2751
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Maes S, Huu SN, Heyndrickx M, Weyenberg SV, Steenackers H, Verplaetse A, Vackier T, Sampers I, Raes K, Reu KD. Evaluation of Two Surface Sampling Methods for Microbiological and Chemical Analyses To Assess the Presence of Biofilms in Food Companies. J Food Prot 2017; 80:2022-2028. [PMID: 29140744 DOI: 10.4315/0362-028x.jfp-17-210] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Biofilms are an important source of contamination in food companies, yet the composition of biofilms in practice is still mostly unknown. The chemical and microbiological characterization of surface samples taken after cleaning and disinfection is very important to distinguish free-living bacteria from the attached bacteria in biofilms. In this study, sampling methods that are potentially useful for both chemical and microbiological analyses of surface samples were evaluated. In the manufacturing facilities of eight Belgian food companies, surfaces were sampled after cleaning and disinfection using two sampling methods: the scraper-flocked swab method and the sponge stick method. Microbiological and chemical analyses were performed on these samples to evaluate the suitability of the sampling methods for the quantification of extracellular polymeric substance components and microorganisms originating from biofilms in these facilities. The scraper-flocked swab method was most suitable for chemical analyses of the samples because the material in these swabs did not interfere with determination of the chemical components. For microbiological enumerations, the sponge stick method was slightly but not significantly more effective than the scraper-flocked swab method. In all but one of the facilities, at least 20% of the sampled surfaces had more than 102 CFU/100 cm2. Proteins were found in 20% of the chemically analyzed surface samples, and carbohydrates and uronic acids were found in 15 and 8% of the samples, respectively. When chemical and microbiological results were combined, 17% of the sampled surfaces were contaminated with both microorganisms and at least one of the analyzed chemical components; thus, these surfaces were characterized as carrying biofilm. Overall, microbiological contamination in the food industry is highly variable by food sector and even within a facility at various sampling points and sampling times.
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Affiliation(s)
- Sharon Maes
- 1 Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food, Brusselsesteenweg 370, 9090 Melle, Belgium
| | - Son Nguyen Huu
- 2 Department of Industrial Biological Sciences, Faculty of Bioscience Engineering, Ghent University-Kortrijk, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium
| | - Marc Heyndrickx
- 1 Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food, Brusselsesteenweg 370, 9090 Melle, Belgium.,3 Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Stephanie van Weyenberg
- 1 Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food, Brusselsesteenweg 370, 9090 Melle, Belgium
| | - Hans Steenackers
- 4 Centre of Microbial and Plant Genetics, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, University of Leuven, Kasteelpark Arenberg 20 Box 2460, 3001 Leuven, Belgium; and
| | - Alex Verplaetse
- 5 Laboratory of Enzyme, Fermentation and Brewery Technology, Cluster for Bioengineering Technology, Department of Microbial and Molecular Systems, Faculty of Engineering Technology, University of Leuven, Gebroeders De Smetstraat 1, 9000 Ghent, Belgium
| | - Thijs Vackier
- 5 Laboratory of Enzyme, Fermentation and Brewery Technology, Cluster for Bioengineering Technology, Department of Microbial and Molecular Systems, Faculty of Engineering Technology, University of Leuven, Gebroeders De Smetstraat 1, 9000 Ghent, Belgium
| | - Imca Sampers
- 2 Department of Industrial Biological Sciences, Faculty of Bioscience Engineering, Ghent University-Kortrijk, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium
| | - Katleen Raes
- 2 Department of Industrial Biological Sciences, Faculty of Bioscience Engineering, Ghent University-Kortrijk, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium
| | - Koen De Reu
- 1 Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food, Brusselsesteenweg 370, 9090 Melle, Belgium
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2752
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Moon SH, Zhang X, Zheng G, Meeker DG, Smeltzer MS, Huang E. Novel Linear Lipopeptide Paenipeptins with Potential for Eradicating Biofilms and Sensitizing Gram-Negative Bacteria to Rifampicin and Clarithromycin. J Med Chem 2017; 60:9630-9640. [PMID: 29136469 DOI: 10.1021/acs.jmedchem.7b01064] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We report the structure-activity relationship analyses of 17 linear lipopeptide paenipeptin analogues. Analogues 7, 12, and 17 were more potent than the lead compound. Analogue 17 was active against carbapenem-resistant and polymyxin-resistant pathogens. This compound at 40 μg/mL resulted in 3 log and 2.6 log reductions of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, respectively, in catheter-associated biofilms in vitro. Analogue 17 showed little hemolysis at 32 μg/mL and lysed 11% of red blood cells at 64 μg/mL. Analogues 9 and 16 were nonhemolytic and retained potent P. aeruginosa-specific antimicrobial activity. These two analogues when used alone lacked activity against Acinetobacter baumannii and Klebsiella pneumoniae; however, analogue 9 and 16 at 4 μg/mL decreased the MIC of rifampicin and clarithromycin against the same pathogens from 16 to 32 μg/mL to nanomolar levels (sensitization factor: 2048-8192). Therefore, paenipeptins, alone or in combination with rifampicin or clarithromycin, are promising candidates for treating bacterial infections.
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Affiliation(s)
- Sun Hee Moon
- Department of Environmental and Occupational Health, ‡Department of Pharmaceutical Sciences, §Department of Microbiology and Immunology, and ∥Department of Orthopedic Surgery, University of Arkansas for Medical Sciences , 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Xuan Zhang
- Department of Environmental and Occupational Health, ‡Department of Pharmaceutical Sciences, §Department of Microbiology and Immunology, and ∥Department of Orthopedic Surgery, University of Arkansas for Medical Sciences , 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Guangrong Zheng
- Department of Environmental and Occupational Health, ‡Department of Pharmaceutical Sciences, §Department of Microbiology and Immunology, and ∥Department of Orthopedic Surgery, University of Arkansas for Medical Sciences , 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Daniel G Meeker
- Department of Environmental and Occupational Health, ‡Department of Pharmaceutical Sciences, §Department of Microbiology and Immunology, and ∥Department of Orthopedic Surgery, University of Arkansas for Medical Sciences , 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - Mark S Smeltzer
- Department of Environmental and Occupational Health, ‡Department of Pharmaceutical Sciences, §Department of Microbiology and Immunology, and ∥Department of Orthopedic Surgery, University of Arkansas for Medical Sciences , 4301 West Markham Street, Little Rock, Arkansas 72205, United States
| | - En Huang
- Department of Environmental and Occupational Health, ‡Department of Pharmaceutical Sciences, §Department of Microbiology and Immunology, and ∥Department of Orthopedic Surgery, University of Arkansas for Medical Sciences , 4301 West Markham Street, Little Rock, Arkansas 72205, United States
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2753
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Zhang Y, Wang A, DeBenedictis EP, Keten S. Bending energy penalty enhances the adhesive strength of functional amyloid curli to surfaces. NANOTECHNOLOGY 2017; 28:464002. [PMID: 28952462 DOI: 10.1088/1361-6528/aa8f72] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The functional amyloid curli fiber, a major proteinaceous component of biofilm extracellular matrices, plays an important role in biofilm formation and enterobacteriaceae adhesion. Curli nanofibers exhibit exceptional underwater adhesion to various surfaces, have high rigidity and strong tensile mechanical properties, and thus hold great promise in biomaterials. The mechanisms of how curli fibers strongly attach to surfaces and detach under force remain elusive. To investigate curli fiber adhesion to surfaces, we developed a coarse-grained curli fiber model, in which the protein subunit CsgA (curli specific gene A) self-assembles into the fiber. The coarse-grained model yields physiologically relevant and tunable bending rigidity and persistence length. The force-induced desorption of a single curli fiber is examined using coarse-grained modeling and theoretical analysis. We find that the bending energy penalty arising from high persistence length enhances the resistance of the curli fiber against desorption and thus strengthens the adhesion of the curli fiber to surfaces. The CsgA-surface adhesion energy and the curli fiber bending rigidity both play crucial roles in the resistance of curli fiber against desorption from surfaces. To enable the desorption process, the applied peeling force must overcome both the interfacial adhesion energy and the energy barrier for bending the curli fiber at the peeling front. We show that the energy barrier to desorption increases with the interfacial adhesion energy, however, the bending induced failure of a single curli fiber limits the work of adhesion if the proportion of the CsgA-surface adhesion energy to the CsgA-CsgA cohesive energy becomes large. These results illustrate that the optimal adhesion performance of nanofibers is dictated by the interplay between bending, surface energy and cohesive energy. Our model provides timely insight into enterobacteriaceae adhesion mechanisms as well as future designs of engineered curli fiber based adhesives.
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Affiliation(s)
- Yao Zhang
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, United States of America
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2754
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Antimicrobial and Osseointegration Properties of Nanostructured Titanium Orthopaedic Implants. MATERIALS 2017; 10:ma10111302. [PMID: 29137166 PMCID: PMC5706249 DOI: 10.3390/ma10111302] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/01/2017] [Accepted: 11/08/2017] [Indexed: 02/06/2023]
Abstract
The surface design of titanium implants influences not only the local biological reactions but also affects at least the clinical result in orthopaedic application. During the last decades, strong efforts have been made to improve osteointegration and prevent bacterial adhesion to these surfaces. Following the rule of “smaller, faster, cheaper”, nanotechnology has encountered clinical application. It is evident that the hierarchical implant surface micro- and nanotopography orchestrate the biological cascades of early peri-implant endosseous healing or implant loosening. This review of the literature gives a brief overview of nanostructured titanium-base biomaterials designed to improve osteointegration and prevent from bacterial infection.
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2755
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Phage mobility is a core determinant of phage-bacteria coexistence in biofilms. ISME JOURNAL 2017; 12:531-543. [PMID: 29125597 PMCID: PMC5776469 DOI: 10.1038/ismej.2017.190] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/17/2017] [Accepted: 09/26/2017] [Indexed: 12/12/2022]
Abstract
Many bacteria are adapted for attaching to surfaces and for building complex communities, termed biofilms. The biofilm mode of life is predominant in bacterial ecology. So too is the exposure of bacteria to ubiquitous viral pathogens, termed bacteriophages. Although biofilm-phage encounters are likely to be common in nature, little is known about how phages might interact with biofilm-dwelling bacteria. It is also unclear how the ecological dynamics of phages and their hosts depend on the biological and physical properties of the biofilm environment. To make headway in this area, we develop a biofilm simulation framework that captures key mechanistic features of biofilm growth and phage infection. Using these simulations, we find that the equilibrium state of interaction between biofilms and phages is governed largely by nutrient availability to biofilms, infection likelihood per host encounter and the ability of phages to diffuse through biofilm populations. Interactions between the biofilm matrix and phage particles are thus likely to be of fundamental importance, controlling the extent to which bacteria and phages can coexist in natural contexts. Our results open avenues to new questions of host-parasite coevolution and horizontal gene transfer in spatially structured biofilm contexts.
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2756
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Wang P, Zeng Z, Wang W, Wen Z, Li J, Wang X. Dissemination and loss of a biofilm-related genomic island in marine Pseudoalteromonas mediated by integrative and conjugative elements. Environ Microbiol 2017; 19:4620-4637. [PMID: 28892292 DOI: 10.1111/1462-2920.13925] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 01/24/2023]
Abstract
Acquisition of genomic islands (GIs) plays a central role in the diversification and adaptation of bacteria. Some GIs can be mobilized in trans by integrative and conjugative elements (ICEs) or conjugative plasmids if the GIs carry specific transfer-related sequences. However, the transfer mechanism of GIs lacking such elements remains largely unexplored. Here, we investigated the transmissibility of a GI found in a coral-associated marine bacterium. This GI does not carry genes with transfer functions, but it carries four genes required for robust biofilm formation. Notably, this GI is inserted in the integration site for SXT/R391 ICEs. We demonstrated that acquisition of an SXT/R391 ICE results in either a tandem GI/ICE arrangement or the complete displacement of the GI. The GI displacement by the ICE greatly reduces biofilm formation. In contrast, the tandem integration of the ICE with the GI in cis allows the GI to hijack the transfer machinery of the ICE to excise, transfer and re-integrate into a new host. Collectively, our findings reveal that the integration of an ICE into a GI integration site enables rapid genome dynamics and a new mechanism by which SXT/R391 ICEs can augment genome plasticity.
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Affiliation(s)
- Pengxia Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Zhenshun Zeng
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Weiquan Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhongling Wen
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoxue Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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2757
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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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2758
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Esteban-Fernández A, Zorraquín-Peña I, González de Llano D, Bartolomé B, Moreno-Arribas MV. The role of wine and food polyphenols in oral health. Trends Food Sci Technol 2017. [DOI: 10.1016/j.tifs.2017.09.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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2759
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Meireles A, Fulgêncio R, Machado I, Mergulhão F, Melo L, Simões M. Characterization of the heterotrophic bacteria from a minimally processed vegetables plant. Lebensm Wiss Technol 2017. [DOI: 10.1016/j.lwt.2017.01.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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2760
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Ma W, Han Y, Ma W, Han H, Zhu H, Xu C, Li K, Wang D. Enhanced nitrogen removal from coal gasification wastewater by simultaneous nitrification and denitrification (SND) in an oxygen-limited aeration sequencing batch biofilm reactor. BIORESOURCE TECHNOLOGY 2017; 244:84-91. [PMID: 28779678 DOI: 10.1016/j.biortech.2017.07.083] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/11/2017] [Accepted: 07/17/2017] [Indexed: 06/07/2023]
Abstract
Simultaneous nitrification and denitrification (SND) for treating coal gasification wastewater (CGW) was achieved successfully in a lab-scale sequencing batch biofilm reactor (SBBR) by oxygen-limited aeration. SND efficiency increased gradually with the concentration of dissolved oxygen (DO) decreased from 4.5mg/L to 0.35mg/L. The maximum SND efficiency of 81.23% was obtained at DO concentration of 0.35mg/L, and the corresponding removal efficiency of NH4+-N and TN reached 76.91% and 70.23%, respectively. Meanwhile, COD was removed significantly and toxic compounds were degraded into biodegradable substances, which relieved effectively the inhibition on nitrogen removal. The results indicated that oxygen-limited condition performed greater toxic compounds and nitrogen removal compared with the aerobic condition. Furthermore, the results of scanning electron microscopic (SEM) and microbial community structure confirmed robust biofilm formation provided a suitable anoxic micro-environment for co-existence of nitrifying and denitrifying bacteria and organics degradation bacteria in the reactor at oxygen-limited condition.
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Affiliation(s)
- Weiwei Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yuxing Han
- School of Engineering, South China Agricultural University, Guangzhou 510642, China
| | - Wencheng Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hongjun Han
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Hao Zhu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Chunyan Xu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Kun Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Dexin Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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2761
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Vidakovic L, Singh PK, Hartmann R, Nadell CD, Drescher K. Dynamic biofilm architecture confers individual and collective mechanisms of viral protection. Nat Microbiol 2017; 3:26-31. [PMID: 29085075 PMCID: PMC5739289 DOI: 10.1038/s41564-017-0050-1] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 09/29/2017] [Indexed: 01/21/2023]
Affiliation(s)
- Lucia Vidakovic
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Praveen K Singh
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Raimo Hartmann
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Carey D Nadell
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany. .,Department of Biological Sciences, Dartmouth College, Hanover, NH, USA.
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany. .,Department of Physics, Philipps University Marburg, Marburg, Germany.
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2762
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Abstract
How do neighboring bacterial biofilms sense and communicate with each other? In a recent paper, Liu et al. (2017) demonstrate how electrical signaling allows communication of metabolic states between adjacent B. subtilis biofilms, providing a possible generalizable mechanism for communication in multispecies biofilms with interdependent metabolism.
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Affiliation(s)
- Elizabeth A Libby
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Jonathan Dworkin
- Department of Microbiology & Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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2763
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Lysinibacillus fusiformis M5 Induces Increased Complexity in Bacillus subtilis 168 Colony Biofilms via Hypoxanthine. J Bacteriol 2017; 199:JB.00204-17. [PMID: 28583948 DOI: 10.1128/jb.00204-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/30/2017] [Indexed: 12/18/2022] Open
Abstract
In recent years, biofilms have become a central subject of research in the fields of microbiology, medicine, agriculture, and systems biology, among others. The sociomicrobiology of multispecies biofilms, however, is still poorly understood. Here, we report a screening system that allowed us to identify soil bacteria which induce architectural changes in biofilm colonies when cocultured with Bacillus subtilis We identified the soil bacterium Lysinibacillus fusiformis M5 as an inducer of wrinkle formation in B. subtilis colonies mediated by a diffusible signaling molecule. This compound was isolated by bioassay-guided chromatographic fractionation. The elicitor was identified to be the purine hypoxanthine using mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. We show that the induction of wrinkle formation by hypoxanthine is not dependent on signal recognition by the histidine kinases KinA, KinB, KinC, and KinD, which are generally involved in phosphorylation of the master regulator Spo0A. Likewise, we show that hypoxanthine signaling does not induce the expression of biofilm matrix-related operons epsABCDEFGHIJKLMNO and tasA-sipW-tapA Finally, we demonstrate that the purine permease PbuO, but not PbuG, is necessary for hypoxanthine to induce an increase in wrinkle formation of B. subtilis biofilm colonies. Our results suggest that hypoxanthine-stimulated wrinkle development is not due to a direct induction of biofilm-related gene expression but rather is caused by the excess of hypoxanthine within B. subtilis cells, which may lead to cell stress and death.IMPORTANCE Biofilms are a bacterial lifestyle with high relevance regarding diverse human activities. Biofilms can be beneficial, for instance, in crop protection. In nature, biofilms are commonly found as multispecies communities displaying complex social behaviors and characteristics. The study of interspecies interactions will thus lead to a better understanding and use of biofilms as they occur outside laboratory conditions. Here, we present a screening method suitable for the identification of multispecies interactions and showcase L. fusiformis as a soil bacterium that is able to live alongside B. subtilis and modify the architecture of its biofilms.
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2764
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Gomez-Carretero S, Nybom R, Richter-Dahlfors A. Electroenhanced Antimicrobial Coating Based on Conjugated Polymers with Covalently Coupled Silver Nanoparticles Prevents Staphylococcus aureus Biofilm Formation. Adv Healthc Mater 2017; 6. [PMID: 28805046 DOI: 10.1002/adhm.201700435] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/02/2017] [Indexed: 11/11/2022]
Abstract
The incidence of hospital-acquired infections is to a large extent due to device-associated infections. Bacterial attachment and biofilm formation on surfaces of medical devices often act as seeding points of infection. To prevent such infections, coatings based on silver nanoparticles (AgNPs) are often applied, however with varying clinical success. Here, the traditional AgNP-based antibacterial technology is reimagined, now forming the base for an electroenhanced antimicrobial coating. To integrate AgNPs in an electrically conducting polymer layer, a simple, yet effective chemical strategy based on poly(hydroxymethyl 3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT-MeOH:PSS) and (3-aminopropyl)triethoxysilane is designed. The resultant PEDOT-MeOH:PSS-AgNP composite presents a consistent coating of covalently linked AgNPs, as shown by scanning electron microscopy and surface plasmon resonance analysis. The efficacy of the coatings, with and without electrical addressing, is then tested against Staphylococcus aureus, a major colonizer of medical implants. Using custom-designed culturing devices, a nearly complete prevention of biofilm growth is obtained in AgNP composite devices addressed with a square wave voltage input. It is concluded that this electroenhancement of the bactericidal effect of the coupled AgNPs offers a novel, efficient solution against biofilm colonization of medical implants.
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Affiliation(s)
- Salvador Gomez-Carretero
- Swedish Medical Nanoscience Center; Department of Neuroscience; Karolinska Institutet; 171 77 Stockholm Sweden
| | - Rolf Nybom
- Department of Neuroscience; Karolinska Institutet; 171 77 Stockholm Sweden
| | - Agneta Richter-Dahlfors
- Swedish Medical Nanoscience Center; Department of Neuroscience; Karolinska Institutet; 171 77 Stockholm Sweden
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2765
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Emery BDD, Furian TQ, Pilatti RM, Chitolina GZ, Borges KA, Salle CT, Moraes HL. Evaluation of the biofilm formation capacity of Pasteurella multocida strains isolated from cases of fowl cholera and swine lungs and its relationship with pathogenicity. PESQUISA VETERINARIA BRASILEIRA 2017. [DOI: 10.1590/s0100-736x2017001000001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT: Pasteurella multocida is a Gram-negative bacillus that causes economic losses due to the development of respiratory diseases in several animal species. Among the mechanisms of virulence, the formation of biofilms is an important factor for bacterial survival in hostile environments. Studies of biofilm formation by P. multocida are needed because P. multocida is an important pathogen involved in respiratory infections. However, in contrast to other microorganisms, few studies of biofilm formation have examined P. multocida. Studies comparing the pathogenicity of microbial strains as a function of their biofilm production capacity are also rare. Consequently, the aim of this study was to evaluate the biofilm formation capacity of 94 P. multocida strains isolated from cases of fowl cholera and from swine lungs on polystyrene plates. The associations of the biofilm formation capacity with the pathogenicity index (PI) in vivo and with the presence of four genes (screened by PCR) of the tad locus (tadB, tadD, tadE and tadG), described as adhesion markers, were also determined. Strains from both animal origins were able to form biofilms. However, most of the specimens (52.13%) were classified as weak producers, and more than 40% of the strains of P. multocida (40.42%) did not produce biofilms. There was no significant difference (p>0.05) in the degree of biofilm production between the two sources of isolation. Of the analyzed strains, 56.52% contained all four genes (tadB, tadD, tadE and tadG). The PI arithmetic mean of the strains classified as non-biofilm producers was significantly different (p<0.05) from the PI of moderate-producer strains. The PI of specimens classified as weak biofilm producers also differed significantly (p<0.05) from that of the moderate-producer strains. The results indicate that even though the P. multocida strains isolated from cases of fowl cholera and swine lungs formed biofilms on polystyrene surfaces, adhesion was usually weak. The genes tadB, tadD, tadE and tadG were not significantly associated (p>0.05) with the production of biofilms and with the origin of a given strain. Finally, low virulence strains may suggest a higher biofilm formation capacity on polystyrene plates.
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2766
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Pires DP, Melo L, Vilas Boas D, Sillankorva S, Azeredo J. Phage therapy as an alternative or complementary strategy to prevent and control biofilm-related infections. Curr Opin Microbiol 2017; 39:48-56. [PMID: 28964986 DOI: 10.1016/j.mib.2017.09.004] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 09/06/2017] [Indexed: 01/21/2023]
Abstract
The complex heterogeneous structure of biofilms confers to bacteria an important survival strategy. Biofilms are frequently involved in many chronic infections in consequence of their low susceptibility to antibiotics as well as resistance to host defences. The increasing need of novel and effective treatments to target these complex structures has led to a growing interest on bacteriophages (phages) as a strategy for biofilm control and prevention. Phages can be used alone, as a cocktail to broaden the spectra of activity, or in combination with other antimicrobials to improve their efficacy. Here, we summarize the studies involving the use of phages for the treatment or prevention of bacterial biofilms, highlighting the biofilm features that can be tackled with phages or combined therapy approaches.
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Affiliation(s)
- D P Pires
- CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal
| | - Ldr Melo
- CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal
| | - D Vilas Boas
- CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal
| | - S Sillankorva
- CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal
| | - J Azeredo
- CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal.
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2767
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Karwautz C, Kus G, Stöckl M, Neu TR, Lueders T. Microbial megacities fueled by methane oxidation in a mineral spring cave. ISME JOURNAL 2017; 12:87-100. [PMID: 28949325 PMCID: PMC5739006 DOI: 10.1038/ismej.2017.146] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/23/2017] [Accepted: 08/01/2017] [Indexed: 12/18/2022]
Abstract
Massive biofilms have been discovered in the cave of an iodine-rich former medicinal spring in southern Germany. The biofilms completely cover the walls and ceilings of the cave, giving rise to speculations about their metabolism. Here we report on first insights into the structure and function of the biofilm microbiota, combining geochemical, imaging and molecular analytics. Stable isotope analysis indicated that thermogenic methane emerging into the cave served as an important driver of biofilm formation. The undisturbed cavern atmosphere contained up to 3000 p.p.m. methane and was microoxic. A high abundance and diversity of aerobic methanotrophs primarily within the Methylococcales (Gammaproteobacteria) and methylotrophic Methylophilaceae (Betaproteobacteria) were found in the biofilms, along with a surprising diversity of associated heterotrophic bacteria. The highest methane oxidation potentials were measured for submerged biofilms on the cavern wall. Highly organized globular structures of the biofilm matrix were revealed by fluorescent lectin staining. We propose that the extracellular matrix served not only as an electron sink for nutrient-limited biofilm methylotrophs but potentially also as a diffusive barrier against volatilized iodine species. Possible links between carbon and iodine cycling in this peculiar habitat are discussed.
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Affiliation(s)
- Clemens Karwautz
- Institute of Groundwater Ecology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
| | - Günter Kus
- Bavarian Environment Agency (LfU), Department 10: Geological Survey, Hof/Saale, Germany
| | - Michael Stöckl
- Institute of Groundwater Ecology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
| | - Thomas R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research-UFZ, Magdeburg, Germany
| | - Tillmann Lueders
- Institute of Groundwater Ecology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
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2768
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Niederdorfer R, Besemer K, Battin TJ, Peter H. Ecological strategies and metabolic trade-offs of complex environmental biofilms. NPJ Biofilms Microbiomes 2017; 3:21. [PMID: 28955480 PMCID: PMC5612939 DOI: 10.1038/s41522-017-0029-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 08/17/2017] [Accepted: 08/23/2017] [Indexed: 01/29/2023] Open
Abstract
Microorganisms aggregated into matrix-enclosed biofilms dominate microbial life in most natural, engineered, and medical systems. Despite this, the ecological adaptations and metabolic trade-offs of the formation of complex biofilms are currently poorly understood. Here, exploring the dynamics of bacterial ribosomal RNA operon (rrn) copy numbers, we unravel the genomic underpinning of the formation and success of stream biofilms that contain hundreds of bacterial taxa. Experimenting with stream biofilms, we found that nascent biofilms in eutrophic systems had reduced lag phases and higher growth rates, and more taxa with higher rrn copy number than biofilms from oligotrophic systems. Based on these growth-related traits, our findings suggest that biofilm succession was dominated by slow-but-efficient bacteria likely with leaky functions, such as the production of extracellular polymeric substances at the cost of rapid growth. Expanding our experimental findings to biofilms from 140 streams, we found that rrn copy number distribution reflects functional trait allocation and ecological strategies of biofilms to be able to thrive in fluctuating environments. These findings suggest that alternative trade-offs dominating over rate-yield trade-offs contribute to the evolutionary success of stream biofilms. Analyzing natural biofilms containing many types of bacteria yields insights into microbial strategies for success in complex biofilms. The ecological adaptations and metabolic trade-offs involved in the formation of multi-bacterial biofilms in the environment are not well understood. Researchers in Switzerland and Austria, led by Tom Battin and Hannes Peter at the École Polytechnique Fédérale de Lausanne, performed genetic analysis of biofilms sampled from 140 streams. The biofilms contained hundreds of types of bacteria, unlike the mono-bacterial biofilms examined in many laboratory studies. Genetic analysis techniques revealed a diversity of metabolic strategies that allow bacteria to survive within the rich ecology of natural biofilms. Slow-growing but metabolically efficient bacteria that release more extracellular biofilm components thrive better than those adapted for quick growth alone. The findings significantly improve understanding of biofilm ecology in the natural environment.
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Affiliation(s)
- Robert Niederdorfer
- Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Limnology and Oceanography, University of Vienna, Vienna, Austria
| | | | - Tom J Battin
- Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Hannes Peter
- Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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2769
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Veve MP, Davis SL, Williams AM, McKinnon JE, Ghanem TA. Considerations for antibiotic prophylaxis in head and neck cancer surgery. Oral Oncol 2017; 74:181-187. [PMID: 28943204 DOI: 10.1016/j.oraloncology.2017.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 09/13/2017] [Indexed: 02/06/2023]
Abstract
Peri/post-operative antibiotic prophylaxis (POABP) has become standard practice for preventing surgical site infections (SSI) in head and neck cancer patients undergoing microvascular reconstruction, but few data exist on optimal POABP regimens. Current surgical prophylaxis guideline recommendations fail to account for the complexity of microvascular reconstruction relative to other head and neck procedures, specifically regarding wound classification and antibiotic duration. Selection of POABP spectrum is also controversial, and must balance the choice between too narrow, risking subsequent infection, or too broad, and possible unwanted effects (e.g. antibiotic resistance, Clostridium difficile-associated diarrhea). POABP regimens should retain activity against bacteria expected to colonize the upper respiratory/salivary tracts, which include Gram-positive organisms and facultative anaerobes. However, Gram-negative bacilli also contribute to SSI in this setting. POABP doses should be optimized in order to achieve therapeutic tissue concentrations at the surgical site. Antibiotics targeted towards methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa are not warranted for all patients. Prolonged POABP durations have shown no differences in SSI when compared to short POABP durations, but prolonged durations provide unnecessarily antibiotic exposure and risk for adverse effects. Given the lack of standardization behind antibiotic POABP in this setting and the potential for poor patient outcomes, this practice necessitates an additional focus of surgeons and antimicrobial stewardship programs. The purpose of this review is to provide an overview of POABP evidence and discuss pertinent clinical implications of appropriate use.
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Affiliation(s)
- Michael P Veve
- University of Tennessee Health Science Center, College of Pharmacy, Knoxville, TN, USA; University of Tennessee Medical Center, Knoxville, TN, USA.
| | - Susan L Davis
- Wayne State University, Detroit, MI, USA; Henry Ford Health System, Detroit, MI, USA
| | | | | | - Tamer A Ghanem
- Wayne State University, Detroit, MI, USA; Henry Ford Health System, Detroit, MI, USA
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2770
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Piszczek P, Lewandowska Ż, Radtke A, Jędrzejewski T, Kozak W, Sadowska B, Szubka M, Talik E, Fiori F. Biocompatibility of Titania Nanotube Coatings Enriched with Silver Nanograins by Chemical Vapor Deposition. NANOMATERIALS (BASEL, SWITZERLAND) 2017; 7:E274. [PMID: 28914821 PMCID: PMC5618385 DOI: 10.3390/nano7090274] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 09/09/2017] [Accepted: 09/12/2017] [Indexed: 02/03/2023]
Abstract
Bioactivity investigations of titania nanotube (TNT) coatings enriched with silver nanograins (TNT/Ag) have been carried out. TNT/Ag nanocomposite materials were produced by combining the electrochemical anodization and chemical vapor deposition methods. Fabricated coatings were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The release effect of silver ions from TNT/Ag composites immersed in bodily fluids, has been studied using inductively coupled plasma mass spectrometry (ICP-MS). The metabolic activity assay (MTT) was applied to determine the L929 murine fibroblasts adhesion and proliferation on the surface of TNT/Ag coatings. Moreover, the results of immunoassays (using peripheral blood mononuclear cells-PBMCs isolated from rats) allowed the estimation of the immunological activity of TNT/Ag surface materials. Antibacterial activity of TNT/Ag coatings with different morphological and structural features was estimated against two Staphylococcus aureus strains (ATCC 29213 and H9). The TNT/Ag nanocomposite layers produced revealed a good biocompatibility promoting the fibroblast adhesion and proliferation. A desirable anti-biofilm activity against the S. aureus reference strain was mainly noticed for these TiO₂ nanotube coatings, which contain dispersed Ag nanograins deposited on their surface.
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Affiliation(s)
- Piotr Piszczek
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, ul. Gagarina 7, 87-100 Toruń, Poland.
- Nano-implant Ltd., NIP 9562314777, Gagarina 5, 87-100 Toruń, Poland.
| | - Żaneta Lewandowska
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, ul. Gagarina 7, 87-100 Toruń, Poland.
| | - Aleksandra Radtke
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, ul. Gagarina 7, 87-100 Toruń, Poland.
- Nano-implant Ltd., NIP 9562314777, Gagarina 5, 87-100 Toruń, Poland.
| | - Tomasz Jędrzejewski
- Faculty of Biology and Environment Protection, Nicolaus Copernicus University in Toruń, ul. Lwowska 1, 87-100 Toruń, Poland.
| | - Wiesław Kozak
- Faculty of Biology and Environment Protection, Nicolaus Copernicus University in Toruń, ul. Lwowska 1, 87-100 Toruń, Poland.
| | - Beata Sadowska
- Faculty of Biology and Environmental Protection, University of Lódź, ul. S. Banacha 12/16, 90-237 Łódź, Poland.
| | - Magdalena Szubka
- August Chełkowski Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland.
| | - Ewa Talik
- Faculty of Biology and Environmental Protection, University of Lódź, ul. S. Banacha 12/16, 90-237 Łódź, Poland.
| | - Fabrizio Fiori
- Di.S.C.O.-Sezione di Biochimica, Biologia e Fisica, Università Politecnica delle Marche, 60131 Ancona, Italy.
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2771
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Osmotic Compounds Enhance Antibiotic Efficacy against Acinetobacter baumannii Biofilm Communities. Appl Environ Microbiol 2017; 83:AEM.01297-17. [PMID: 28733283 DOI: 10.1128/aem.01297-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 07/04/2017] [Indexed: 12/17/2022] Open
Abstract
Biofilm-associated infections are a clinical challenge, in part because a hydrated matrix protects the bacterial community from antibiotics. Herein, we evaluated how different osmotic compounds (maltodextrin, sucrose, and polyethylene glycol [PEG]) enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities. Established (24-h) test tube biofilms (strain ATCC 17978) were treated with osmotic compounds in the presence or absence of 10× the MIC of different antibiotics (50 μg/ml tobramycin, 20 μg/ml ciprofloxacin, 300 μg/ml chloramphenicol, 30 μg/ml nalidixic acid, or 100 μg/ml erythromycin). Combining antibiotics with hypertonic concentrations of the osmotic compounds for 24 h reduced the number of biofilm bacteria by 5 to 7 log (P < 0.05). Increasing concentrations of osmotic compounds improved the effect, but there was a trade-off with increasing solution viscosity, whereby low-molecular-mass compounds (sucrose, 400-Da PEG) worked better than higher-mass compounds (maltodextrin, 3,350-Da PEG). Ten other A. baumannii strains were similarly treated with 400-Da PEG and tobramycin, resulting in a mean 2.7-log reduction in recoverable bacteria compared with tobramycin treatment alone. Multivariate regression models with data from different osmotic compounds and nine antibiotics demonstrated that the benefit from combining hypertonic treatments with antibiotics is a function of antibiotic mass and lipophilicity (r2 > 0.82; P < 0.002), and the relationship was generalizable for biofilms formed by A. baumannii and Escherichia coli K-12. Augmenting topical antibiotic therapies with a low-mass hypertonic treatment may enhance the efficacy of antibiotics against wound biofilms, particularly when using low-mass hydrophilic antibiotics.IMPORTANCE Biofilms form a barrier that protects bacteria from environmental insults, including exposure to antibiotics. We demonstrated that multiple osmotic compounds can enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities, but viscosity is a limiting factor, and the most effective compounds have lower molecular mass. The synergism between osmotic compounds and antibiotics is also dependent on the hydrophobicity and mass of the antibiotics. The statistical models presented herein provide a basis for predicting the optimal combination of osmotic compounds and antibiotics against surface biofilms communities.
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2772
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Karampatzakis A, Song CZ, Allsopp LP, Filloux A, Rice SA, Cohen Y, Wohland T, Török P. Probing the internal micromechanical properties of Pseudomonas aeruginosa biofilms by Brillouin imaging. NPJ Biofilms Microbiomes 2017; 3:20. [PMID: 28900539 PMCID: PMC5591272 DOI: 10.1038/s41522-017-0028-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/03/2017] [Accepted: 08/08/2017] [Indexed: 12/17/2022] Open
Abstract
Biofilms are organised aggregates of bacteria that adhere to each other or surfaces. The matrix of extracellular polymeric substances that holds the cells together provides the mechanical stability of the biofilm. In this study, we have applied Brillouin microscopy, a technique that is capable of measuring mechanical properties of specimens on a micrometre scale based on the shift in frequency of light incident upon a sample due to thermal fluctuations, to investigate the micromechanical properties of an active, live Pseudomonas aeruginosa biofilm. Using this non-contact and label-free technique, we have extracted information about the internal stiffness of biofilms under continuous flow. No correlation with colony size was found when comparing the averages of Brillouin shifts of two-dimensional cross-sections of randomly selected colonies. However, when focusing on single colonies, we observed two distinct spatial patterns: in smaller colonies, stiffness increased towards their interior, indicating a more compact structure of the centre of the colony, whereas, larger (over 45 μm) colonies were found to have less stiff interiors. A specialized microscopy technique can monitor biofilm stiffness in a non-destructive manner, yielding insights into biofilm structure and development. The technique, called Brillouin imaging, uses changes in the frequency of light interacting with a substance to reveal fine detail about the material’s mechanical properties. Peter Török and colleagues at Imperial College London, with co-workers in Singapore, used Brillouin imaging to study biofilms of Pseudomonas aeruginosa bacteria at different stages in their life cycle. In young colonies, stiffness increased towards the interior of the biofilm, while mature colonies had less stiff interiors. The older biofilms may therefore have hollow interiors or may have been moving towards a phase of bacterial dispersal from the biofilm state. This non-disruptive method to study mechanical variations within and between living biofilms may help efforts to combat biofilms in clinical, environmental and industrial situations.
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Affiliation(s)
- A Karampatzakis
- Centre for BioImaging Sciences, National University of Singapore, Singapore, 117557 Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117557 Singapore.,Blackett Laboratory, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2BZ United Kingdom
| | - C Z Song
- Blackett Laboratory, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2BZ United Kingdom
| | - L P Allsopp
- Imperial College London, Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, South Kensington Campus, Flowers Building, SW7 2AZ London, United Kingdom
| | - A Filloux
- Imperial College London, Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, South Kensington Campus, Flowers Building, SW7 2AZ London, United Kingdom
| | - S A Rice
- Singapore Centre for Environmental Life Sciences Engineering and the School of Biological Sciences, Nanyang Technological University Singapore, Singapore, 637551 Singapore
| | - Y Cohen
- Singapore Centre for Environmental Life Sciences Engineering and the School of Biological Sciences, Nanyang Technological University Singapore, Singapore, 637551 Singapore
| | - T Wohland
- Centre for BioImaging Sciences, National University of Singapore, Singapore, 117557 Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117557 Singapore.,Department of Biological Sciences and Department of Chemistry, National University of Singapore, Singapore, 117346 Singapore
| | - P Török
- Blackett Laboratory, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2BZ United Kingdom
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2773
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The Proline Variant of the W[F/L/M][T/S]R Cyclic Di-GMP Binding Motif Suppresses Dependence on Signal Association for Regulator Function. J Bacteriol 2017; 199:JB.00344-17. [PMID: 28652300 DOI: 10.1128/jb.00344-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 06/19/2017] [Indexed: 12/21/2022] Open
Abstract
Vibrio vulnificus is an estuarine bacterium and potent opportunistic human pathogen. It enters the food chain by asymptomatically colonizing a variety of marine organisms, most notably oysters. Expression of the brp-encoded extracellular polysaccharide, which enhances cell-surface adherence, is regulated by cyclic di-GMP (c-di-GMP) and the activator BrpT. The Vibrio cholerae and Vibrio parahaemolyticus homologs VpsT and CpsQ, directly bind c-di-GMP via a novel W[F/L/M][T/S]R motif, and c-di-GMP binding is absolutely required for activity. Notably, BrpT belongs to a distinct subclass of VpsT-like regulators that harbor a proline in the third position of the c-di-GMP binding motif (WLPR), and the impact of this change on activity is unknown. We show that the brp locus is organized as two linked operons with BrpT specifically binding to promoters upstream of brpA and brpH Expression data and structural modeling suggested that BrpT might be less dependent on c-di-GMP binding for activity than VpsT or CpsQ. We show that the affinity of BrpT for c-di-GMP is low and that signal binding is not a requisite for BrpT function. Furthermore, a BrpT mutant engineered to carry a canonical WLTR motif (BrpTP124T) bound c-di-GMP with high affinity and its activity was now c-di-GMP dependent. Conversely, introduction of the WLPR motif into VpsT suppressed its dependence on c-di-GMP for activity. This is the first demonstration of reduced dependence on signal association for regulator function within this motif family. Thus, BrpT defines a new class of VpsT-like transcriptional regulators, and the WLPR motif variant may similarly liberate the activity of other subclass members.IMPORTANCE A Vibrio genome may encode nearly 100 proteins that make, break, and bind c-di-GMP, underscoring its central role in the physiology of these bacteria. The activity of the biofilm regulators VpsT of V. cholerae and CpsQ of V. parahaemolyticus is regulated by the direct binding of c-di-GMP via a novel W[F/L/M][T/S]R motif. The V. vulnificus homolog, BrpT, bears an unusual WLPR variant and remains active at low intracellular c-di-GMP levels. This suggests that the WLPR motif may also liberate the activity of other members of this subclass. A single point mutation at the 3rd position of the motif was sufficient to moderate dependence on c-di-GMP binding for activator function, highlighting the simplicity with which complex bacterial signaling networks can be rewired.
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2774
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Mining marine shell wastes for polyelectrolyte chitosan anti-biofoulants: Fabrication of high-performance economic and ecofriendly anti-biofouling coatings. Carbohydr Polym 2017; 172:352-364. [DOI: 10.1016/j.carbpol.2017.05.059] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/16/2017] [Accepted: 05/18/2017] [Indexed: 12/30/2022]
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2775
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Rampadarath S, Bandhoa K, Puchooa D, Jeewon R, Bal S. Early bacterial biofilm colonizers in the coastal waters of Mauritius. ELECTRON J BIOTECHN 2017. [DOI: 10.1016/j.ejbt.2017.06.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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2776
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Even C, Marlière C, Ghigo JM, Allain JM, Marcellan A, Raspaud E. Recent advances in studying single bacteria and biofilm mechanics. Adv Colloid Interface Sci 2017; 247:573-588. [PMID: 28754382 DOI: 10.1016/j.cis.2017.07.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 12/15/2022]
Abstract
Bacterial biofilms correspond to surface-associated bacterial communities embedded in hydrogel-like matrix, in which high cell density, reduced diffusion and physico-chemical heterogeneity play a protective role and induce novel behaviors. In this review, we present recent advances on the understanding of how bacterial mechanical properties, from single cell to high-cell density community, determine biofilm tri-dimensional growth and eventual dispersion and we attempt to draw a parallel between these properties and the mechanical properties of other well-studied hydrogels and living systems.
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2777
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Tecon R, Or D. Biophysical processes supporting the diversity of microbial life in soil. FEMS Microbiol Rev 2017; 41:599-623. [PMID: 28961933 PMCID: PMC5812502 DOI: 10.1093/femsre/fux039] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 07/10/2017] [Indexed: 12/13/2022] Open
Abstract
Soil, the living terrestrial skin of the Earth, plays a central role in supporting life and is home to an unimaginable diversity of microorganisms. This review explores key drivers for microbial life in soils under different climates and land-use practices at scales ranging from soil pores to landscapes. We delineate special features of soil as a microbial habitat (focusing on bacteria) and the consequences for microbial communities. This review covers recent modeling advances that link soil physical processes with microbial life (termed biophysical processes). Readers are introduced to concepts governing water organization in soil pores and associated transport properties and microbial dispersion ranges often determined by the spatial organization of a highly dynamic soil aqueous phase. The narrow hydrological windows of wetting and aqueous phase connectedness are crucial for resource distribution and longer range transport of microorganisms. Feedbacks between microbial activity and their immediate environment are responsible for emergence and stabilization of soil structure-the scaffolding for soil ecological functioning. We synthesize insights from historical and contemporary studies to provide an outlook for the challenges and opportunities for developing a quantitative ecological framework to delineate and predict the microbial component of soil functioning.
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Affiliation(s)
- Robin Tecon
- Soil and Terrestrial Environmental Physics, Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland
| | - Dani Or
- Soil and Terrestrial Environmental Physics, Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland
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2778
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Li Q, Becker T, Sand W. Quantification of cell-substratum interactions by atomic force microscopy. Colloids Surf B Biointerfaces 2017; 159:639-643. [PMID: 28865360 DOI: 10.1016/j.colsurfb.2017.08.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 08/08/2017] [Accepted: 08/14/2017] [Indexed: 11/15/2022]
Abstract
Microorganisms adhere to surfaces and, subsequently, form biofilms. This process is of major interest in biotechnology, environmental sciences and medicine. It is crucial to understand the mechanisms of interactions between substratum and cells or biofilms. By combining force mapping-based atomic force microscopy (AFM) with pyrite-modified cantilevers we quantified the adhesion forces between undenatured planktonic or biofilm cells of Sulfobacillus thermosulfidooxidans and the substratum pyrite with values of 2.6±0.3nN and 77.3±7.1pN, respectively. This was achieved under natural conditions without any artefact resulting from the use of denaturing chemicals such as glutaraldehyde. This new technique is unique for quantifying the real interaction forces between cells or biofilms and their substrata.
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Affiliation(s)
- Qian Li
- Biofilm Centre, Aquatische Biotechnologie, Universität Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany
| | - Thomas Becker
- Department of Chemistry/Nanochemistry Research Institute, Curtin University, Bentley, WA 6845, Australia
| | - Wolfgang Sand
- Biofilm Centre, Aquatische Biotechnologie, Universität Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany; College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
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2779
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Matilla MA. A technology for the investigation of biofilm transmission under shearing pressures. Microb Biotechnol 2017; 10:1451-1453. [PMID: 28840961 PMCID: PMC5658607 DOI: 10.1111/1751-7915.12848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 08/04/2017] [Indexed: 11/28/2022] Open
Abstract
Biofilm formation is a multifactorial and dynamic process. Stages of biofilm formation are highly regulated and include bacterial attachment to a target surface, formation of microcolonies, biofilm maturation and dispersion. This article highlights recent research by Gusnaniar et al., (2017) in which the authors develop a device to investigate bacterial biofilm transmission between surfaces under shearing pressures. The instrument can potentially be used to investigate the role of different genetic determinants and environmental cues on biofilm stability and transmission.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, Granada, 18008, Spain
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2780
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Martirani-Von Abercron SM, Marín P, Solsona-Ferraz M, Castañeda-Cataña MA, Marqués S. Naphthalene biodegradation under oxygen-limiting conditions: community dynamics and the relevance of biofilm-forming capacity. Microb Biotechnol 2017; 10:1781-1796. [PMID: 28840968 PMCID: PMC5658598 DOI: 10.1111/1751-7915.12842] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/21/2017] [Accepted: 07/25/2017] [Indexed: 11/27/2022] Open
Abstract
Toxic polycyclic aromatic hydrocarbons (PAHs) are frequently released into the environment from anthropogenic sources. PAH remediation strategies focus on biological processes mediated by bacteria. The availability of oxygen in polluted environments is often limited or absent, and only bacteria able to thrive in these conditions can be considered for bioremediation strategies. To identify bacterial strains able to degrade PAHs under oxygen‐limiting conditions, we set up enrichment cultures from samples of an oil‐polluted aquifer, using either anoxic or microaerophilic condition and with PAHs as the sole carbon source. Despite the presence of a significant community of nitrate‐reducing bacteria, the initial community, which was dominated by Betaproteobacteria, was incapable of PAH degradation under strict anoxic conditions, although a clear shift in the structure of the community towards an increase in the Alphaproteobacteria (Sphingomonadaceae), Actinobacteria and an uncultured group of Acidobacteria was observed in the enrichments. In contrast, growth under microaerophilic conditions with naphthalene as the carbon source evidenced the development of a biofilm structure around the naphthalene crystal. The enrichment process selected two co‐dominant groups which finally reached 97% of the bacterial communities: Variovorax spp. (54%, Betaproteobacteria) and Starkeya spp. (43%, Xanthobacteraceae). The two dominant populations were able to grow with naphthalene, although only Starkeya was able to reproduce the biofilm structure around the naphthalene crystal. The pathway for naphthalene degradation was identified, which included as essential steps dioxygenases with high affinity for oxygen, showing 99% identity with Xanthobacter polyaromaticivorans dbd cluster for PAH degradation. Our results suggest that the biofilm formation capacity of Starkeya provided a structure to allocate its cells at an appropriate distance from the toxic carbon source.
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Affiliation(s)
| | - Patricia Marín
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Marta Solsona-Ferraz
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Mayra-Alejandra Castañeda-Cataña
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Silvia Marqués
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, Granada, Spain
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2781
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Shammi M, Pan X, Mostofa KMG, Zhang D, Liu CQ. Photo-flocculation of microbial mat extracellular polymeric substances and their transformation into transparent exopolymer particles: Chemical and spectroscopic evidences. Sci Rep 2017; 7:9074. [PMID: 28831092 PMCID: PMC5567378 DOI: 10.1038/s41598-017-09066-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 07/21/2017] [Indexed: 11/13/2022] Open
Abstract
Upon exposure to sunlight extracellular polymeric substances (EPS) were partially transformed into transparent exopolymer particles (TEP) and unstable flocs of different sizes without the addition of any precursors. Parallel factor (PARAFAC) modelling of the sample fluorescence spectra identified humic-like and protein-like or tyrosine-like components in both untreated and irradiated EPS samples. After 58 hours of solar irradiation, humic-like substances were entirely decomposed, while the regenerated protein-like substance from EPS was the key component in the irradiated samples. Degradation and reformation of EPS occurred which was confirmed by the results of size exclusion chromatography, dissolved organic carbon, total protein and total polysaccharide analyses. Irradiated EPS was composed of -COOH or C = O (amide I band) and -NH and -CN (amide II band), while Fourier transform infrared spectroscopy (FTIR) of TEP revealed more acidic -COOH and -C-O groups, indicating typical acidic protein-like TEP. The regenerated protein-like substances could form complexes with free metals originating from degraded EPS in irradiated samples, which could be responsible for the formation of TEP/floc in the aqueous media. These results suggest that TEP/floc formation from EPS could occur by a complexation mechanism between dissolved organic matter and metals, thereby causing ionic charge neutralisation upon sunlight exposure.
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Affiliation(s)
- Mashura Shammi
- Laboratory of Bioremediation, Department of Environmental Pollution and Process Control, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi-830011, Xinjiang, P.R. China
- Department of Environmental Sciences, Jahangirnagar University, Dhaka, 1342, Bangladesh
- University of Chinese Academy of Sciences, Beijing, 100049, P.R. China
| | - Xiangliang Pan
- Laboratory of Bioremediation, Department of Environmental Pollution and Process Control, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi-830011, Xinjiang, P.R. China.
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, P.R. China.
| | - Khan M G Mostofa
- Institute of Surface-Earth System Science, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China.
| | - Daoyong Zhang
- Laboratory of Bioremediation, Department of Environmental Pollution and Process Control, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi-830011, Xinjiang, P.R. China
| | - Cong-Qiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, Guizhou, P.R. China
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2782
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Xu CG, Yang YB, Zhou YH, Hao MQ, Ren YZ, Wang XT, Chen JQ, Muhammad I, Wang S, Liu D, Li XB, Li YH. Comparative Proteomic Analysis Provides insight into the Key Proteins as Possible Targets Involved in Aspirin Inhibiting Biofilm Formation of Staphylococcus xylosus. Front Pharmacol 2017; 8:543. [PMID: 28871227 PMCID: PMC5566577 DOI: 10.3389/fphar.2017.00543] [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: 01/20/2017] [Accepted: 08/04/2017] [Indexed: 01/01/2023] Open
Abstract
Staphylococcus xylosus is an opportunistic pathogen that causes infection in humans and cow mastitis. And S. xylosus possesses a strong ability to form biofilms in vitro. As biofilm formation facilitates resistance to antimicrobial agents, the discovery of new medicinal properties for classic drugs is highly desired. Aspirin, which is the most common active component of non-steroidal anti-inflammatory compounds, affects the biofilm-forming capacity of various bacterial species. We have found that aspirin effectively inhibits biofilm formation of S. xylosus by Crystal violet (CV) staining and scanning electron microscopy analyses. The present study sought to elucidate possible targets of aspirin in suppressing S. xylosus biofilm formation. Based on an isobaric tag for relative and absolute quantitation (iTRAQ) fold-change of >1.2 or <0.8 (P-value < 0.05), 178 differentially expressed proteins, 111 down-regulated and 67 up-regulated, were identified after application of aspirin to cells at a 1/2 minimal inhibitory concentration. Gene ontology analysis indicated enrichment in metabolic processes for the majority of the differentially expressed proteins. We then used the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database to analyze a large number of differentially expressed proteins and identified genes involved in biosynthesis of amino acids pathway, carbon metabolism (pentose phosphate and glycolytic pathways, tricarboxylic acid cycle) and nitrogen metabolism (histidine metabolism). These novel proteins represent candidate targets in aspirin-mediated inhibition of S. xylosus biofilm formation at sub-MIC levels. The findings lay the foundation for further studies to identify potential aspirin targets.
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Affiliation(s)
- Chang-Geng Xu
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Yan-Bei Yang
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Yong-Hui Zhou
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Mei-Qi Hao
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Yong-Zhi Ren
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Xiao-Ting Wang
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Jian-Qing Chen
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Ishfaq Muhammad
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Shuai Wang
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
| | - Di Liu
- Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Xiu-Bo Li
- Feed Research Institute, Chinese Academy of Agricultural SciencesBeijing, China
| | - Yan-Hua Li
- College of Veterinary Medicine, Northeast Agricultural UniversityHarbin, China
- Heilongjiang Key Laboratory for Animal Disease Control and Pharmaceutical DevelopmentHarbin, China
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2783
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Rossi CC, Souza-Silva T, Araújo-Alves AV, Giambiagi-deMarval M. CRISPR-Cas Systems Features and the Gene-Reservoir Role of Coagulase-Negative Staphylococci. Front Microbiol 2017; 8:1545. [PMID: 28861060 PMCID: PMC5559504 DOI: 10.3389/fmicb.2017.01545] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/31/2017] [Indexed: 01/14/2023] Open
Abstract
The claimed role of gene reservoir of coagulase-negative staphylococci (CoNS) could be contradicted by estimates that CRISPR/Cas systems are found in the genomes of 40–50% of bacteria, as these systems interfere with plasmid uptake in staphylococci. To further correlate this role with presence of CRISPR, we analyzed, by computational methods, 122 genomes from 15 species of CoNS. Only 15% of them harbored CRISPR/Cas systems, and this proportion was much lower for S. epidermidis and S. haemolyticus, the CoNS most frequently associated with opportunistic infections in humans. These systems are of type II or III, and at least two of them are located within SCCmec, a mobile genetic element of Staphylococcus bacterial species. An analysis of the spacers of these CRISPRs, which come from exogenous origin, allowed us to track the transference of the SCCmec, which was exchanged between different strains, species and hosts. Some of the spacers are derived from plasmids described in Staphylococcus species that are different from those in which the CRISPR are found, evidencing the attempt (and failure) of plasmid transference between them. Based on the polymorphisms of the cas1 gene in CRISPRs of types II and III, we developed a multiplex polymerase chain reaction (PCR) suitable to screen and type CRISPR systems in CoNS. The PCR was tested in 59 S. haemolyticus strains, of which only two contained a type III cas1. This gene was shown to be expressed in the exponential growth, stationary phase and during biofilm formation. The low abundance of CRISPRs in CoNS is in accordance with their role as gene reservoirs, but when present, their spacers sequence evidence and give an insight on the dynamics of horizontal genetic transfer among staphylococci.
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Affiliation(s)
- Ciro C Rossi
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Thaysa Souza-Silva
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Amanda V Araújo-Alves
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Marcia Giambiagi-deMarval
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
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2784
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Schmidt SI, Cuthbert MO, Schwientek M. Towards an integrated understanding of how micro scale processes shape groundwater ecosystem functions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 592:215-227. [PMID: 28319709 DOI: 10.1016/j.scitotenv.2017.03.047] [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: 01/04/2017] [Revised: 03/05/2017] [Accepted: 03/06/2017] [Indexed: 06/06/2023]
Abstract
Micro scale processes are expected to have a fundamental role in shaping groundwater ecosystems and yet they remain poorly understood and under-researched. In part, this is due to the fact that sampling is rarely carried out at the scale at which microorganisms, and their grazers and predators, function and thus we lack essential information. While set within a larger scale framework in terms of geochemical features, supply with energy and nutrients, and exchange intensity and dynamics, the micro scale adds variability, by providing heterogeneous zones at the micro scale which enable a wider range of redox reactions. Here we outline how understanding micro scale processes better may lead to improved appreciation of the range of ecosystems functions taking place at all scales. Such processes are relied upon in bioremediation and we demonstrate that ecosystem modelling as well as engineering measures have to take into account, and use, understanding at the micro scale. We discuss the importance of integrating faunal processes and computational appraisals in research, in order to continue to secure sustainable water resources from groundwater.
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Affiliation(s)
- Susanne I Schmidt
- Centre for Systems Biology, University of Birmingham, Birmingham, UK.
| | - Mark O Cuthbert
- Connected Waters Initiative Research Centre, UNSW Australia, 110 King Street, Manly Vale 2093, Australia; Department of Geography, University College London, Gower Street, London, WC1E 6BT, UK
| | - Marc Schwientek
- Center of Applied Geoscience, University of Tübingen, 72074 Tübingen, Germany
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2785
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Lemon DJ, Yang X, Srivastava P, Luk YY, Garza AG. Polymertropism of rod-shaped bacteria: movement along aligned polysaccharide fibers. Sci Rep 2017; 7:7643. [PMID: 28801641 PMCID: PMC5554183 DOI: 10.1038/s41598-017-07486-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 06/16/2017] [Indexed: 01/11/2023] Open
Abstract
In nature, bacteria often live in surface-associated communities known as biofilms. Biofilm-forming bacteria typically deposit a layer of polysaccharide on the surfaces they inhabit; hence, polysaccharide is their immediate environment on many surfaces. In this study, we examined how the physical characteristics of polysaccharide substrates influence the behavior of the biofilm-forming bacterium Myxococcus xanthus. M. xanthus responds to the compression-induced deformation of polysaccharide substrates by preferentially spreading across the surface perpendicular to the axis of compression. Our results suggest that M. xanthus is not responding to the water that accumulates on the surface of the polysaccharide substrate after compression or to compression-induced changes in surface topography such as the formation of troughs. These directed surface movements do, however, consistently match the orientation of the long axes of aligned and tightly packed polysaccharide fibers in compressed substrates, as indicated by behavioral, birefringence and small angle X-ray scattering analyses. Therefore, we suggest that the directed movements are a response to the physical arrangement of the polymers in the substrate and refer to the directed movements as polymertropism. This behavior might be a common property of bacteria, as many biofilm-forming bacteria that are rod-shaped and motile on soft surfaces exhibit polymertropism.
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Affiliation(s)
- David J Lemon
- Department of Biology, Syracuse University, Syracuse, NY, 13244, United States
| | - Xingbo Yang
- Department of Physics, Syracuse University, Syracuse, NY, 13244, United States.,Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208, United States
| | - Pragya Srivastava
- Department of Physics, Syracuse University, Syracuse, NY, 13244, United States.,The Francis Crick Institute, London, NW1 1BF, United Kingdom
| | - Yan-Yeung Luk
- Department of Chemistry, Syracuse University, Syracuse, NY, 13244, United States.
| | - Anthony G Garza
- Department of Biology, Syracuse University, Syracuse, NY, 13244, United States.
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2786
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Biofilms in Endodontics-Current Status and Future Directions. Int J Mol Sci 2017; 18:ijms18081748. [PMID: 28800075 PMCID: PMC5578138 DOI: 10.3390/ijms18081748] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 07/31/2017] [Accepted: 08/08/2017] [Indexed: 01/05/2023] Open
Abstract
Microbiota are found in highly organized and complex entities, known as biofilms, the characteristics of which are fundamentally different from microbes in planktonic suspensions. Root canal infections are biofilm mediated. The complexity and variability of the root canal system, together with the multi-species nature of biofilms, make disinfection of this system extremely challenging. Microbial persistence appears to be the most important factor for failure of root canal treatment and this could further have an impact on pain and quality of life. Biofilm removal is accomplished by a chemo-mechanical process, using specific instruments and disinfecting chemicals in the form of irrigants and/or intracanal medicaments. Endodontic research has focused on the characterization of root canal biofilms and the clinical methods to disrupt the biofilms in addition to achieving microbial killing. In this narrative review, we discuss the role of microbial biofilms in endodontics and review the literature on the role of root canal disinfectants and disinfectant-activating methods on biofilm removal.
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2787
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2788
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Gusnaniar N, Sjollema J, Jong ED, Woudstra W, de Vries J, Nuryastuti T, van der Mei HC, Busscher HJ. Influence of biofilm lubricity on shear-induced transmission of staphylococcal biofilms from stainless steel to silicone rubber. Microb Biotechnol 2017; 10:1744-1752. [PMID: 28771954 PMCID: PMC5658628 DOI: 10.1111/1751-7915.12798] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 07/07/2017] [Indexed: 01/08/2023] Open
Abstract
In real-life situations, bacteria are often transmitted from biofilms growing on donor surfaces to receiver ones. Bacterial transmission is more complex than adhesion, involving bacterial detachment from donor and subsequent adhesion to receiver surfaces. Here, we describe a new device to study shear-induced bacterial transmission from a (stainless steel) pipe to a (silicone rubber) tube and compare transmission of EPS-producing and non-EPS-producing staphylococci. Transmission of an entire biofilm from the donor to the receiver tube did not occur, indicative of cohesive failure in the biofilm rather than of adhesive failure at the donor-biofilm interface. Biofilm was gradually transmitted over an increasing length of receiver tube, occurring mostly to the first 50 cm of the receiver tube. Under high-shearing velocity, transmission of non-EPS-producing bacteria to the second half decreased non-linearly, likely due to rapid thinning of the lowly lubricious biofilm. Oppositely, transmission of EPS-producing strains to the second tube half was not affected by higher shearing velocity due to the high lubricity and stress relaxation of the EPS-rich biofilms, ensuring continued contact with the receiver. The non-linear decrease of ongoing bacterial transmission under high-shearing velocity is new and of relevance in for instance, high-speed food slicers and food packaging.
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Affiliation(s)
- Niar Gusnaniar
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Jelmer Sjollema
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Ed D Jong
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Willem Woudstra
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Joop de Vries
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Titik Nuryastuti
- Department of Microbiology, Universitas Gadjah Mada Yogyakarta, Yogyakarta, Indonesia
| | - Henny C van der Mei
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Henk J Busscher
- University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
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2789
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Danielsen HN, Hansen SH, Herbst FA, Kjeldal H, Stensballe A, Nielsen PH, Dueholm MS. Direct Identification of Functional Amyloid Proteins by Label-Free Quantitative Mass Spectrometry. Biomolecules 2017; 7:biom7030058. [PMID: 28777328 PMCID: PMC5618239 DOI: 10.3390/biom7030058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 07/30/2017] [Accepted: 07/31/2017] [Indexed: 11/16/2022] Open
Abstract
Functional amyloids are important structural and functional components of many biofilms, yet our knowledge of these fascinating polymers is limited to a few examples for which the native amyloids have been isolated in pure form. Isolation of the functional amyloids from other cell components represents a major bottleneck in the search for new functional amyloid systems. Here we present a label-free quantitative mass spectrometry method that allows identification of amyloid proteins directly in cell lysates. The method takes advantage of the extreme structural stability and polymeric nature of functional amyloids and the ability of concentrated formic acid to depolymerize the amyloids. An automated data processing pipeline that provides a short list of amyloid protein candidates was developed based on an amyloid-specific sigmoidal abundance signature in samples treated with increasing concentrations of formic acid. The method was evaluated using the Escherichiacoli curli and the Pseudomonas Fap system. It confidently identified the major amyloid subunit for both systems, as well as the minor subunit for the curli system. A few non-amyloid proteins also displayed the sigmoidal abundance signature. However, only one of these contained a sec-dependent signal peptide, which characterizes most of all secreted proteins, including all currently known functional bacterial amyloids.
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Affiliation(s)
- Heidi N Danielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark.
| | - Susan H Hansen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark.
| | - Florian-Alexander Herbst
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark.
| | - Henrik Kjeldal
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark.
| | - Allan Stensballe
- Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark.
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark.
| | - Morten S Dueholm
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark.
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2790
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Dusane DH. CORR Insights ®: Does Extracellular DNA Production Vary in Staphylococcal Biofilms Isolated From Infected Implants versus Controls? Clin Orthop Relat Res 2017; 475:2114-2116. [PMID: 28429266 PMCID: PMC5498386 DOI: 10.1007/s11999-017-5360-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/14/2017] [Indexed: 01/31/2023]
Affiliation(s)
- Devendra H. Dusane
- 0000 0001 2285 7943grid.261331.4Center for Microbial Interface Biology, The Ohio State University, 460 West, 12th Ave., Columbus, OH 43210 USA
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2791
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Shi Y, Huang J, Zeng G, Gu Y, Chen Y, Hu Y, Tang B, Zhou J, Yang Y, Shi L. Exploiting extracellular polymeric substances (EPS) controlling strategies for performance enhancement of biological wastewater treatments: An overview. CHEMOSPHERE 2017; 180:396-411. [PMID: 28419953 DOI: 10.1016/j.chemosphere.2017.04.042] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/02/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Extracellular polymeric substances (EPS) are present both outside of the cells and in the interior of microbial aggregates, and account for a main component in microbial aggregates. EPS can influence the properties and functions of microbial aggregates in biological wastewater treatment systems, and specifically EPS are involved in biofilm formation and stability, sludge behaviors as well as sequencing batch reactors (SBRs) granulation whereas they are also responsible for membrane fouling in membrane bioreactors (MBRs). EPS exhibit dual roles in biological wastewater treatments, and hence the control of available EPS can be expected to lead to changes in microbial aggregate properties, thereby improving system performance. In this review, current updated knowledge with regard to EPS basics including their formation mechanisms, important properties, key component functions as well as sub-fraction differentiation is given. EPS roles in biological wastewater treatments are also briefly summarized. Special emphasis is laid on EPS controlling strategies which would have the great potential in promoting microbial aggregates performance and in alleviating membrane fouling, including limitation strategies (inhibition of quorum sensing (QS) systems, regulation of environmental conditions, enzymatic degradation of key components, energy uncoupling etc.) and elevation strategies (enhancement of QS systems, addition of exogenous agents etc.). Those strategies have been confirmed to be feasible and promising to enhance system performance, and they would be a research niche that deserves further study.
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Affiliation(s)
- Yahui Shi
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Jinhui Huang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
| | - Yanling Gu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Yaoning Chen
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Yi Hu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Bi Tang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Jianxin Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Ying Yang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Lixiu Shi
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
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2792
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Molina-Santiago C, Udaondo Z, Cordero BF, Ramos JL. Interspecies cross-talk between co-cultured Pseudomonas putida and Escherichia coli. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:441-448. [PMID: 28585781 DOI: 10.1111/1758-2229.12553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 05/26/2017] [Accepted: 05/28/2017] [Indexed: 06/07/2023]
Abstract
Pseudomonas putida and Escherichia coli are ubiquitous microorganisms that can be isolated from soil rhizosphere, the surface of vegetables, fresh waters and wastewaters - environments in which they likely co-exist. Despite this, the potential interactions between these microbes have not been studied in detail. To analyse these interactions, we carried out RNA-seq transcriptomic analysis of these microbes as monocultures and as co-cultures. Our results show that co-culture of these microbes significantly alters transcriptional profiles. The most dramatic transcriptional changes in both microorganisms were involved in central carbon metabolism, as well as adhesion to surfaces and the activation of drug efflux pumps. We also found that acetate production was one of the mechanisms used by E. coli K-12 MG1655 in response to the presence of P. putida DOT-T1E.
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Affiliation(s)
- Carlos Molina-Santiago
- Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, C/Profesor Albareda 1, Granada, E-18008, Spain
| | - Zulema Udaondo
- Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, C/Profesor Albareda 1, Granada, E-18008, Spain
| | - Baldo F Cordero
- Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, C/Profesor Albareda 1, Granada, E-18008, Spain
| | - Juan L Ramos
- Department of Environmental Protection, Consejo Superior de Investigaciones Científicas, C/Profesor Albareda 1, Granada, E-18008, Spain
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2793
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Liu W, Li S, Wang Z, Yan ECY, Leblanc RM. Characterization of Surface-Active Biofilm Protein BslA in Self-Assembling Langmuir Monolayer at the Air-Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7548-7555. [PMID: 28701036 DOI: 10.1021/acs.langmuir.7b01739] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Biofilm is an extracellular matrix of bacteria and serves as a protective shield of bacterial communities. It is crucial for microbial growth and one of the leading causes of human chronic infections as well. However, the structures and molecular mechanism of biofilm formation remain largely unknown. Here, we examined a protein, BslA, expressed in the biofilms of Bacillus subtilis. We characterized the Langmuir monolayers of BslA at the air/water interface. Using techniques in surface chemistry and spectroscopy, we found that BslA forms a stable and robust Langmuir monolayer at the air/water interface. Our results show that the BslA Langmuir monolayer underwent two-stage elasticity in the solid state phase upon mechanical compression: one is possibly due to the intermolecular interaction and the other is likely due to both the intermolecular compulsion and the intramolecular distortion. The Langmuir monolayer of BslA shows abrupt changes in rigidities and elasticities at ∼25 mN/m. This surface pressure is close to the one at which BlsA saturates the air/water interface as a self-assembled film without mechanical compression, corresponding to a mean molecular area of ∼700 Å2 per molecule. Based on the results of surface UV-visible spectroscopy and infrared reflective-absorption spectroscopy, we propose that the BslA Langmuir monolayer carries intermolecular elasticity before ∼25 mN/m and both intermolecular and intramolecular elasticity after ∼25 mN/m. These results provide valuable insights into the understanding of biofilm-associated protein under high mechanical force, shedding light on further investigation of biofilm structure and functionalities.
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Affiliation(s)
- Wei Liu
- Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Shanghao Li
- Department of Chemistry, University of Miami , 1301 Memorial Drive, Coral Gables, Florida 33146, United States
| | - Zhuguang Wang
- Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Elsa C Y Yan
- Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Roger M Leblanc
- Department of Chemistry, University of Miami , 1301 Memorial Drive, Coral Gables, Florida 33146, United States
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2794
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Bose RJ, Ravikumar R, Karuppagounder V, Bennet D, Rangasamy S, Thandavarayan RA. Lipid–polymer hybrid nanoparticle-mediated therapeutics delivery: advances and challenges. Drug Discov Today 2017; 22:1258-1265. [DOI: 10.1016/j.drudis.2017.05.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/25/2017] [Accepted: 05/26/2017] [Indexed: 12/24/2022]
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2795
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Strategies for Biofilm Inhibition and Virulence Attenuation of Foodborne Pathogen-Escherichia coli O157:H7. Curr Microbiol 2017; 74:1477-1489. [DOI: 10.1007/s00284-017-1314-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 07/19/2017] [Indexed: 10/19/2022]
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2796
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Radtke A, Jędrzejewski T, Kozak W, Sadowska B, Więckowska-Szakiel M, Talik E, Mäkelä M, Leskelä M, Piszczek P. Optimization of the Silver Nanoparticles PEALD Process on the Surface of 1-D Titania Coatings. NANOMATERIALS (BASEL, SWITZERLAND) 2017; 7:E193. [PMID: 28737725 PMCID: PMC5535259 DOI: 10.3390/nano7070193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 07/14/2017] [Accepted: 07/20/2017] [Indexed: 01/04/2023]
Abstract
Plasma enhanced atomic layer deposition (PEALD) of silver nanoparticles on the surface of 1-D titania coatings, such as nanotubes (TNT) and nanoneedles (TNN), has been carried out. The formation of TNT and TNN layers enriched with dispersed silver particles of strictly defined sizes and the estimation of their bioactivity was the aim of our investigations. The structure and the morphology of produced materials were determined using X-ray photoelectron spectroscopy (XPS) and scanning electron miscroscopy (SEM). Their bioactivity and potential usefulness in the modification of implants surface have been estimated on the basis of the fibroblasts adhesion and proliferation assays, and on the basis of the determination of their antibacterial activity. The cumulative silver release profiles have been checked with the use of inductively coupled plasma-mass spectrometry (ICPMS), in order to exclude potential cytotoxicity of silver decorated systems. Among the studied nanocomposite samples, TNT coatings, prepared at 3, 10, 12 V and enriched with silver nanoparticles produced during 25 cycles of PEALD, revealed suitable biointegration properties and may actively counteract the formation of bacterial biofilm.
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Affiliation(s)
- Aleksandra Radtke
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland.
- Nano-Implant Ltd., Gagarina 5, 87-100 Toruń, Poland.
| | - Tomasz Jędrzejewski
- Faculty of Biology and Environmental Protection, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland.
| | - Wiesław Kozak
- Faculty of Biology and Environmental Protection, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland.
| | - Beata Sadowska
- Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Łódź, Poland.
| | - Marzena Więckowska-Szakiel
- Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Łódź, Poland.
| | - Ewa Talik
- A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.
| | - Maarit Mäkelä
- Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland.
| | - Markku Leskelä
- Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland.
| | - Piotr Piszczek
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland.
- Nano-Implant Ltd., Gagarina 5, 87-100 Toruń, Poland.
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2797
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Bridier A, Piard JC, Pandin C, Labarthe S, Dubois-Brissonnet F, Briandet R. Spatial Organization Plasticity as an Adaptive Driver of Surface Microbial Communities. Front Microbiol 2017; 8:1364. [PMID: 28775718 PMCID: PMC5517491 DOI: 10.3389/fmicb.2017.01364] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/05/2017] [Indexed: 01/08/2023] Open
Abstract
Biofilms are dynamic habitats which constantly evolve in response to environmental fluctuations and thereby constitute remarkable survival strategies for microorganisms. The modulation of biofilm functional properties is largely governed by the active remodeling of their three-dimensional structure and involves an arsenal of microbial self-produced components and interconnected mechanisms. The production of matrix components, the spatial reorganization of ecological interactions, the generation of physiological heterogeneity, the regulation of motility, the production of actives enzymes are for instance some of the processes enabling such spatial organization plasticity. In this contribution, we discussed the foundations of architectural plasticity as an adaptive driver of biofilms through the review of the different microbial strategies involved. Moreover, the possibility to harness such characteristics to sculpt biofilm structure as an attractive approach to control their functional properties, whether beneficial or deleterious, is also discussed.
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Affiliation(s)
- Arnaud Bridier
- Antibiotics, Biocides, Residues and Resistance Unit, Fougères Laboratory, ANSESFougères, France
| | - Jean-Christophe Piard
- Micalis Institute, INRA, AgroParisTech, Université Paris-SaclayJouy-en-Josas, France
| | - Caroline Pandin
- Micalis Institute, INRA, AgroParisTech, Université Paris-SaclayJouy-en-Josas, France
| | - Simon Labarthe
- MaIAGE, INRA, Université Paris-SaclayJouy-en-Josas, France
| | | | - Romain Briandet
- Micalis Institute, INRA, AgroParisTech, Université Paris-SaclayJouy-en-Josas, France
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2798
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Visualizing Antimicrobials in Bacterial Biofilms: Three-Dimensional Biochemical Imaging Using TOF-SIMS. mSphere 2017; 2:mSphere00211-17. [PMID: 28744481 PMCID: PMC5518269 DOI: 10.1128/msphere.00211-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/25/2017] [Indexed: 11/20/2022] Open
Abstract
Modern analytical techniques are becoming increasingly important in the life sciences; imaging mass spectrometry offers the opportunity to gain unprecedented amounts of information on the distribution of chemicals in samples—both xenobiotics and endogenous compounds. In particular, simultaneous imaging of antibiotics (and other antimicrobial compounds) and bacterium-derived metabolites in complex biological samples could be very important in the future for helping to understand how sample matrices impact the survival of bacteria under antibiotic challenge. We have shown that an imaging mass spectrometric technique, TOF-SIMS, will be potentially extremely valuable for this kind of research in the future. Bacterial biofilms are groups of bacteria that exist within a self-produced extracellular matrix, adhering to each other and usually to a surface. They grow on medical equipment and inserts such as catheters and are responsible for many persistent infections throughout the body, as they can have high resistance to many antimicrobials. Pseudomonas aeruginosa is an opportunistic pathogen that can cause both acute and chronic infections and is used as a model for research into biofilms. Direct biochemical methods of imaging of molecules in bacterial biofilms are of high value in gaining a better understanding of the fundamental biology of biofilms and biochemical gradients within them. Time of flight–secondary-ion mass spectrometry (TOF-SIMS) is one approach, which combines relatively high spatial resolution and sensitivity and can perform depth profiling analysis. It has been used to analyze bacterial biofilms but has not yet been used to study the distribution of antimicrobials (including antibiotics and the antimicrobial metal gallium) within biofilms. Here we compared two methods of imaging of the interior structure of P. aeruginosa in biological samples using TOF-SIMS, looking at both antimicrobials and endogenous biochemicals: cryosectioning of tissue samples and depth profiling to give pseudo-three-dimensional (pseudo-3D) images. The sample types included both simple biofilms grown on glass slides and bacteria growing in tissues in an ex vivo pig lung model. The two techniques for the 3D imaging of biofilms are potentially valuable complementary tools for analyzing bacterial infection. IMPORTANCE Modern analytical techniques are becoming increasingly important in the life sciences; imaging mass spectrometry offers the opportunity to gain unprecedented amounts of information on the distribution of chemicals in samples—both xenobiotics and endogenous compounds. In particular, simultaneous imaging of antibiotics (and other antimicrobial compounds) and bacterium-derived metabolites in complex biological samples could be very important in the future for helping to understand how sample matrices impact the survival of bacteria under antibiotic challenge. We have shown that an imaging mass spectrometric technique, TOF-SIMS, will be potentially extremely valuable for this kind of research in the future.
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2799
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Pallavicini P, Bassi B, Chirico G, Collini M, Dacarro G, Fratini E, Grisoli P, Patrini M, Sironi L, Taglietti A, Moritz M, Sorzabal-Bellido I, Susarrey-Arce A, Latter E, Beckett AJ, Prior IA, Raval R, Diaz Fernandez YA. Modular approach for bimodal antibacterial surfaces combining photo-switchable activity and sustained biocidal release. Sci Rep 2017; 7:5259. [PMID: 28701753 PMCID: PMC5507905 DOI: 10.1038/s41598-017-05693-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/22/2017] [Indexed: 02/06/2023] Open
Abstract
Photo-responsive antibacterial surfaces combining both on-demand photo-switchable activity and sustained biocidal release were prepared using sequential chemical grafting of nano-objects with different geometries and functions. The multi-layered coating developed incorporates a monolayer of near-infrared active silica-coated gold nanostars (GNS) decorated by silver nanoparticles (AgNP). This modular approach also enables us to unravel static and photo-activated contributions to the overall antibacterial performance of the surfaces, demonstrating a remarkable synergy between these two mechanisms. Complementary microbiological and imaging evaluations on both planktonic and surface-attached bacteria provided new insights on these distinct but cooperative effects.
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Affiliation(s)
- Piersandro Pallavicini
- Department of Chemistry and Centre for Health Technology, University of Pavia, Pavia, Italy.
| | - Barbara Bassi
- Department of Chemistry and Centre for Health Technology, University of Pavia, Pavia, Italy
| | | | | | - Giacomo Dacarro
- Department of Chemistry and Centre for Health Technology, University of Pavia, Pavia, Italy
| | - Emiliano Fratini
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence, Florence, Italy
| | - Pietro Grisoli
- Department of Pharmaceutical Sciences, University of Pavia, Pavia, Italy
| | | | - Laura Sironi
- Department of Physics, University Milano-Bicocca, Milano, Italy
| | - Angelo Taglietti
- Department of Chemistry and Centre for Health Technology, University of Pavia, Pavia, Italy.
| | - Marcel Moritz
- Open Innovation Hub for Antimicrobial Surfaces, University of Liverpool, Liverpool, UK
| | | | - Arturo Susarrey-Arce
- Open Innovation Hub for Antimicrobial Surfaces, University of Liverpool, Liverpool, UK
| | - Edward Latter
- Open Innovation Hub for Antimicrobial Surfaces, University of Liverpool, Liverpool, UK
| | - Alison J Beckett
- Biomedical EM Unit, School of Biomedical Sciences, University of Liverpool, Liverpool, UK
| | - Ian A Prior
- Biomedical EM Unit, School of Biomedical Sciences, University of Liverpool, Liverpool, UK
| | - Rasmita Raval
- Open Innovation Hub for Antimicrobial Surfaces, University of Liverpool, Liverpool, UK.
| | - Yuri A Diaz Fernandez
- Open Innovation Hub for Antimicrobial Surfaces, University of Liverpool, Liverpool, UK.
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2800
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Abstract
Biofilms are communities of microbial cells that are encapsulated within a self-produced polymeric matrix. The matrix is critical to the success of biofilms in diverse habitats; however, many details of the composition, structure, and function remain enigmatic. Biofilms formed by the Gram-positive bacterium Bacillus subtilis depend on the production of the secreted film-forming protein BslA. Here, we show that a gradient of electron acceptor availability through the depth of the biofilm gives rise to two distinct functional roles for BslA and that these roles can be genetically separated through targeted amino acid substitutions. We establish that monomeric BslA is necessary and sufficient to give rise to complex biofilm architecture, whereas dimerization of BslA is required to render the community hydrophobic. Dimerization of BslA, mediated by disulfide bond formation, depends on two conserved cysteine residues located in the C-terminal region. Our findings demonstrate that bacteria have evolved multiple uses for limited elements in the matrix, allowing for alternative responses in a complex, changing environment.
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