeruginosa in LB-medium-grown biofilms was killed most by exposure to tobramycin, colistin, or an antimicrobial peptide, while ASM+ provided the most protective matrix, with less water and most insoluble polysaccharides and eDNA. In conclusion, stress relaxation of P. aeruginosa biofilms grown in different media revealed differences in matrix composition that, within the constraints of the antimicrobials and growth media applied, correlated with the matrix protection offered against different antimicrobials.
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120
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Yan J, Fei C, Mao S, Moreau A, Wingreen NS, Košmrlj A, Stone HA, Bassler BL. Mechanical instability and interfacial energy drive biofilm morphogenesis. eLife 2019; 8:43920. [PMID: 30848725 PMCID: PMC6453567 DOI: 10.7554/elife.43920] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/06/2019] [Indexed: 11/17/2022] Open
Abstract
Surface-attached bacterial communities called biofilms display a diversity of morphologies. Although structural and regulatory components required for biofilm formation are known, it is not understood how these essential constituents promote biofilm surface morphology. Here, using Vibrio cholerae as our model system, we combine mechanical measurements, theory and simulation, quantitative image analyses, surface energy characterizations, and mutagenesis to show that mechanical instabilities, including wrinkling and delamination, underlie the morphogenesis program of growing biofilms. We also identify interfacial energy as a key driving force for mechanomorphogenesis because it dictates the generation of new and the annihilation of existing interfaces. Finally, we discover feedback between mechanomorphogenesis and biofilm expansion, which shapes the overall biofilm contour. The morphogenesis principles that we discover in bacterial biofilms, which rely on mechanical instabilities and interfacial energies, should be generally applicable to morphogenesis processes in tissues in higher organisms. Engineers have long studied how mechanical instabilities cause patterns to form in inanimate materials, and recently more attention has been given to how such forces affect biological systems. For example, stresses can build up within a tissue if one layer grows faster than an adjacent layer. The tissue can release this stress by wrinkling, folding or creasing. Though ancient and single-celled, bacteria can also develop spectacular patterns when they exist in the lifestyle known as a biofilm: a community of cells adhered to a surface. But do mechanical instabilities drive the patterns seen in biofilms? To investigate, Yan, Fei, Mao et al. grew biofilms of the bacterium called Vibrio cholerae – which causes the disease cholera – on solid, non-growing ‘substrates’. This work revealed that as the biofilms grow, their expansion is constrained by the substrate, and this situation generates mechanical stresses. To release the stresses, the biofilm initially folds to form wrinkles. Later, as the biofilm expands further, small parts of it detach from the substrate to form blisters. The same forces that keep water droplets spherical (known as interfacial forces) dictate how the blisters evolve, interact, and eventually shape the expanding biofilm. Using these principles, Yan et al. could engineer the biofilm into desired shapes. Collectively, the results presented by Yan et al. connect the shape of the biofilm surface with its material properties, in particular its stiffness. Understanding this relationship could help researchers to develop new ways to remove harmful biofilms, such as those that cause disease or that damage underwater structures. The stiffness of biofilms is already known to affect how well bacteria can resist antibiotics. Future studies could look for new genes or compounds that change the material properties of a biofilm, thereby altering the biofilm surface.
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Affiliation(s)
- Jing Yan
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, United States.,Department of Molecular Biology, Princeton University, Princeton, United States
| | - Chenyi Fei
- Department of Molecular Biology, Princeton University, Princeton, United States
| | - Sheng Mao
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, United States
| | - Alexis Moreau
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, United States
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, United States
| | - Andrej Košmrlj
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, United States
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, United States
| | - Bonnie L Bassler
- Department of Molecular Biology, Princeton University, Princeton, United States.,The Howard Hughes Medical Institute, Chevy Chase, United States
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121
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Liou HC, Sabba F, Packman AI, Wells G, Balogun O. Nondestructive characterization of soft materials and biofilms by measurement of guided elastic wave propagation using optical coherence elastography. SOFT MATTER 2019; 15:575-586. [PMID: 30601536 DOI: 10.1039/c8sm01902a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Biofilms are soft multicomponent biological materials composed of microbial communities attached to surfaces. Despite the crucial relevance of biofilms to diverse industrial, medical, and environmental applications, the mechanical properties of biofilms are understudied. Moreover, most of the available techniques for the characterization of biofilm mechanical properties are destructive. Here, we detail a model-based approach developed to characterize the viscoelastic properties of soft materials and bacterial biofilms based on experimental data obtained using the nondestructive dynamic optical coherence elastography (OCE) technique. The model predicted the frequency- and geometry-dependent propagation velocities of elastic waves in a soft viscoelastic plate supported by a rigid substratum. Our numerical calculations suggest that the dispersion curves of guided waves recorded in thin soft plates by the dynamic OCE technique are dominated by guided waves, whose phase velocities depend on the viscoelastic properties and plate thickness. The numerical model was validated against experimental measurements in agarose phantom samples with different thicknesses and concentrations. The model was then used to interpret guided wave dispersion curves obtained by the OCE technique in bacterial biofilms developed in a rotating annular reactor, which allowed the quantitative characterization of biofilm shear modulus and viscosity. This study is the first to employ measurements of elastic wave propagation to characterize biofilms, and it provides a novel framework combining a theoretical model and an experimental approach for studying the relationship between the biofilm internal physical structure and mechanical properties.
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Affiliation(s)
- Hong-Cin Liou
- Mechanical Engineering Department, Northwestern University, Evanston, IL 60208, USA
| | - Fabrizio Sabba
- Civil and Environmental Engineering Department, Northwestern University, Evanston, IL 60208, USA.
| | - Aaron I Packman
- Civil and Environmental Engineering Department, Northwestern University, Evanston, IL 60208, USA.
| | - George Wells
- Civil and Environmental Engineering Department, Northwestern University, Evanston, IL 60208, USA.
| | - Oluwaseyi Balogun
- Mechanical Engineering Department, Northwestern University, Evanston, IL 60208, USA and Civil and Environmental Engineering Department, Northwestern University, Evanston, IL 60208, USA.
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122
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Ren Z, Kim D, Paula AJ, Hwang G, Liu Y, Li J, Daniell H, Koo H. Dual-Targeting Approach Degrades Biofilm Matrix and Enhances Bacterial Killing. J Dent Res 2019; 98:322-330. [PMID: 30678538 DOI: 10.1177/0022034518818480] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Biofilm formation is a key virulence factor responsible for a wide range of infectious diseases, including dental caries. Cariogenic biofilms are structured microbial communities embedded in an extracellular matrix that affords bacterial adhesion-cohesion and drug tolerance, making them difficult to treat using conventional antimicrobial monotherapy. Here, we investigated a multitargeted approach combining exopolysaccharide (EPS) matrix-degrading glucanohydrolases with a clinically used essential oils-based antimicrobial to potentiate antibiofilm efficacy. Our data showed that dextranase and mutanase can synergistically break down the EPS glucan matrix in preformed cariogenic biofilms, markedly enhancing bacterial killing by the antimicrobial agent (3-log increase versus antimicrobial alone). Further analyses revealed that an EPS-degrading/antimicrobial (EDA) approach disassembles the matrix scaffold, exposing the bacterial cells for efficient killing while concurrently causing cellular dispersion and "physical collapse" of the bacterial clusters. Unexpectedly, we found that the EDA approach can also selectively target the EPS-producing cariogenic bacteria Streptococcus mutans with higher killing specificity (versus other species) within mixed biofilms, disrupting their accumulation and promoting dominance of commensal bacteria. Together, these results demonstrate a dual-targeting approach that can enhance antibiofilm efficacy and precision by dismantling the EPS matrix and its protective microenvironment, amplifying the killing of pathogenic bacteria within.
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Affiliation(s)
- Z Ren
- 1 State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, P.R. China.,2 Biofilm Research Laboratories, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - D Kim
- 2 Biofilm Research Laboratories, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - A J Paula
- 1 State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, P.R. China.,3 Solid-Biological Interface Group (SolBIN), Departamento de Física, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - G Hwang
- 2 Biofilm Research Laboratories, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Y Liu
- 2 Biofilm Research Laboratories, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - J Li
- 1 State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, P.R. China
| | - H Daniell
- 4 Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - H Koo
- 2 Biofilm Research Laboratories, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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123
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Liu Y, Ren Z, Hwang G, Koo H. Therapeutic Strategies Targeting Cariogenic Biofilm Microenvironment. Adv Dent Res 2018; 29:86-92. [PMID: 29355421 DOI: 10.1177/0022034517736497] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cariogenic biofilms are highly structured microbial communities embedded in an extracellular matrix, a multifunctional scaffold that is essential for the existence of the biofilm lifestyle and full expression of virulence. The extracellular matrix provides the physical and biological properties that enhance biofilm adhesion and cohesion, as well as create a diffusion-modulating milieu, protecting the resident microbes and facilitating the formation of localized acidic pH niches. These biochemical properties pose significant challenges for the development of effective antibiofilm therapeutics to control dental caries. Conventional approaches focusing solely on antimicrobial activity or enhancing remineralization may not achieve maximal efficacy within the complex biofilm microenvironment. Recent approaches disrupting the biofilm microbial community and the microenvironment have emerged, including specific targeting of cariogenic pathogens, modulation of biofilm pH, and synergistic combination of bacterial killing and matrix degradation. Furthermore, new "smart" nanotechnologies that trigger drug release or activation in response to acidic pH are being developed that could enhance the efficacy of current and prospective chemical modalities. Therapeutic strategies that can locally disrupt the pathogenic niche by targeting the biofilm structure and its microenvironment to eliminate the embedded microorganism and facilitate the action of remineralizing agents may lead to enhanced and precise anticaries approaches.
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Affiliation(s)
- Y Liu
- 1 Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, Divisions of Pediatric Dentistry and Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Z Ren
- 1 Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, Divisions of Pediatric Dentistry and Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.,2 State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - G Hwang
- 1 Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, Divisions of Pediatric Dentistry and Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - H Koo
- 1 Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics, Divisions of Pediatric Dentistry and Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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124
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Viscoelastic and Textural Characteristics of Gels Obtained from Potato Starch Roasted under Several Temperature-Time Conditions. INT J POLYM SCI 2018. [DOI: 10.1155/2018/7606359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The influence of roasting conditions on the potato starch (PS) composition, solubility, crystallinity, gel-forming thermal profiles, and texture of the corresponding gels was studied. Thermorheological testing of roasted starches with (RPS) and without (RPSI) the soluble fraction was conducted on a stress-controlled rheometer. Texture profile analysis (TPA) was used to determine the RPS final gel texture. Solubility tests showed equivalent effects of starch roasting for samples treated at 190°C for 8 h (RPS190-8), 210°C for 6 h (RPS210-6), and 230°C for 4 h (RPS230-4). The apparent amylose content of RPS linearly increased with the decreasing degree of crystallinity. Elastic (G′) and viscous (G″) properties of RPS depended markedly on apparent amylose content and crystallinity. G′gel values of roasted starches linearly increased with the amylose content suggesting a promotion of the amylose breakdown with roasting temperature. Gels prepared with RPS roasted between 120 and 170°C exhibited intermediate strength and fully thermal reversible features. Roasting between 190 and 210°C favoured strong and fully thermal reversible gels. Although RPS230-4 gels exhibited similar strength to RPS190-8 and RPS210-4, no fully thermal reversible gels were obtained. The soluble fraction removal led to a drop the RPSI gels strength with increasing roasting temperature. No water syneresis was identified for RPS gels during one-week ageing, except for RPS230 gels. Relationships between textural parameters from TPA and viscoelastic gel properties determined by rheology were established.
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125
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Lin D, Cai P, Peacock CL, Wu Y, Gao C, Peng W, Huang Q, Liang W. Towards a better understanding of the aggregation mechanisms of iron (hydr)oxide nanoparticles interacting with extracellular polymeric substances: Role of pH and electrolyte solution. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:372-379. [PMID: 30029116 DOI: 10.1016/j.scitotenv.2018.07.136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/21/2018] [Accepted: 07/11/2018] [Indexed: 06/08/2023]
Abstract
Extracellular polymeric substances (EPS) are ubiquitous in the soil and water environment and interact strongly with mineral surfaces. However, these interactions and their impacts on the behavior and fate of minerals remain poorly understood. Here, for a better understanding of the colloidal stability of minerals in the environment, we investigated the aggregation of goethite (α-FeOOH) nanoparticles (NPs) in the presence of EPS from Bacillus subtilis under different environmental conditions (pH, ionic strength and ionic valence). Results showed that the aggregation processes of goethite NPs are determined by the solution chemistry, and the colloidal stability of goethite NPs is strongly influenced by the addition of EPS. In the absence of ionic strength, the addition of EPS promotes the aggregation of goethite NPs only when the pH (pH = 6) is less than the point of zero charge for the goethite nanoparticles (pHpzc ≈ 8). In the presence of ionic strength, the aggregation rate of goethite NPs increases with increasing concentration of NaCl, NaNO3 and Na2SO4 solutions, and after the addition of EPS solution, the critical coagulation concentrations (CCC) of goethite NPs are increased from 43.0, 56.7 and 0.39 mM to 168.0, 304.9 and 126.2 mM in the three electrolyte solutions, indicating that the addition of EPS inhibits the aggregation of goethite NPs. While in Na3PO4 solution, when the concentration of Na3PO4 solution ranged from 0 to 1 mM, the aggregation rate of goethite NPs increases first, followed by a decrease, and with the concentration of Na3PO4 solution exceeding 1 mM, the aggregation rate of goethite NPs increases again, due to the charge screening by sodium counter ions. This study provides a fundamental understanding of the behavior of goethite NPs in natural soil and water environments.
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Affiliation(s)
- Di Lin
- Department of Environmental Sciences, College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Peng Cai
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | | | - Yichao Wu
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Chunhui Gao
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Wanxi Peng
- Department of Environmental Sciences, College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Wei Liang
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
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126
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Jafari M, Desmond P, van Loosdrecht MCM, Derlon N, Morgenroth E, Picioreanu C. Effect of biofilm structural deformation on hydraulic resistance during ultrafiltration: A numerical and experimental study. WATER RESEARCH 2018; 145:375-387. [PMID: 30173098 DOI: 10.1016/j.watres.2018.08.036] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/14/2018] [Accepted: 08/18/2018] [Indexed: 06/08/2023]
Abstract
Biofilm formation in membrane systems negatively impacts the filtration system performances. This study evaluated how biofilm compression driven by permeate flow increases the hydraulic resistance and leads to reduction in permeate flux. We analysed the effect of biofilm compression on hydraulic resistance and permeate flux through computational models supported by experimental data. Biofilms with homogeneous surface structure were subjected to step-wise changes in flux and transmembrane pressure during compression and relaxation tests. Biofilm thickness under applied forces was measured non-invasively in-situ using optical coherence tomography (OCT). A numerical model of poroelasticity, which couples water flow through the biofilm with biofilm mechanics, was developed to correlate the structural deformation with biofilm hydraulics (permeability and resistance). The computational model enabled extracting mechanical and hydrological parameters corresponding to the experimental data. Homogeneous biofilms under elevated compression forces experienced a significant reduction in thickness while only a slight increase in resistance was observed. This shows that hydraulic resistance of homogeneous biofilms was affected more by permeability decrease due to pore closure than by a decrease in thickness. Both viscoelastic and elastoplastic models could describe well the permanent biofilm deformation. However, for biofilms under study, a simpler elastic model could also be used due to the small irreversible deformations. The elastic moduli fitting the measured data were in agreement with other reported values for biofilm under compression. Biofilm stiffening under larger flow-driven compression forces was observed and described numerically by correlating inversely the elastic modulus with biofilm porosity. The importance of this newly developed method lies in estimation of accurate biofilm mechanical parameters to be used in numerical models for both membrane filtration system and biofouling cleaning strategies. Such model can ultimately be used to identify optimal operating conditions for membrane system subjected to biofouling.
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Affiliation(s)
- Morez Jafari
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands.
| | - Peter Desmond
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, 8093, Zürich, Switzerland
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Nicolas Derlon
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland
| | - Eberhard Morgenroth
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, 8093, Zürich, Switzerland
| | - Cristian Picioreanu
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands
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Yan J, Moreau A, Khodaparast S, Perazzo A, Feng J, Fei C, Mao S, Mukherjee S, Košmrlj A, Wingreen NS, Bassler BL, Stone HA. Bacterial Biofilm Material Properties Enable Removal and Transfer by Capillary Peeling. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1804153. [PMID: 30368924 PMCID: PMC8865467 DOI: 10.1002/adma.201804153] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/30/2018] [Indexed: 05/22/2023]
Abstract
Biofilms, surface-attached communities of bacterial cells, are a concern in health and in industrial operations because of persistent infections, clogging of flows, and surface fouling. Extracellular matrices provide mechanical protection to biofilm-dwelling cells as well as protection from chemical insults, including antibiotics. Understanding how biofilm material properties arise from constituent matrix components and how these properties change in different environments is crucial for designing biofilm removal strategies. Here, using rheological characterization and surface analyses of Vibrio cholerae biofilms, it is discovered how extracellular polysaccharides, proteins, and cells function together to define biofilm mechanical and interfacial properties. Using insight gained from our measurements, a facile capillary peeling technology is developed to remove biofilms from surfaces or to transfer intact biofilms from one surface to another. It is shown that the findings are applicable to other biofilm-forming bacterial species and to multiple surfaces. Thus, the technology and the understanding that have been developed could potentially be employed to characterize and/or treat biofilm-related infections and industrial biofouling problems.
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Affiliation(s)
- Jing Yan
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
| | - Alexis Moreau
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
| | - Sepideh Khodaparast
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
| | - Antonio Perazzo
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
| | - Jie Feng
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
| | - Chenyi Fei
- Department of Molecular Biology, Princeton University, 329 Lewis Thomas Laboratory, Princeton, NJ, 08544, USA
| | - Sheng Mao
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
| | - Sampriti Mukherjee
- Department of Molecular Biology, Princeton University, 329 Lewis Thomas Laboratory, Princeton, NJ, 08544, USA
| | - Andrej Košmrlj
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, 329 Lewis Thomas Laboratory, Princeton, NJ, 08544, USA
| | - Bonnie L Bassler
- Department of Molecular Biology, Princeton University, 329 Lewis Thomas Laboratory, Princeton, NJ, 08544, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, D328 E-Quad, Olden St., Princeton, NJ, 08544, USA
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128
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Teirlinck E, Xiong R, Brans T, Forier K, Fraire J, Van Acker H, Matthijs N, De Rycke R, De Smedt SC, Coenye T, Braeckmans K. Laser-induced vapour nanobubbles improve drug diffusion and efficiency in bacterial biofilms. Nat Commun 2018; 9:4518. [PMID: 30375378 PMCID: PMC6207769 DOI: 10.1038/s41467-018-06884-w] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 10/02/2018] [Indexed: 02/07/2023] Open
Abstract
Hindered penetration of antibiotics through biofilms is one of the reasons for the alarming increase in bacterial tolerance to antibiotics. Here, we investigate the potential of laser-induced vapour nanobubbles (VNBs) formed around plasmonic nanoparticles to locally disturb biofilm integrity and improve antibiotics diffusion. Our results show that biofilms of both Gram-negative (Burkholderia multivorans, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria can be loaded with cationic 70-nm gold nanoparticles and that subsequent laser illumination results in VNB formation inside the biofilms. In all types of biofilms tested, VNB formation leads to substantial local biofilm disruption, increasing tobramycin efficacy up to 1-3 orders of magnitude depending on the organism and treatment conditions. Altogether, our results support the potential of laser-induced VNBs as a new approach to disrupt biofilms of a broad range of organisms, resulting in improved antibiotic diffusion and more effective biofilm eradication.
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Affiliation(s)
- Eline Teirlinck
- Laboratory of General Biochemistry and Physical Pharmacy, University of Ghent, Ghent, 9000, Belgium
- Centre for Nano- and Biophotonics, Ghent, 9000, Belgium
| | - Ranhua Xiong
- Laboratory of General Biochemistry and Physical Pharmacy, University of Ghent, Ghent, 9000, Belgium
- Centre for Nano- and Biophotonics, Ghent, 9000, Belgium
| | - Toon Brans
- Laboratory of General Biochemistry and Physical Pharmacy, University of Ghent, Ghent, 9000, Belgium
- Centre for Nano- and Biophotonics, Ghent, 9000, Belgium
| | - Katrien Forier
- Laboratory of General Biochemistry and Physical Pharmacy, University of Ghent, Ghent, 9000, Belgium
- Centre for Nano- and Biophotonics, Ghent, 9000, Belgium
- Laboratory of Toxicology, Ghent University Hospital, Ghent, 9000, Belgium
| | - Juan Fraire
- Laboratory of General Biochemistry and Physical Pharmacy, University of Ghent, Ghent, 9000, Belgium
- Centre for Nano- and Biophotonics, Ghent, 9000, Belgium
| | - Heleen Van Acker
- Laboratory of Pharmaceutical Microbiology, University of Ghent, Ghent, 9000, Belgium
| | - Nele Matthijs
- Laboratory of Pharmaceutical Microbiology, University of Ghent, Ghent, 9000, Belgium
| | - Riet De Rycke
- Department of Biomedical Molecular Biology, VIB Center for Inflammation Research, Ghent University, 9052, Ghent, Belgium
- Expertise Centre for Transmission Electron Microscopy, VIB BioImaging Core, Ghent University, Ghent, 9052, Belgium
| | - Stefaan C De Smedt
- Laboratory of General Biochemistry and Physical Pharmacy, University of Ghent, Ghent, 9000, Belgium
- Centre for Nano- and Biophotonics, Ghent, 9000, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, University of Ghent, Ghent, 9000, Belgium
| | - Kevin Braeckmans
- Laboratory of General Biochemistry and Physical Pharmacy, University of Ghent, Ghent, 9000, Belgium.
- Centre for Nano- and Biophotonics, Ghent, 9000, Belgium.
- IEMN UMR 8520, Université de Lille, Villeneuve d'Ascq, 59652, France.
- Laboratoire de Physique des Lasers, Atomes et Molécules UMR 8523, Villeneuve d'Ascq, 59655, France.
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129
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Busanello FH, Petridis X, So MVR, Dijkstra RJB, Sharma PK, van der Sluis LWM. Chemical biofilm removal capacity of endodontic irrigants as a function of biofilm structure: optical coherence tomography, confocal microscopy and viscoelasticity determination as integrated assessment tools. Int Endod J 2018; 52:461-474. [DOI: 10.1111/iej.13027] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/03/2018] [Indexed: 12/14/2022]
Affiliation(s)
- F. H. Busanello
- Conservative Dentistry Department; School of Dentistry; Federal University of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
| | - X. Petridis
- Department of Conservative Dentistry; Center for Dentistry and Oral Hygiene; Groningen The Netherlands
| | - M. V. R. So
- Conservative Dentistry Department; School of Dentistry; Federal University of Rio Grande do Sul; Porto Alegre Rio Grande do Sul Brazil
| | - R. J. B. Dijkstra
- Department of Conservative Dentistry; Center for Dentistry and Oral Hygiene; Groningen The Netherlands
| | - P. K. Sharma
- Department of Biomedical Engineering; University Medical Center Groningen; University of Groningen; Groningen The Netherlands
| | - L. W. M. van der Sluis
- Department of Conservative Dentistry; Center for Dentistry and Oral Hygiene; Groningen The Netherlands
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130
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Seo Y, Leong J, Park JD, Hong YT, Chu SH, Park C, Kim DH, Deng YH, Dushnov V, Soh J, Rogers S, Yang YY, Kong H. Diatom Microbubbler for Active Biofilm Removal in Confined Spaces. ACS APPLIED MATERIALS & INTERFACES 2018; 10:35685-35692. [PMID: 30107112 PMCID: PMC8216637 DOI: 10.1021/acsami.8b08643] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bacterial biofilms form on and within many living tissues, medical devices, and engineered materials, threatening human health and sustainability. Removing biofilms remains a grand challenge despite tremendous efforts made so far, particularly when they are formed in confined spaces. One primary cause is the limited transport of antibacterial agents into extracellular polymeric substances (EPS) of the biofilm. In this study, we hypothesized that a microparticle engineered to be self-locomotive with microbubbles would clean a structure fouled by biofilm by fracturing the EPS and subsequently improving transports of the antiseptic reagent. We examined this hypothesis by doping a hollow cylinder-shaped diatom biosilica with manganese oxide (MnO2) nanosheets. In an antiseptic H2O2 solution, the diatoms doped by MnO2 nanosheets, denoted as diatom bubbler, discharged oxygen gas bubbles continuously and became self-motile. Subsequently, the diatoms infiltrated the bacterial biofilm formed on either flat or microgrooved silicon substrates and continued to generate microbubbles. The resulting microbubbles merged and converted surface energy to mechanical energy high enough to fracture the matrix of biofilm. Consequently, H2O2 molecules diffused into the biofilm and killed most bacterial cells. Overall, this study provides a unique and powerful tool that can significantly impact current efforts to clean a wide array of biofouled products and devices.
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Affiliation(s)
- Yongbeom Seo
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jiayu Leong
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore
| | - Jun Dong Park
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yu-Tong Hong
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Sang-Hyon Chu
- National Institute of Aerospace, 100 Exploration Way, Hampton, Virginia 23666, United States
| | - Cheol Park
- Advanced Materials and Processing Branch, NASA Langley Research Center, Hampton, Virginia 23681, United States
| | - Dong Hyun Kim
- Department of Human and Culture Convergence Technology R&BD Group, Korea Institute of Industrial Technology, Ansan-si, Gyeonggi-do 426-910, South Korea
| | - Yu-Heng Deng
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Vitaliy Dushnov
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Joonghui Soh
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Simon Rogers
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yi Yan Yang
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore
| | - Hyunjoon Kong
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carle Illinois College of Medicine, Department of Bioengineering, Department of Pathobiology, Carl R. Woese Institute for Genomic Biology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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131
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Characterization of a novel regulatory pathway for mannitol metabolism and its coordination with biofilm formation in Mycobacterium smegmatis. J Genet Genomics 2018; 45:477-488. [DOI: 10.1016/j.jgg.2018.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 06/26/2018] [Indexed: 01/03/2023]
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132
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Towards standardized mechanical characterization of microbial biofilms: analysis and critical review. NPJ Biofilms Microbiomes 2018; 4:17. [PMID: 30131867 PMCID: PMC6102240 DOI: 10.1038/s41522-018-0062-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 02/05/2023] Open
Abstract
Developing reliable anti-biofilm strategies or efficient biofilm-based bioprocesses strongly depends on having a clear understanding of the mechanisms underlying biofilm development, and knowledge of the relevant mechanical parameters describing microbial biofilm behavior. Many varied mechanical testing methods are available to assess these parameters. The mechanical properties thus identified can then be used to compare protocols such as antibiotic screening. However, the lack of standardization in both mechanical testing and the associated identification methods for a given microbiological goal remains a blind spot in the biofilm community. The pursuit of standardization is problematic, as biofilms are living structures, i.e., both complex and dynamic. Here, we review the main available methods for characterizing the mechanical properties of biofilms through the lens of the relationship linking experimental testing to the identification of mechanical parameters. We propose guidelines for characterizing biofilms according to microbiological objectives that will help the reader choose an appropriate test and a relevant identification method for measuring any given mechanical parameter. The use of a common methodology for the mechanical characterization of biofilms will enable reliable analysis and comparison of microbiological protocols needed for improvement of engineering process and screening.
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133
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Transmission of Monospecies and Dual-Species Biofilms from Smooth to Nanopillared Surfaces. Appl Environ Microbiol 2018; 84:AEM.01035-18. [PMID: 29802194 DOI: 10.1128/aem.01035-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 05/22/2018] [Indexed: 11/20/2022] Open
Abstract
The transmission of bacteria in biofilms from donor to receiver surfaces precedes the formation of biofilms in many applications. Biofilm transmission is different from bacterial adhesion, because it involves biofilm compression in between two surfaces, followed by a separation force leading to the detachment of the biofilm from the donor surface and subsequent adhesion to the receiver surface. Therewith, the transmission depends on a balance between donor and receiver surface properties and the cohesiveness of the biofilm itself. Here, we compare bacterial transmission from biofilms of an extracellular-polymeric-substance (EPS)-producing and a non-EPS-producing staphylococcal strain and a dual-species oral biofilm from smooth silicon (Si) donor surfaces to smooth and nanopillared Si receiver surfaces. Biofilms were fully covering the donor surface before transmission. However, after transmission, the biofilms only partly covered the donor and receiver surfaces regardless of nanopillaring, indicating bacterial transmission through adhesive failure at the interface between biofilms and donor surfaces as well as through cohesive failure in the biofilms. The numbers of bacteria per unit volume in EPS-producing staphylococcal biofilms before transmission were 2-fold smaller than in biofilms of the non-EPS-producing strain and of dual species. This difference increased after transmission in the biofilm left behind on the donor surfaces due to an increased bacterial density for the non-EPS-producing strain and a dual-species biofilm. This suggests that biofilms of the non-EPS-producing strain and dual species remained compressed after transmission, while biofilms of the EPS-producing strain were induced to produce more EPS during transmission and relaxed toward their initial state after transmission due to the viscoelasticity conferred to the biofilm by its EPS.IMPORTANCE Bacterial transmission from biofilm-covered surfaces to surfaces is mechanistically different from bacterial adhesion to surfaces and involves detachment from the donor and adhesion to the receiver surfaces under pressure. Bacterial transmission occurs, for instance, in food processing or packaging, in household situations, or between surfaces in hospitals. Patients admitted to a hospital room previously occupied by a patient with antibiotic-resistant pathogens are at elevated infection risk by the same pathogens through transmission. Nanopillared receiver surfaces did not collect less biofilm from a smooth donor than a smooth receiver, likely because the pressure applied during transmission negated the smaller contact area between bacteria and nanopillared surfaces, generally held responsible for reduced adhesion. Biofilm left behind on smooth donor surfaces of a non-extracellular-polymeric-substance (EPS)-producing strain and dual species had undergone different structural changes than an EPS-producing strain, which is important for their possible further treatment by antimicrobials or disinfectants.
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134
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Bakshani CR, Morales-Garcia AL, Althaus M, Wilcox MD, Pearson JP, Bythell JC, Burgess JG. Evolutionary conservation of the antimicrobial function of mucus: a first defence against infection. NPJ Biofilms Microbiomes 2018; 4:14. [PMID: 30002868 PMCID: PMC6031612 DOI: 10.1038/s41522-018-0057-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/05/2018] [Accepted: 06/06/2018] [Indexed: 02/07/2023] Open
Abstract
Mucus layers often provide a unique and multi-functional hydrogel interface between the epithelial cells of organisms and their external environment. Mucus has exceptional properties including elasticity, changeable rheology and an ability to self-repair by re-annealing, and is therefore an ideal medium for trapping and immobilising pathogens and serving as a barrier to microbial infection. The ability to produce a functional surface mucosa was an important evolutionary step, which evolved first in the Cnidaria, which includes corals, and the Ctenophora. This allowed the exclusion of non-commensal microbes and the subsequent development of the mucus-lined digestive cavity seen in higher metazoans. The fundamental architecture of the constituent glycoprotein mucins is also evolutionarily conserved. Although an understanding of the biochemical interactions between bacteria and the mucus layer are important to the goal of developing new antimicrobial strategies, they remain relatively poorly understood. This review summarises the physicochemical properties and evolutionary importance of mucus, which make it so successful in the prevention of bacterial infection. In addition, the strategies developed by bacteria to counteract the mucus layer are also explored.
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Affiliation(s)
- Cassie R Bakshani
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ana L Morales-Garcia
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Mike Althaus
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew D Wilcox
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Jeffrey P Pearson
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - John C Bythell
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - J Grant Burgess
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
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135
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Modelling the Nanomechanical Responses of Biofilms Grown on the Indenter Probe. Processes (Basel) 2018. [DOI: 10.3390/pr6070084] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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136
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Gloag ES, German GK, Stoodley P, Wozniak DJ. Viscoelastic properties of Pseudomonas aeruginosa variant biofilms. Sci Rep 2018; 8:9691. [PMID: 29946126 PMCID: PMC6018706 DOI: 10.1038/s41598-018-28009-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/05/2018] [Indexed: 01/11/2023] Open
Abstract
Pseudomonas aeruginosa evolves during chronic pulmonary infections of cystic fibrosis (CF) patients, forming pathoadapted variants that are persistent. Mucoid and rugose small-colony variants (RSCVs) are typically isolated from sputum of CF patients. These variants overproduce exopolysaccharides in the biofilm extracellular polymeric substance (EPS). Currently, changes to the biophysical properties of RSCV and mucoid biofilms due to variations in EPS are not well understood. This knowledge may reveal how lung infections resist host clearance mechanisms. Here, we used mechanical indentation and shear rheometry to analyse the viscoelasticity of RSCV and mucoid colony-biofilms compared to their isogenic parent at 2-, 4-, and 6-d. While the viscoelasticity of parental colony-biofilms underwent fluctuating temporal changes, in contrast, RSCV and mucoid colony-biofilms showed a gradual progression to more elastic-solid behaviour. Theoretical indices of mucociliary and cough clearance predict that mature 6-d parental and RSCV biofilms may show reduced cough clearance from the lung, while early mucoid biofilms may show reduced clearance by both mechanisms. We propose that viscoelasticity be considered a virulence property of biofilms.
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Affiliation(s)
- Erin S Gloag
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Guy K German
- Department of Biomedical Engineering, Binghamton University, Binghamton, NY, 13902, USA
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, OH, 43210, USA. .,Department of Orthopedics, The Ohio State University, Columbus, OH, 43210, USA. .,National Centre for Advanced Tribology at Southampton, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, OH, 43210, USA
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137
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Treatment of Biofilm Communities: An Update on New Tools from the Nanosized World. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8060845] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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138
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Huang H, Lin Y, Peng P, Geng J, Xu K, Zhang Y, Ding L, Ren H. Calcium ion- and rhamnolipid-mediated deposition of soluble matters on biocarriers. WATER RESEARCH 2018; 133:37-46. [PMID: 29407713 DOI: 10.1016/j.watres.2018.01.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/28/2017] [Accepted: 01/04/2018] [Indexed: 06/07/2023]
Abstract
Start-up of biofilm process initiated by the deposition of soluble matters on biocarriers is a very important yet time-consuming procedure. However, rapid start-up methods especially in the enhancement of soluble matters deposition have been rarely addressed. In this study, a quartz crystal microbalance with dissipation monitoring (QCM-D) was applied to investigate the influences of calcium ion and rhamnolipid (RL) on the deposition of soluble matters from real and synthetic industrial wastewaters with different configurations of organics (bovine serum albumin and sodium alginate) and ionic strength on the model biocarriers polystyrene and polyamide. Results showed that deposition was effectively promoted by the addition of Ca2+ and along with the increase in Ca2+ content. However, RL enhanced the deposition effectively only in hyperhaline wastewater through breaking hydration repulsion and decreased the deposition in low-salinity wastewater, and its influence to the deposited layer property exhibited characteristics of negative feedback. The combined use of Ca2+ and RL had a better enhancement effect than that of separate use and the mechanism involved can not be soundly explained only by Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The strategy of mediating the deposition of soluble matters on different biocarriers by adding Ca2+ and RL has important implications for regulating biofilm formation to accelerate the start-up process in attached-growth bioreactors.
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Affiliation(s)
- Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yuan Lin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Pengcheng Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Jinju Geng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ke Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Lili Ding
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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139
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Bowen WH, Burne RA, Wu H, Koo H. Oral Biofilms: Pathogens, Matrix, and Polymicrobial Interactions in Microenvironments. Trends Microbiol 2018; 26:229-242. [PMID: 29097091 PMCID: PMC5834367 DOI: 10.1016/j.tim.2017.09.008] [Citation(s) in RCA: 518] [Impact Index Per Article: 86.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 08/26/2017] [Accepted: 09/25/2017] [Indexed: 02/07/2023]
Abstract
Biofilms are microbial communities embedded within an extracellular matrix, forming a highly organized structure that causes many human infections. Dental caries (tooth decay) is a polymicrobial biofilm disease driven by the diet and microbiota-matrix interactions that occur on a solid surface. Sugars fuel the emergence of pathogens, the assembly of the matrix, and the acidification of the biofilm microenvironment, promoting ecological changes and concerted multispecies efforts that are conducive to acid damage of the mineralized tooth tissue. Here, we discuss recent advances in the role of the biofilm matrix and interactions between opportunistic pathogens and commensals in the pathogenesis of dental caries. In addition, we highlight the importance of matrix-producing organisms in fostering a pathogenic habitat where interspecies competition and synergies occur to drive the disease process, which could have implications to other infections associated with polymicrobial biofilms.
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Affiliation(s)
- William H Bowen
- Center for Oral Biology, Department of Microbiology & Immunology and Environmental Medicine, University of Rochester Medical Center, Rochester, New York, NY, USA; Deceased (15 November 2016)
| | - Robert A Burne
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Hui Wu
- Departments of Microbiology and Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hyun Koo
- Levy Center for Oral Health, Department of Orthodontics, Divisions of Pediatric Dentistry and Community of Oral Health, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA.
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140
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Cao Y, Su B, Chinnaraj S, Jana S, Bowen L, Charlton S, Duan P, Jakubovics NS, Chen J. Nanostructured titanium surfaces exhibit recalcitrance towards Staphylococcus epidermidis biofilm formation. Sci Rep 2018; 8:1071. [PMID: 29348582 PMCID: PMC5773551 DOI: 10.1038/s41598-018-19484-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 12/27/2017] [Indexed: 11/08/2022] Open
Abstract
Titanium-based implants are ubiquitous in the healthcare industries and often suffer from bacterial attachment which results in infections. An innovative method of reducing bacterial growth is to employ nanostructures on implant materials that cause contact-dependent cell death by mechanical rupture of bacterial cell membranes. To achieve this, we synthesized nanostructures with different architectures on titanium surfaces using hydrothermal treatment processes and then examined the growth of Staphylococcus epidermidis on these surfaces. The structure obtained after a two-hour hydrothermal treatment (referred to as spear-type) showed the least bacterial attachment at short times but over a period of 6 days tended to support the formation of thick biofilms. By contrast, the structure obtained after a three-hour hydrothermal treatment (referred to as pocket-type) was found to delay biofilm formation up to 6 days and killed 47% of the initially attached bacteria by penetrating or compressing the bacteria in between the network of intertwined nano-spears. The results point to the efficacy of pocket-type nanostructure in increasing the killing rate of individual bacteria and potentially delaying longer-term biofilm formation.
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Affiliation(s)
- Yunyi Cao
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK
| | - Bo Su
- School of Oral and Dental Sciences, University of Bristol, Bristol, BS1 2LY, UK
| | - Subash Chinnaraj
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK
| | - Saikat Jana
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK
| | - Leon Bowen
- Department of Physics, Durham University, Durham, DH1 3LE, UK
| | - Sam Charlton
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK
| | - Pengfei Duan
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK
| | | | - Jinju Chen
- School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
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141
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Hou J, Veeregowda DH, van de Belt-Gritter B, Busscher HJ, van der Mei HC. Extracellular Polymeric Matrix Production and Relaxation under Fluid Shear and Mechanical Pressure in Staphylococcus aureus Biofilms. Appl Environ Microbiol 2018; 84:e01516-17. [PMID: 29054874 PMCID: PMC5734043 DOI: 10.1128/aem.01516-17] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/11/2017] [Indexed: 12/20/2022] Open
Abstract
The viscoelasticity of a biofilm's EPS (extracellular polymeric substance) matrix conveys protection against mechanical challenges, but adaptive responses of biofilm inhabitants to produce EPS are not well known. Here, we compare the responses of a biofilm of an EPS-producing (ATCC 12600) and a non-EPS producing (5298) Staphylococcus aureus strain to fluid shear and mechanical challenge. Confocal laser scanning microscopy confirmed absence of calcofluor-white-stainable EPS in biofilms of S. aureus 5298. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy combined with tribometry indicated that polysaccharide production per bacterium in the initial adhering layer was higher during growth at high shear than at low shear and that this increased EPS production extended to entire biofilms, as indicated by tribometrically measured coefficients of friction (CoF). CoF of biofilms grown under high fluid shear were higher than those when grown under low shear, likely due to wash-off polysaccharides. Measurement of a biofilm's CoF implies application of mechanical pressure that yielded an immediate increase in the polysaccharide band area of S. aureus ATCC 12600 biofilms due to their compression. Compression decreased after relief of pressure to the level observed prior to mechanical pressure. For biofilms grown under high shear, this coincided with a higher percent whiteness in optical coherence tomography-images indicative of water outflow, returning back into the biofilm during stress relaxation. Biofilms grown under low shear, however, were stimulated during tribometry to produce EPS, also after relief of stress. Knowledge of factors that govern EPS production and water flow in biofilms will allow better control of biofilms under mechanical challenge and better understanding of the barrier properties of biofilms against antimicrobial penetration.IMPORTANCE Adaptive responses of biofilm inhabitants in nature to environmental challenges such as fluid shear and mechanical pressure often involve EPS production with the aim of protecting biofilm inhabitants. EPS can assist biofilm bacteria in remaining attached or can impede antimicrobial penetration. The TriboChemist is a recently introduced instrument, allowing the study of initially adhering bacteria to a germanium crystal using ATR-FTIR spectroscopy, while simultaneously allowing measurement of the coefficient of friction of a biofilm, which serves as an indicator of the EPS content of a biofilm. EPS production can be stimulated by both fluid shear during growth and mechanical pressure, while increased EPS production can continue after pressure relaxation of the biofilm. Since EPS is pivotal in the protection of biofilm inhabitants against mechanical and chemical challenges, knowledge of the factors that make biofilm inhabitants decide to produce EPS, as provided in this study, is important for the development of biofilm control measures.
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Affiliation(s)
- Jiapeng Hou
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Groningen, The Netherlands
| | - Deepak H Veeregowda
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Groningen, The Netherlands
- Ducom Instruments Europe BV, Center for Innovation, Groningen, The Netherlands
| | - Betsy van de Belt-Gritter
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Groningen, The Netherlands
| | - Henk J Busscher
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Groningen, The Netherlands
| | - Henny C van der Mei
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Groningen, The Netherlands
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142
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Tarifa MC, Genovese D, Lozano JE, Brugnoni LI. In situ microstructure and rheological behavior of yeast biofilms from the juice processing industries. BIOFOULING 2018; 34:74-85. [PMID: 29228797 DOI: 10.1080/08927014.2017.1407758] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
The factors affecting the mechanical properties of biofilms formed by yeast species (Rhodotorula mucilaginosa, Candida krusei, C. kefyr and C. tropicalis) isolated from the juice processing industries have been investigated. Variables studied were: the food matrix (apple/pear juice), the sugar concentration (6/12 °Bx) and the hydrodynamic conditions (static/turbulent flow). A range of environmental cues were included as the mechanical properties of biofilms are complex. Yeast counts were significantly higher in turbulent flow compared with under static conditions. The thickness of the biofilm ranged from 38 to 148 μm, from static to turbulent flow. Yeast biofilms grown under turbulent flow conditions were viscoelastic with a predominant solid-like behavior and were structurally stronger than those grown under static conditions, indicating gel-type structures. Only the type of flow had a significant effect on [Formula: see text] and G*. Flow velocity and nutrient status modulated the biofilm thickness, the biomass and the mechanical properties. A better knowledge of the factors controlling biofilm formation will help in the development of control strategies.
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Affiliation(s)
- María C Tarifa
- a Institute of Biological and Biomedical Sciences of the South INBIOSUR) , Universidad Nacional del Sur (UNS), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Bahía Blanca , Argentina
| | - Diego Genovese
- b Pilot Plant of Chemical Engineering (PLAPIQUI) , Universidad Nacional del Sur (UNS), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Bahía Blanca , Argentina
| | - Jorge E Lozano
- b Pilot Plant of Chemical Engineering (PLAPIQUI) , Universidad Nacional del Sur (UNS), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Bahía Blanca , Argentina
| | - Lorena I Brugnoni
- a Institute of Biological and Biomedical Sciences of the South INBIOSUR) , Universidad Nacional del Sur (UNS), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Bahía Blanca , Argentina
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143
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Pandit S, Ravikumar V, Abdel-Haleem AM, Derouiche A, Mokkapati VRSS, Sihlbom C, Mineta K, Gojobori T, Gao X, Westerlund F, Mijakovic I. Low Concentrations of Vitamin C Reduce the Synthesis of Extracellular Polymers and Destabilize Bacterial Biofilms. Front Microbiol 2017; 8:2599. [PMID: 29317857 PMCID: PMC5748153 DOI: 10.3389/fmicb.2017.02599] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 12/13/2017] [Indexed: 11/13/2022] Open
Abstract
Extracellular polymeric substances (EPS) produced by bacteria form a matrix supporting the complex three-dimensional architecture of biofilms. This EPS matrix is primarily composed of polysaccharides, proteins and extracellular DNA. In addition to supporting the community structure, the EPS matrix protects bacterial biofilms from the environment. Specifically, it shields the bacterial cells inside the biofilm, by preventing antimicrobial agents from getting in contact with them, thereby reducing their killing effect. New strategies for disrupting the formation of the EPS matrix can therefore lead to a more efficient use of existing antimicrobials. Here we examined the mechanism of the known effect of vitamin C (sodium ascorbate) on enhancing the activity of various antibacterial agents. Our quantitative proteomics analysis shows that non-lethal concentrations of vitamin C inhibit bacterial quorum sensing and other regulatory mechanisms underpinning biofilm development. As a result, the EPS biosynthesis in reduced, and especially the polysaccharide component of the matrix is depleted. Once the EPS content is reduced beyond a critical point, bacterial cells get fully exposed to the medium. At this stage, the cells are more susceptible to killing, either by vitamin C-induced oxidative stress as reported here, or by other antimicrobials or treatments.
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Affiliation(s)
- Santosh Pandit
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Vaishnavi Ravikumar
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Alyaa M Abdel-Haleem
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Abderahmane Derouiche
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - V R S S Mokkapati
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Carina Sihlbom
- Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Katsuhiko Mineta
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Takashi Gojobori
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Xin Gao
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Fredrik Westerlund
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Ivan Mijakovic
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
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144
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Bas S, Kramer M, Stopar D. Biofilm Surface Density Determines Biocide Effectiveness. Front Microbiol 2017; 8:2443. [PMID: 29276508 PMCID: PMC5727120 DOI: 10.3389/fmicb.2017.02443] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 11/24/2017] [Indexed: 12/28/2022] Open
Abstract
High resistance of biofilms for chemical challenges is a serious industrial and medical problem. In this work a gradient of surface covered with biofilm has been produced and correlated to the effectiveness of different commercially available oxidative biocides. The results for thin Escherichia coli biofilms grown in rich media supplemented with glucose or lactose on glass or poly methyl methacrylate surfaces indicate that the effectiveness of hydrogen peroxide or chlorine dioxide and quaternary ammonium compounds is inversely proportional to the fraction of the surface covered with the biofilm. In areas where biofilm covered more than 90% of the available surface the biocide treatment was inefficient after 60 min of incubation. The combined effect of oxidant and surfactant increased the effectiveness of the biocide. On the other hand, the increased biofilm viscoelasticity reduced biocide effectiveness. The results emphasize differential biocide effectiveness depending on the fraction of the attached bacterial cells. The results suggest that biofilm biocide resistance is an acquired property that increases with biofilm maturation. The more dense sessile structures present lower log reductions compared to less dense ones.
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Affiliation(s)
- Sara Bas
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | | | - David Stopar
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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145
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Koo H, Allan RN, Howlin RP, Hall-Stoodley L, Stoodley P. Targeting microbial biofilms: current and prospective therapeutic strategies. Nat Rev Microbiol 2017; 15:740-755. [PMID: 28944770 PMCID: PMC5685531 DOI: 10.1038/nrmicro.2017.99] [Citation(s) in RCA: 978] [Impact Index Per Article: 139.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Biofilm formation is a key virulence factor for a wide range of microorganisms that cause chronic infections. The multifactorial nature of biofilm development and drug tolerance imposes great challenges for the use of conventional antimicrobials and indicates the need for multi-targeted or combinatorial therapies. In this Review, we focus on current therapeutic strategies and those under development that target vital structural and functional traits of microbial biofilms and drug tolerance mechanisms, including the extracellular matrix and dormant cells. We emphasize strategies that are supported by in vivo or ex vivo studies, highlight emerging biofilm-targeting technologies and provide a rationale for multi-targeted therapies aimed at disrupting the complex biofilm microenvironment.
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Affiliation(s)
- Hyun Koo
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, PA, USA
| | - Raymond N Allan
- Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Robert P Howlin
- Centre for Biological Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Luanne Hall-Stoodley
- Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK
- Department of Microbial Infection and Immunity, Centre for Microbial Interface Biology, The Ohio State University, Columbus, Ohio, USA
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, Centre for Microbial Interface Biology, The Ohio State University, Columbus, Ohio, USA
- Depts. Orthopaedics and Microbiology, The Ohio State University, Columbus, Ohio, USA
- National Center for Advanced Tribology at Southampton (nCATS), Faculty of Engineering and the Environment, University of Southampton, UK
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146
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Zhang R, Xia A, Ni L, Li F, Jin Z, Yang S, Jin F. Strong Shear Flow Persister Bacteria Resist Mechanical Washings on the Surfaces of Various Polymer Materials. ACTA ACUST UNITED AC 2017; 1:e1700161. [PMID: 32646157 DOI: 10.1002/adbi.201700161] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 09/21/2017] [Indexed: 11/10/2022]
Abstract
Environmental bacteria persistently exist in hospitals and thereby often contaminate biomedical devices, which usually causes device-associated infections that have become a major cause of patient illness and death in the hospital. In this study, for the first time, the identification of strong shear flow persister (SSP) cells in Pseudomonas aeruginosa is reported. Unlike common persister cells that are highly tolerant to antibiotics, it is reported that the SSP cells can resist mechanical washings on the surfaces of various polymer materials and can form distinctive biofilms that are tolerant to high doses of aminoglycoside antibiotics. Most importantly, a general molecular mechanism is revealed by which an outer membrane protein crosslinks with polysaccharides to form gel-like adhesion complexes that can exert extremely strong adhesion strength (up to 50 N mm-2 ). Therefore, these findings are urgently required for ongoing research focused on preparing antifouling biomedical materials.
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Affiliation(s)
- Rongrong Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Aiguo Xia
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Lei Ni
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Feixuan Li
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Zhenyu Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Shuai Yang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Fan Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
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147
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Ma TM, VanEpps JS, Solomon MJ. Structure, Mechanics, and Instability of Fibrin Clot Infected with Staphylococcus epidermidis. Biophys J 2017; 113:2100-2109. [PMID: 29117532 DOI: 10.1016/j.bpj.2017.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/20/2017] [Accepted: 09/01/2017] [Indexed: 11/19/2022] Open
Abstract
Health care-associated infection, over half of which can be attributed to indwelling medical devices, is a strong risk factor for thromboembolism. Although most experimental models of medical device infection draw upon isolated bacterial biofilms, in fact there is no infection without host protein contribution. Here we study, to our knowledge, a new model for medical device infection-that of an infected fibrin clot-and show that the common blood-borne pathogen Staphylococcus epidermidis influences this in vitro model of a blood clot mechanically and structurally on both microscopic and macroscopic scales. Bacteria present during clot formation produce a visibly disorganized microstructure that increases clot stiffness and triggers mechanical instability over time. Our results provide insight into the observed correlation between medical device infection and thromboembolism; the increase in model clot heterogeneity shows that S. epidermidis can rupture a fibrin clot. The resultant embolization of the infected clot can contribute to the systemic dissemination of the pathogen.
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Affiliation(s)
- Tianhui Maria Ma
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan
| | - J Scott VanEpps
- Department of Emergency Medicine, Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan; Department of Biomedical Engineering, Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan.
| | - Michael J Solomon
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan; Department of Biomedical Engineering, Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan.
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148
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Romero CM, Martorell PV, López AG, Peñalver CGN, Chaves S, Mechetti M. Architecture and physicochemical characterization of Bacillus biofilm as a potential enzyme immobilization factory. Colloids Surf B Biointerfaces 2017; 162:246-255. [PMID: 29216511 DOI: 10.1016/j.colsurfb.2017.11.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/09/2017] [Accepted: 11/22/2017] [Indexed: 11/18/2022]
Abstract
Biocatalysis for industrial application is based on the use of enzymes to perform complex transformations. However, these systems have some disadvantage related to the costs of the biocatalyst. In this work, an alternative strategy for producing green immobilized biocatalysts based on biofilm was developed.A study of the rheological behavior of the biofilm from Bacillus sp. Mcn4, as well as the determination of its composition, was carried out. The dynamic rheological measurements, viscosity (G") and elasticity (G') module, showed that the biofilm presents appreciable elastic components, which is a recognized property for enzymes immobilization. After the partial purification, the exopolysaccharidewas identified as a levan with a non-Newtonian behavior. Extracellular DNA with fragments between 10,000 and 1000bp was detected also in the biofilm, and amyloid protein in the extracellular matrix using a fluorescence technique was identified. Bacillus sp. Mcn4 biofilms were developed on different surfaces, being the most stable those developed on hydrophilic supports. The biofilm showed lipase activity suggesting the presence of constitutive lipases entrapped into the biofilm. Indeed, two enzymes with lipase activity were identified in native PAGE. These were used as biocatalysts, whose reuse showed a residual lipase activity after more than one cycle of catalysis. The components identified in the biofilm could be the main contributors of the rheological characteristic of this material, giving an exceptional environment to the lipase enzyme. Based on these findings, the current study proposes green and natural biopolymers matrix as support for the enzyme immobilization for industrial applications.
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Affiliation(s)
- C M Romero
- PROIMI, PROIMI-CONICET, Av. Belgrano y Pasaje Caseros, T4001 MVB, Tucumán Fac. Bioq., Qca. y Farmacia (UNT), Ayacucho 471, 4000, Tucumán, Argentina.
| | - P V Martorell
- PROIMI, PROIMI-CONICET, Av. Belgrano y Pasaje Caseros, T4001 MVB, Tucumán Fac. Bioq., Qca. y Farmacia (UNT), Ayacucho 471, 4000, Tucumán, Argentina
| | - A Gómez López
- Laboratorio de Física de Fluidos y Electrorreología, Instituto de Física del Noroeste Argentino-INFINOA (CONICET-UNT), Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, Av. Independencia 1800, San Miguel de Tucumán, 4000, Argentina
| | - C G Nieto Peñalver
- PROIMI, PROIMI-CONICET, Av. Belgrano y Pasaje Caseros, T4001 MVB, Tucumán Fac. Bioq., Qca. y Farmacia (UNT), Ayacucho 471, 4000, Tucumán, Argentina
| | - S Chaves
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT. Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina
| | - M Mechetti
- Laboratorio de Física de Fluidos y Electrorreología, Instituto de Física del Noroeste Argentino-INFINOA (CONICET-UNT), Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, Av. Independencia 1800, San Miguel de Tucumán, 4000, Argentina
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149
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Hwang G, Koltisko B, Jin X, Koo H. Nonleachable Imidazolium-Incorporated Composite for Disruption of Bacterial Clustering, Exopolysaccharide-Matrix Assembly, and Enhanced Biofilm Removal. ACS APPLIED MATERIALS & INTERFACES 2017; 9:38270-38280. [PMID: 29020439 DOI: 10.1021/acsami.7b11558] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Surface-grown bacteria and production of an extracellular polymeric matrix modulate the assembly of highly cohesive and firmly attached biofilms, making them difficult to remove from solid surfaces. Inhibition of cell growth and inactivation of matrix-producing bacteria can impair biofilm formation and facilitate removal. Here, we developed a novel nonleachable antibacterial composite with potent antibiofilm activity by directly incorporating polymerizable imidazolium-containing resin (antibacterial resin with carbonate linkage; ABR-C) into a methacrylate-based scaffold (ABR-modified composite; ABR-MC) using an efficient yet simplified chemistry. Low-dose inclusion of imidazolium moiety (∼2 wt %) resulted in bioactivity with minimal cytotoxicity without compromising mechanical integrity of the restorative material. The antibiofilm properties of ABR-MC were assessed using an exopolysaccharide-matrix-producing (EPS-matrix-producing) oral pathogen (Streptococcus mutans) in an experimental biofilm model. Using high-resolution confocal fluorescence imaging and biophysical methods, we observed remarkable disruption of bacterial accumulation and defective 3D matrix structure on the surface of ABR-MC. Specifically, the antibacterial composite impaired the ability of S. mutans to form organized bacterial clusters on the surface, resulting in altered biofilm architecture with sparse cell accumulation and reduced amounts of EPS matrix (versus control composite). Biofilm topology analyses on the control composite revealed a highly organized and weblike EPS structure that tethers the bacterial clusters to each other and to the surface, forming a highly cohesive unit. In contrast, such a structured matrix was absent on the surface of ABR-MC with mostly sparse and amorphous EPS, indicating disruption in the biofilm physical stability. Consistent with lack of structural organization, the defective biofilm on the surface of ABR-MC was readily detached when subjected to low shear stress, while most of the biofilm biomass remained on the control surface. Altogether, we demonstrate a new nonleachable antibacterial composite with excellent antibiofilm activity without affecting its mechanical properties, which may serve as a platform for development of alternative antifouling biomaterials.
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Affiliation(s)
- Geelsu Hwang
- Biofilm Research Laboratories, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania , 240 South 40th Street, Levy Building Room 417, Philadelphia, Pennsylvania 19104, United States
| | - Bernard Koltisko
- Dentsply Sirona , 38 West Clarke Avenue, Milford, Delaware 19963, United States
| | - Xiaoming Jin
- Dentsply Sirona , 38 West Clarke Avenue, Milford, Delaware 19963, United States
| | - Hyun Koo
- Biofilm Research Laboratories, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania , 240 South 40th Street, Levy Building Room 417, Philadelphia, Pennsylvania 19104, United States
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150
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Gusnaniar N, Sjollema J, Nuryastuti T, Peterson BW, van de Belt-Gritter B, de Jong ED, van der Mei HC, Busscher HJ. Structural changes in S. epidermidis biofilms after transmission between stainless steel surfaces. BIOFOULING 2017; 33:712-721. [PMID: 28868925 DOI: 10.1080/08927014.2017.1360870] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 07/25/2017] [Indexed: 06/07/2023]
Abstract
Transmission is a main route for bacterial contamination, involving bacterial detachment from a donor and adhesion to receiver surfaces. This work aimed to compare transmission of an extracellular polymeric substance (EPS) producing and a non-EPS producing Staphylococcus epidermidis strain from biofilms on stainless steel. After transmission, donor surfaces remained fully covered with biofilm, indicating transmission through cohesive failure in the biofilm. Counter to the numbers of biofilm bacteria, the donor and receiver biofilm thicknesses did not add up to the pre-transmission donor biofilm thickness, suggesting more compact biofilms after transmission, especially for non-EPS producing staphylococci. Accordingly, staphylococcal density per unit biofilm volume had increased from 0.20 to 0.52 μm-3 for transmission of the non-EPS producing strain under high contact pressure. The EPS producing strain had similar densities before and after transmission (0.17 μm-3). This suggests three phases in biofilm transmission: (1) compression, (2) separation and (3) relaxation of biofilm structure to its pre-transmission density in EPS-rich biofilms.
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Affiliation(s)
- Niar Gusnaniar
- a Department of Biomedical Engineering , University of Groningen and University Medical Center Groningen , Groningen , the Netherlands
| | - Jelmer Sjollema
- a Department of Biomedical Engineering , University of Groningen and University Medical Center Groningen , Groningen , the Netherlands
| | - Titik Nuryastuti
- b Faculty of Medicine, Department of Microbiology , Universitas Gadjah Mada , Yogyakarta , Indonesia
| | - Brandon W Peterson
- a Department of Biomedical Engineering , University of Groningen and University Medical Center Groningen , Groningen , the Netherlands
| | - Betsy van de Belt-Gritter
- a Department of Biomedical Engineering , University of Groningen and University Medical Center Groningen , Groningen , the Netherlands
| | - Ed D de Jong
- a Department of Biomedical Engineering , University of Groningen and University Medical Center Groningen , Groningen , the Netherlands
| | - Henny C van der Mei
- a Department of Biomedical Engineering , University of Groningen and University Medical Center Groningen , Groningen , the Netherlands
| | - Henk J Busscher
- a Department of Biomedical Engineering , University of Groningen and University Medical Center Groningen , Groningen , the Netherlands
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