1
|
Gaillac A, Gourin C, Dubreil L, Briandet R, Prévost H, Jaffrès E. Biofilm formation of the food spoiler Brochothrix thermosphacta on different industrial surface materials using a biofilm reactor. Food Microbiol 2024; 120:104457. [PMID: 38431311 DOI: 10.1016/j.fm.2023.104457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/15/2023] [Accepted: 12/22/2023] [Indexed: 03/05/2024]
Abstract
Brochothrix thermosphacta is considered as a major food spoiler bacteria. This study evaluates biofilm formation by B. thermosphacta CD337(2) - a strong biofilm producer strain - on three food industry materials (polycarbonate (PC), polystyrene (PS), and stainless steel (SS)). Biofilms were continuously grown under flow at 25 °C in BHI broth in a modified CDC biofilm reactor. Bacterial cells were enumerated by plate counting, and biofilm spatial organization was deciphered by combining confocal laser scanning microscopy and image analysis. The biofilms had the same growth kinetics on all three materials and reach 8log CFU/cm2 as maximal concentration. Highly structured biofilms were observed on PC and PS, but less structured ones on SS. This difference was confirmed by structural quantification analysis using the image analysis software tool BiofilmQ. Biofilm on SS show less roughness, density, thickness and volume. The biofilm 3D structure seemed to be related to the coupon topography and roughness. The materials used in this study do not affect biofilm growth. However, their roughness and topography affect the biofilm architecture, which could influence biofilm behaviour.
Collapse
Affiliation(s)
| | | | | | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | | | | |
Collapse
|
2
|
Cen C, Wang X, Li H, Chen J, Wang Y. An inhibitor of the adaptability of Pseudomonas fluorescens in a high-salt environment. Phenomenon and mechanism of inhibition. Int J Food Microbiol 2024; 412:110553. [PMID: 38181519 DOI: 10.1016/j.ijfoodmicro.2023.110553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/13/2023] [Accepted: 12/21/2023] [Indexed: 01/07/2024]
Abstract
Pseudomonas fluorescens is a spoilage bacterium in food that has the ability to maintain growth and reproduction in high-salt environments. It acts as a defence mechanism through the exclusion of ions and the formation of biofilms. Hence, disrupting this defence mechanism may be a good way to control food spoilage. In this study, a specific flavonoid small molecule baicalin was found, which was able to dismantle the defence mechanism of the bacteria at a lower concentration (400 μM) of treatment. In synergy with salt, baicalin showed a significant inhibitory effect on the growth, c-di-gmp synthetics and biofilm formation of Pseudomonas fluorescens Pf08. Through transcriptomics, we also found that baicalein interfered with bacterial transport and polysaccharide production functions. Through molecular docking and QPCR, we found that baicalin is able to binding with the RpoS protein through hydrogen bonding and thus interfere with its function.
Collapse
Affiliation(s)
- Congnan Cen
- School of Food and Health, Beijing Technology and Business University, Beijing 100048, PR China; Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, PR China
| | - Xinxuan Wang
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, PR China
| | - Huan Li
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, PR China
| | - Jian Chen
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, PR China
| | - Yanbo Wang
- School of Food and Health, Beijing Technology and Business University, Beijing 100048, PR China; Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, PR China.
| |
Collapse
|
3
|
Palanisamy V, Bosilevac JM, Barkhouse DA, Velez SE, Chitlapilly Dass S. Shotgun-metagenomics reveals a highly diverse and communal microbial network present in the drains of three beef-processing plants. Front Cell Infect Microbiol 2023; 13:1240138. [PMID: 37743870 PMCID: PMC10515220 DOI: 10.3389/fcimb.2023.1240138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/08/2023] [Indexed: 09/26/2023] Open
Abstract
Background Multi-species biofilms pose a problem in various environments, especially food-processing environments. The diversity of microorganisms in these biofilms plays a critical role in their integrity and protection against external biotic and abiotic factors. Compared to single-species biofilms, mixed-species biofilms are more resistant to various stresses, including antimicrobials like sanitizers. Therefore, understanding the microbiome composition and diversity in biofilms and their metabolic potential is a priority when developing intervention techniques to combat foodborne pathogens in food processing environments. Methods This study aimed to describe and compare the microbiome profile of 75 drain biofilm samples obtained from five different locations (Hotscale, Hotbox, Cooler, Processing, & Grind room) of three beef-processing plants (Plant A, B & C) taken over two timepoints 2017-18 (T1) and 2021 (T2) by shotgun sequencing. Results Core microbiome analysis found Pseudomonas, Psychrobacter, and Acinetobacter to be the top three prevalent genera among the plants and locations. Alpha diversity analysis demonstrated a high diversity of microbiome present in all the plants and locations across the time points. Functional analysis showed the high metabolic potential of the microbial community with abundance of genes in metabolism, cell-adhesion, motility, and quorum sensing. Moreover, Quaternary Ammonium Compound (QAC) resistance genes were also observed, this is significant as QAC sanitizers are commonly used in many food processing facilities. Multi-functional genes such as transposases, polymerases, permeases, flagellar proteins, and Mobile Genetic Elements (MGEs) were found suggesting these are dynamic microbial communities that work together to protect themselves against environmental stresses through multiple defense mechanisms. Conclusion This study provides a framework for understanding the collective microbial network spanning a beef processing system. The results can be used to develop intervention strategies to best control these highly communicative microbial networks.
Collapse
Affiliation(s)
- Vignesh Palanisamy
- Department of Animal Science, Texas A&M University, College Station, TX, United States
| | - Joseph M. Bosilevac
- U. S. Department of Agriculture, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Lincoln, NE, United States
| | - Darryll A. Barkhouse
- Molecular Center of Excellence, Invisible Sentinel, bioMerieux Inc., Philadelphia, PA, United States
| | - Sarah E. Velez
- Molecular Center of Excellence, Invisible Sentinel, bioMerieux Inc., Philadelphia, PA, United States
| | | |
Collapse
|
4
|
Jalilian F, Valeo C, Chu A, Bhiladvala R. Sensors for Biomass Monitoring in Vegetated Green Infrastructure: A Review. SENSORS (BASEL, SWITZERLAND) 2023; 23:6404. [PMID: 37514698 PMCID: PMC10385927 DOI: 10.3390/s23146404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023]
Abstract
Bioretention cells, or rain gardens, can effectively reduce many contaminants in polluted stormwater through phytoremediation and bioremediation. The vegetated soil structure develops bacterial communities both within the soil and around the vegetation roots that play a significant role in the bioremediative process. Prediction of a bioretention cell's performance and efficacy is essential to the design process, operation, and maintenance throughout the design life of the cell. One of the key hurdles to these important issues and, therefore, to appropriate designs, is the lack of effective and inexpensive devices for monitoring and quantitatively assessing this bioremediative process in the field. This research reviews the available technologies for biomass monitoring and assesses their potential for quantifying bioremediative processes in rain gardens. The methods are discussed based on accuracy and calibration requirements, potential for use in situ, in real-time, and for characterizing biofilm formation in media that undergoes large fluctuations in nutrient supply. The methods discussed are microscopical, piezoelectric, fiber-optic, thermometric, and electrochemical. Microscopical methods are precluded from field use but would be essential to the calibration and verification of any field-based sensor. Piezoelectric, fiber-optic, thermometric, and some of the electrochemical-based methods reviewed come with limitations by way of support mechanisms or insufficient detection limits. The impedance-based electrochemical method shows the most promise for applications in rain gardens, and it is supported by microscopical methods for calibration and validation.
Collapse
Affiliation(s)
- Farhad Jalilian
- Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Caterina Valeo
- Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Angus Chu
- Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Rustom Bhiladvala
- Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada
| |
Collapse
|
5
|
Abu Quba AA, Goebel MO, Karagulyan M, Miltner A, Kästner M, Bachmann J, Schaumann GE, Diehl D. Changes in cell surface properties of Pseudomonas fluorescens by adaptation to NaCl induced hypertonic stress. FEMS MICROBES 2022; 4:xtac028. [PMID: 37333443 PMCID: PMC10169395 DOI: 10.1093/femsmc/xtac028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 10/26/2022] [Accepted: 12/05/2022] [Indexed: 10/12/2023] Open
Abstract
Determination of the effect of water stress on the surface properties of bacteria is crucial to study bacterial induced soil water repellency. Changes in the environmental conditions may affect several properties of bacteria such as the cell hydrophobicity and morphology. Here, we study the influence of adaptation to hypertonic stress on cell wettability, shape, adhesion, and surface chemical composition of Pseudomonas fluorescens. From this we aim to discover possible relations between the changes in wettability of bacterial films studied by contact angle and single cells studied by atomic and chemical force microscopy (AFM, CFM), which is still lacking. We show that by stress the adhesion forces of the cell surfaces towards hydrophobic functionalized probes increase while they decrease towards hydrophilic functionalized tips. This is consistent with the contact angle results. Further, cell size shrunk and protein content increased upon stress. The results suggest two possible mechanisms: Cell shrinkage is accompanied by the release of outer membrane vesicles by which the protein to lipid ratio increases. The higher protein content increases the rigidity and the number of hydrophobic nano-domains per surface area.
Collapse
Affiliation(s)
- Abd Alaziz Abu Quba
- Institute of Environmental Sciences, Rheinland-pfälzische Technische Universität Kaiserslauter-Landau, RPTU in Landau, Fortstrasse 7, 76829 Landau, Germany
| | - Marc-Oliver Goebel
- Institute of Soil Science, Leibniz Universität Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany
| | - Mariam Karagulyan
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Biotechnology, Permoserstraße 15, 04318 Leipzig, Germany
| | - Anja Miltner
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Biotechnology, Permoserstraße 15, 04318 Leipzig, Germany
| | - Matthias Kästner
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Biotechnology, Permoserstraße 15, 04318 Leipzig, Germany
| | - Jörg Bachmann
- Institute of Soil Science, Leibniz Universität Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany
| | - Gabriele E Schaumann
- Institute of Environmental Sciences, Rheinland-pfälzische Technische Universität Kaiserslauter-Landau, RPTU in Landau, Fortstrasse 7, 76829 Landau, Germany
| | - Doerte Diehl
- Institute of Environmental Sciences, Rheinland-pfälzische Technische Universität Kaiserslauter-Landau, RPTU in Landau, Fortstrasse 7, 76829 Landau, Germany
| |
Collapse
|
6
|
Parihar J, Kumawat A, Misra KP, Bagaria A. Synthesis and Characterization of Zinc Oxide Nanoparticles Using Thermophilic Bacteria Isolated from Arid Region of Rajasthan. ChemistrySelect 2022. [DOI: 10.1002/slct.202200419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jagdish Parihar
- Department of Physics Manipal University Jaipur Jaipur 303007 Rajasthan India
- Department of Bioscience & Bioengineering Indian Institute of Technology (IIT) – Jodhpur Jodhpur 342001 Rajasthan India
| | - Ashok Kumawat
- Department of Physics Manipal University Jaipur Jaipur 303007 Rajasthan India
| | | | - Ashima Bagaria
- Department of Physics Manipal University Jaipur Jaipur 303007 Rajasthan India
| |
Collapse
|
7
|
Screening inhibitor to prevent the psychrotrophic growth of Pseudomonas fluorescens by using molecular simulation. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
8
|
Borotová P, Galovičová L, Vukovic NL, Vukic M, Tvrdá E, Kačániová M. Chemical and Biological Characterization of Melaleuca alternifolia Essential Oil. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11040558. [PMID: 35214891 PMCID: PMC8880210 DOI: 10.3390/plants11040558] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/14/2022] [Accepted: 02/18/2022] [Indexed: 06/12/2023]
Abstract
The essential oil of Melaleuca alternifolia, commonly known as tea tree oil, has many beneficial properties due to its bioactive compounds. The aim of this research was to characterize the tea tree essential oil (TTEO) from Slovakia and its biological properties, which are specific to the chemical composition of essential oil. Gas chromatography/mass spectroscopy revealed that terpinen-4-ol was dominant with a content of 40.3%. γ-Terpinene, 1,8-cineole, and p-cymene were identified in contents of 11.7%, 7.0%, and 6.2%, respectively. Antioxidant activity was determined at 41.6% radical inhibition, which was equivalent to 447 μg Trolox to 1 mL sample. Antimicrobial activity was observed by the disk diffusion method against Gram-positive (G+), Gram-negative (G-) bacteria and against yeasts, where the best antimicrobial activity was against Enterococcus faecalis and Candida albicans with an inhibition zone of 10.67 mm. The minimum inhibitory concentration showed better susceptibility by G+ and G- planktonic cells, while yeast species and biofilm-forming bacteria strains were more resistant. Antibiofilm activity was observed against Pseudomonas fluorescens and Salmonella enterica by MALDI-TOF, where degradation of the protein spectra after the addition of essential oil was obtained. Good biological properties of tea tree essential oil allow its use in the food industry or in medicine as an antioxidant and antimicrobial agent.
Collapse
Affiliation(s)
- Petra Borotová
- AgroBioTech Research Centre, Slovak University of Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
- Faculty of Biotechnology and Food Sciences, Institute of Applied Biology, Slovak University of Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia;
| | - Lucia Galovičová
- Faculty of Horticulture and Landscape Engineering, Institute of Horticulture, Slovak University of Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia;
| | - Nenad L. Vukovic
- Department of Chemistry, Faculty of Science, University of Kragujevac, 34000 Kragujevac, Serbia; (N.L.V.); (M.V.)
| | - Milena Vukic
- Department of Chemistry, Faculty of Science, University of Kragujevac, 34000 Kragujevac, Serbia; (N.L.V.); (M.V.)
| | - Eva Tvrdá
- Faculty of Biotechnology and Food Sciences, Institute of Applied Biology, Slovak University of Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia;
| | - Miroslava Kačániová
- Faculty of Horticulture and Landscape Engineering, Institute of Horticulture, Slovak University of Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia;
- Department of Bioenergy, Food Technology and Microbiology, Institute of Food Technology and Nutrition, University of Rzeszow, 4 Zelwerowicza Str., 35-601 Rzeszow, Poland
| |
Collapse
|
9
|
Loera-Muro A, Ramírez-Castillo FY, Moreno-Flores AC, Martin EM, Avelar-González FJ, Guerrero-Barrera AL. Actinobacillus pleuropneumoniae Surviving on Environmental Multi-Species Biofilms in Swine Farms. Front Vet Sci 2021; 8:722683. [PMID: 34660763 PMCID: PMC8515031 DOI: 10.3389/fvets.2021.722683] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022] Open
Abstract
Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumonia, an important respiratory disease for the pig industry. A. pleuropneumoniae has traditionally been considered an obligate pig pathogen. However, its presence in the environment is starting to be known. Here, we report the A. pleuropneumoniae surviving in biofilms in samples of drinking water of swine farms from Mexico. Fourteen farms were studied. Twenty drinking water samples were positive to A. pleuropneumoniae distributed on three different farms. The bacteria in the drinking water samples showed the ability to form biofilms in vitro. Likewise, A. pleuropneumoniae biofilm formation in situ was observed on farm drinkers, where the biofilm formation was in the presence of other bacteria such as Escherichia coli, Stenotrophomonas maltophilia, and Acinetobacter schindleri. Our data suggest that A. pleuropneumoniae can inhabit aquatic environments using multi-species biofilms as a strategy to survive outside of their host.
Collapse
Affiliation(s)
- Abraham Loera-Muro
- CONACYT-Centro de Investigaciones Biológicas del Noreste, La Paz, Mexico
| | - Flor Y Ramírez-Castillo
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Mexico
| | - Adriana C Moreno-Flores
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Mexico
| | - Eduardo M Martin
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Mexico
| | - Francisco J Avelar-González
- Laboratorio de Estudios Ambientales, Departamento Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Mexico
| | - Alma L Guerrero-Barrera
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Mexico
| |
Collapse
|
10
|
Rodríguez Sartori D, Bertuola M, Miñán A, Gonik E, Gonzalez MC, Fernández Lorenzo de Mele M. Environmentally Induced Changes of Commercial Carbon Nanotubes in Aqueous Suspensions. Adaptive Behavior of Bacteria in Biofilms. ACS OMEGA 2021; 6:5197-5208. [PMID: 33681561 PMCID: PMC7931186 DOI: 10.1021/acsomega.0c05114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/31/2020] [Indexed: 06/12/2023]
Abstract
The effects of environmental factors such as sunlight irradiation and the presence of humic acid (HA) on the physicochemical properties of commercial multiwall carbon nanotubes (MWCNT) suspended in a simulated inorganic matrix (SIM) and their impacts on bacteria growing in biofilms were evaluated. Both solar irradiation and the presence of HA lead to the dissolution of adsorbed metals on the MWCNT, which are residues of synthesis catalysts. Also, preferential adsorption of certain HA components on the MWCNT induces important modifications in the aliphatic/aromatic relationship of HA components in solution and the generation and release of new moieties. Results demonstrated that the variation of such physicochemical parameters strongly affects the interactions of MWCNT with Pseudomonas aeruginosa sessile bacteria. Thus, the number of attached bacteria increased, and stress responses such as decrease in bacterial size were found in the presence of sunlight-irradiated MWCNT with a particular distribution of extracellular polymeric substances (EPS) strands. A shielding effect was observed when HA was added. It was concluded that physicochemical alterations caused by environmental conditions (with/without irradiation, presence/absence of HA) on MWCNT-containing SIM trigger distinctive adaptive behavior of bacteria in biofilms. This information must be taken into account in the development of biologically assisted treatments for organic metal co-contamination of MWCNT-containing media since MWCNT discharge alters the physicochemical properties and composition of the aqueous environment and the response of the biofilms that interact with it.
Collapse
Affiliation(s)
- Damián Rodríguez Sartori
- Instituto
de Investigaciones Fisicoquímicas Teóricas y Aplicadas
(INIFTA), CCT La Plata, CONICET, Facultad de Ciencias Exactas, UNLP, C.C. 16 Suc. 4, 1900 La Plata, Argentina
| | - Marcos Bertuola
- Instituto
de Investigaciones Fisicoquímicas Teóricas y Aplicadas
(INIFTA), CCT La Plata, CONICET, Facultad de Ciencias Exactas, UNLP, C.C. 16 Suc. 4, 1900 La Plata, Argentina
| | - Alejandro Miñán
- Instituto
de Investigaciones Fisicoquímicas Teóricas y Aplicadas
(INIFTA), CCT La Plata, CONICET, Facultad de Ciencias Exactas, UNLP, C.C. 16 Suc. 4, 1900 La Plata, Argentina
| | - Eduardo Gonik
- Instituto
de Investigaciones Fisicoquímicas Teóricas y Aplicadas
(INIFTA), CCT La Plata, CONICET, Facultad de Ciencias Exactas, UNLP, C.C. 16 Suc. 4, 1900 La Plata, Argentina
| | - Mónica C. Gonzalez
- Instituto
de Investigaciones Fisicoquímicas Teóricas y Aplicadas
(INIFTA), CCT La Plata, CONICET, Facultad de Ciencias Exactas, UNLP, C.C. 16 Suc. 4, 1900 La Plata, Argentina
| | - Mónica Fernández Lorenzo de Mele
- Instituto
de Investigaciones Fisicoquímicas Teóricas y Aplicadas
(INIFTA), CCT La Plata, CONICET, Facultad de Ciencias Exactas, UNLP, C.C. 16 Suc. 4, 1900 La Plata, Argentina
- Facultad
de Ingeniería, UNLP, B1900 La Plata, Argentina
| |
Collapse
|
11
|
Viruega-Góngora VI, Acatitla-Jácome IS, Reyes-Carmona SR, Baca BE, Ramírez-Mata A. Spatio-temporal formation of biofilms and extracellular matrix analysis in Azospirillum brasilense. FEMS Microbiol Lett 2021; 367:5762672. [PMID: 32105306 DOI: 10.1093/femsle/fnaa037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 02/25/2020] [Indexed: 01/02/2023] Open
Abstract
Elucidation of biofilm structure formation in the plant growth-promoting rhizobacterium Azospirillum brasilense is necessary to gain a better understanding of the growth of cells within the extracellular matrix and its role in the colonization of plants of agronomic importance. We used immunofluorescence microscopy and confocal laser scanning microscopy to study spatio-temporal biofilm formation on an abiotic surface. Observations facilitated by fluorescence microscopy revealed the presence of polar flagellin, exopolysaccharides, outer major membrane protein (OmaA) and extracellular DNA in the Azospirillum biofilm matrix. In static culture conditions, the polar flagellum disaggregated after 3 days of biofilm growth, but exopolysaccharides were increasing. These findings suggest that the first step in biofilm formation may be attachment, in which the bacterium first makes contact with a surface through its polar flagellum. After attaching to the surface, the long flagella and OmaA intertwine the cells to form a network. These bacterial aggregates initiate biofilm development. The underlying mechanisms dictating how the biofilm matrix components of A. brasilense direct the overall morphology of the biofilm are not well known. The methods developed here might be useful in further studies that analyze the differential spatial regulation of genes encoding matrix components that drive biofilm construction.
Collapse
Affiliation(s)
- Víctor I Viruega-Góngora
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla. Ciudad Universitaria Edif. IC11, Av. San Claudio S/N. Puebla Pue. México
| | - Iris S Acatitla-Jácome
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla. Ciudad Universitaria Edif. IC11, Av. San Claudio S/N. Puebla Pue. México
| | - Sandra R Reyes-Carmona
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla. Ciudad Universitaria Edif. IC11, Av. San Claudio S/N. Puebla Pue. México
| | - Beatriz E Baca
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla. Ciudad Universitaria Edif. IC11, Av. San Claudio S/N. Puebla Pue. México
| | - Alberto Ramírez-Mata
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla. Ciudad Universitaria Edif. IC11, Av. San Claudio S/N. Puebla Pue. México
| |
Collapse
|
12
|
Bischoff K, Sirantoine E, Wilson MEJ, George AD, Mendes Monteiro J, Saunders M. Spherulitic microbialites from modern hypersaline lakes, Rottnest Island, Western Australia. GEOBIOLOGY 2020; 18:725-741. [PMID: 32463178 DOI: 10.1111/gbi.12400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 04/08/2020] [Accepted: 04/26/2020] [Indexed: 06/11/2023]
Abstract
Fibrous-radiating carbonate spherulites spatially associated with poorly crystalline Mg-Si substances have formed within conical microbialites in modern hypersaline lakes on Rottnest Island, Western Australia. Two spherulitic fabrics can be distinguished based on compositional and textural differences. The oldest (lowermost) fabric comprises variably intergrown aragonitic spherulites 100-500 μm wide, containing micritic nuclei with coccoid cell molds in various stages of cell division. Spherulite matrices contain aggregates of individual nanospheres 150-200 nm wide, composed of a poorly crystalline Mg-Si phase, locally containing cell molds with similar dimensions to those within spherulite nuclei. The younger (upper) fabric comprises sub-polyhedral networks of mineralized EPS composed of an Mg-Si substance. The polyhedrons contain aragonite-replaced coccoid cells, voids, and polyhedral spherulites 8-12 μm wide with a morphology determined by fossil EPS, interpreted to have been produced by coccoid cyanobacteria. These spherulites are composed of high-Mg calcite, inferred to have formed in association with heterotrophic bacteria. Stable isotope data, textural relationships, and geochemical modeling are consistent with cyanobacterial oxygenic photosynthesis influencing the precipitation of Mg-Si substances and aragonitic spherulites by locally increasing the pH. The morphology of the polyhedral spherulites suggests the former presence of EPS and that faceted spherulites with similar dimensions in the geological record may represent biosignatures. The Rottnest Island conical microbialites demonstrate an intimate association between microbial features and processes and spherulitic fabrics, potentially providing insights into texturally and compositionally similar features in the geological record.
Collapse
Affiliation(s)
- Karl Bischoff
- School of Earth Sciences, The University of Western Australia, Perth, WA, Australia
| | - Eva Sirantoine
- School of Earth Sciences, The University of Western Australia, Perth, WA, Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
| | - Moyra E J Wilson
- School of Earth Sciences, The University of Western Australia, Perth, WA, Australia
| | - Annette D George
- School of Earth Sciences, The University of Western Australia, Perth, WA, Australia
| | - Juliana Mendes Monteiro
- School of Earth Sciences, The University of Western Australia, Perth, WA, Australia
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
| | - Martin Saunders
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
| |
Collapse
|
13
|
Characterization of Antimicrobial Effects of Plasma-Treated Water (PTW) Produced by Microwave-Induced Plasma (MidiPLexc) on Pseudomonas fluorescens Biofilms. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10093118] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For the decontamination of surfaces in the food production industry, plasma-generated compounds such as plasma-treated water or plasma-processed air offer many promising possibilities for future applications. Therefore, the antimicrobial effect of water treated with microwave-induced plasma (MidiPLexc) on Pseudomonas fluorescens biofilms was investigated. A total of 10 mL deionized water was treated with the MidiPLexc plasma source for 100, 300 and 900 s (pretreatment time) and the bacterial biofilms were exposed to the plasma-treated water for 1, 3 and 5 min (post-treatment time). To investigate the influence of plasma-treated water on P. fluorescens biofilms, microbiological assays (colony-forming units, fluorescence and XTT assay) and imaging techniques (fluorescence microscopy, confocal laser scanning microscopy, and atomic force microscopy) were used. The colony-forming units showed a maximum reduction of 6 log10 by using 300 s pretreated plasma water for 5 min. Additionally, a maximum reduction of 81% for the viability of the cells and a 92% reduction in the metabolic activity of the cells were achieved by using 900 s pretreated plasma water for 5 min. The microscopic images showed evident microbial inactivation within the biofilm even at the shortest pretreatment (100 s) and post-treatment (1 min) times. Moreover, reduction of the biofilm thickness and increased cluster formation within the biofilm was detected. Morphologically, the fusion of cell walls into a uniform dense cell mass was detectable. The findings correlated with a decrease in the pH value of the plasma-treated water, which forms the basis for the chemically active components of plasma-treated water and its antimicrobial effects. These results provide valuable insights into the mechanisms of inactivation of biofilms by plasma-generated compounds such as plasma-treated water and thus allow for further parameter adjustment for applications in food industry.
Collapse
|
14
|
Fulaz S, Hiebner D, Barros CHN, Devlin H, Vitale S, Quinn L, Casey E. Ratiometric Imaging of the in Situ pH Distribution of Biofilms by Use of Fluorescent Mesoporous Silica Nanosensors. ACS APPLIED MATERIALS & INTERFACES 2019; 11:32679-32688. [PMID: 31418546 DOI: 10.1021/acsami.9b09978] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Biofilms are communities of microorganisms enclosed in a self-generated matrix of extracellular polymeric substances. While biofilm recalcitrance and persistence are caused by several factors, a reduction in antimicrobial susceptibility has been closely associated with the generation of pH gradients within the biofilm structure. Cells embedded within the biofilm create a localized acidic microenvironment, which is unaffected by the external pH. Therefore, pH monitoring is a promising approach for understanding the complexities of a three-dimensional heterogeneous biofilm. A fluorescent pH nanosensor was designed through the synthesis of mesoporous silica nanoparticles (47 ± 5 nm diameter) conjugated to a pH-sensitive dye (fluorescein) and a pH-insensitive dye (rhodamine B) as an internal standard (dye-MSNs). The fluorescence intensity of fluorescein (IF) reduced significantly as the pH was decreased from 8.5 to 3.5. In contrast, the fluorescence intensity of rhodamine B (IR) remained constant at any pH. The ratio of IF/IR produced a sigmoidal curve with respect to the pH, in a working pH range between 4.5 and 7.5. Dye-MSNs enabled the measurement of pH gradients within Pseudomonas fluorescens WCS 365 biofilm microcolonies. The biofilms showed spatially distinct low-pH regions that were enclosed into large clusters corresponding to high-cell-density areas. Also present were small low-pH areas that spread indistinctly throughout the microcolony caused by the mass transfer effect. The lowest detected pH within the inner core of the microcolonies was 5.1, gradually increasing to a neutral pH toward the exterior of the microcolonies. The dye-MSNs were able to fully penetrate the biofilm matrix and allowed a quantitative ratiometric analysis of pH gradients and distribution throughout the biofilm, which was independent of the nanoparticle concentration.
Collapse
Affiliation(s)
- Stephanie Fulaz
- UCD School of Chemical and Bioprocess Engineering , University College Dublin , Belfield, Dublin 4 Dublin , Ireland
| | - Dishon Hiebner
- UCD School of Chemical and Bioprocess Engineering , University College Dublin , Belfield, Dublin 4 Dublin , Ireland
| | - Caio H N Barros
- UCD School of Chemical and Bioprocess Engineering , University College Dublin , Belfield, Dublin 4 Dublin , Ireland
| | - Henry Devlin
- UCD School of Chemical and Bioprocess Engineering , University College Dublin , Belfield, Dublin 4 Dublin , Ireland
| | - Stefania Vitale
- UCD School of Chemical and Bioprocess Engineering , University College Dublin , Belfield, Dublin 4 Dublin , Ireland
| | - Laura Quinn
- UCD School of Chemical and Bioprocess Engineering , University College Dublin , Belfield, Dublin 4 Dublin , Ireland
| | - Eoin Casey
- UCD School of Chemical and Bioprocess Engineering , University College Dublin , Belfield, Dublin 4 Dublin , Ireland
| |
Collapse
|
15
|
Lauer Cruz K, de Souza da Motta A. Characterization of biofilm production by Pseudomonas fluorescens isolated from refrigerated raw buffalo milk. Journal of Food Science and Technology 2019; 56:4595-4604. [PMID: 31686691 DOI: 10.1007/s13197-019-03924-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 06/28/2019] [Accepted: 07/03/2019] [Indexed: 12/13/2022]
Abstract
Pseudomonas fluorescens can often be isolated from refrigerated raw milk. Two strains of P. fluorescens PL5.4 and PL7.1, isolated from raw buffalo milk, were evaluated for their proteolytic capacity, exopolysaccharide production and biofilm production. Proteolytic activity was observed in both strains. The P. fluorescens PL5.4 strain presented fluorescence in the presence of calcofluor, indicating exopolysaccharide production. Both strains were able to produce biofilm at 7 °C for 72 h. For the biofilm production test on stainless steel, adherent cell counts of up to 7.1, 7.3 and 8.8 log CFU/cm2 at 7, 23 and 30 °C were obtained. Through scanning electron microscopy, it was possible to observe the biofilm produced by the P. fluorescens PL5.4 strain. Proper cleaning and disinfection practices in order are important to reduce bacterial contamination and extend the useful life of raw material and its derivatives.
Collapse
Affiliation(s)
- Karine Lauer Cruz
- Instituto de Ciências Básicas da Saúde, Microbiology Department, Immunology and Parasitology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Sala 216, Porto Alegre, 90050-170 Brazil
| | - Amanda de Souza da Motta
- Instituto de Ciências Básicas da Saúde, Microbiology Department, Immunology and Parasitology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Sala 216, Porto Alegre, 90050-170 Brazil
| |
Collapse
|
16
|
Abriat C, Virgilio N, Heuzey MC, Daigle F. Microbiological and real-time mechanical analysis of Bacillus licheniformis and Pseudomonas fluorescens dual-species biofilm. Microbiology (Reading) 2019; 165:747-756. [DOI: 10.1099/mic.0.000819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Clemence Abriat
- Department of Chemical Engineering, Polytechnique Montréal, CREPEC, Montréal, Québec, Canada
- Department of Microbiology, Infection and Immunology, Université de Montréal, Montréal, Québec, Canada
| | - Nick Virgilio
- Department of Chemical Engineering, Polytechnique Montréal, CREPEC, Montréal, Québec, Canada
| | - Marie-Claude Heuzey
- Department of Chemical Engineering, Polytechnique Montréal, CREPEC, Montréal, Québec, Canada
| | - France Daigle
- Department of Microbiology, Infection and Immunology, Université de Montréal, Montréal, Québec, Canada
| |
Collapse
|
17
|
Singh AK, Yadav S, Chauhan BS, Nandy N, Singh R, Neogi K, Roy JK, Srikrishna S, Singh RK, Prakash P. Classification of Clinical Isolates of Klebsiella pneumoniae Based on Their in vitro Biofilm Forming Capabilities and Elucidation of the Biofilm Matrix Chemistry With Special Reference to the Protein Content. Front Microbiol 2019; 10:669. [PMID: 31019496 PMCID: PMC6458294 DOI: 10.3389/fmicb.2019.00669] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 03/18/2019] [Indexed: 12/13/2022] Open
Abstract
Klebsiella pneumoniae is a human pathogen, capable of forming biofilms on abiotic and biotic surfaces. The limitations of the therapeutic options against Klebsiella pneumoniae is actually due to its innate capabilities to form biofilm and harboring determinants of multidrug resistance. We utilized a newer approach for classification of biofilm producing Klebsiella pneumoniae isolates and subsequently we evaluated the chemistry of its slime, more accurately its biofilm. We extracted and determined the amount of polysaccharides and proteins from representative bacterial biofilms. The spatial distribution of sugars and proteins were then investigated in the biofilm matrix using confocal laser scanning microscopy (CLSM). Thereafter, the extracted matrix components were subjected to sophisticated analysis incorporating Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, one-dimensional gel-based electrophoresis (SDS-PAGE), high performance liquid chromatography (HPLC), and MALDI MS/MS analysis. Besides, the quantification of its total proteins, total sugars, uronates, total acetyl content was also done. Results suggest sugars are not the only/major constituent of its biofilms. The proteins were harvested and subjected to SDS-PAGE which revealed various common and unique protein bands. The common band was excised and analyzed by HPLC. MALDI MS/MS results of this common protein band indicated the presence of different proteins within the biofilm. The 55 different proteins were identified including both cytosolic and membrane proteins. About 22 proteins were related to protein synthesis and processing while 15 proteins were identified related to virulence. Similarly, proteins related to energy and metabolism were 8 and those related to capsule and cell wall synthesis were 4. These results will improve our understanding of Klebsiella biofilm composition and will further help us design better strategies for controlling its biofilm such as techniques focused on weakening/targeting certain portions of the slime which is the most common building block of the biofilm matrix.
Collapse
Affiliation(s)
- Ashish Kumar Singh
- Bacterial Biofilm and Drug Resistance Research Laboratory, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
- Molecular Immunology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Shivangi Yadav
- Bacterial Biofilm and Drug Resistance Research Laboratory, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Brijesh Singh Chauhan
- Cell and Neurobiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Nabarun Nandy
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Rajan Singh
- Molecular Immunology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Kaushik Neogi
- Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanasi, India
| | - Jagat Kumar Roy
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Saripella Srikrishna
- Cell and Neurobiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Rakesh Kumar Singh
- Molecular Immunology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Pradyot Prakash
- Bacterial Biofilm and Drug Resistance Research Laboratory, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| |
Collapse
|
18
|
Martínez-Hidalgo P, Maymon M, Pule-Meulenberg F, Hirsch AM. Engineering root microbiomes for healthier crops and soils using beneficial, environmentally safe bacteria. Can J Microbiol 2019; 65:91-104. [DOI: 10.1139/cjm-2018-0315] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Green Revolution developed new crop varieties, which greatly improved food security worldwide. However, the growth of these plants relied heavily on chemical fertilizers and pesticides, which have led to an overuse of synthetic fertilizers, insecticides, and herbicides with serious environmental consequences and negative effects on human health. Environmentally friendly plant-growth-promoting methods to replace our current reliance on synthetic chemicals and to develop more sustainable agricultural practices to offset the damage caused by many agrochemicals are proposed herein. The increased use of bioinoculants, which consist of microorganisms that establish synergies with target crops and influence production and yield by enhancing plant growth, controlling disease, and providing critical mineral nutrients, is a potential solution. The microorganisms found in bioinoculants are often bacteria or fungi that reside within either external or internal plant microbiomes. However, before they can be used routinely in agriculture, these microbes must be confirmed as nonpathogenic strains that promote plant growth and survival. In this article, besides describing approaches for discovering plant-growth-promoting bacteria in various environments, including phytomicrobiomes and soils, we also discuss methods to evaluate their safety for the environment and for human health.
Collapse
Affiliation(s)
- Pilar Martínez-Hidalgo
- Departamento de Microbiología y Genética, Universidad de Salamanca, Spain
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
| | - Maskit Maymon
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
| | - Flora Pule-Meulenberg
- Department of Crop Science and Production, Botswana University of Agriculture and Natural Resources, Private Bag 0027, A1 Sebele Content Farm, Gaborone, Botswana
| | - Ann M. Hirsch
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA
| |
Collapse
|
19
|
Anjum A, Chung PY, Ng SF. PLGA/xylitol nanoparticles enhance antibiofilm activity via penetration into biofilm extracellular polymeric substances. RSC Adv 2019; 9:14198-14208. [PMID: 35519311 PMCID: PMC9064039 DOI: 10.1039/c9ra00125e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/24/2019] [Indexed: 11/21/2022] Open
Abstract
Biofilms are gelatinous masses of microorganisms attached to wound surfaces.
Collapse
Affiliation(s)
- Anam Anjum
- Centre for Drug Delivery Research
- Faculty of Pharmacy
- University Kebangsaan Malaysia
- Kuala Lumpur
- Malaysia
| | - Pooi-Yin Chung
- Department of Microbiology
- International Medical University
- Kuala Lumpur
- Malaysia
| | - Shiow-Fern Ng
- Centre for Drug Delivery Research
- Faculty of Pharmacy
- University Kebangsaan Malaysia
- Kuala Lumpur
- Malaysia
| |
Collapse
|
20
|
Wilson C, Lukowicz R, Merchant S, Valquier-Flynn H, Caballero J, Sandoval J, Okuom M, Huber C, Brooks TD, Wilson E, Clement B, Wentworth CD, Holmes AE. Quantitative and Qualitative Assessment Methods for Biofilm Growth: A Mini-review. RESEARCH & REVIEWS. JOURNAL OF ENGINEERING AND TECHNOLOGY 2017; 6:http://www.rroij.com/open-access/quantitative-and-qualitative-assessment-methods-for-biofilm-growth-a-minireview-.pdf. [PMID: 30214915 PMCID: PMC6133255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Biofilms are microbial communities attached to a surface and embedded in an extracellular polymeric substance which provides for the protection, stability and nutrients of the various bacterial species indwelling. These communities can build up in a variety of different environments from industrial equipment to medical devices resulting in damage, loss of productivity and disease. They also have great potential for economic and societal benefits as bioremediation agents and renewable energy sources. The great potential benefits and threats of biofilms has encouraged researchers across disciplines to study biofilm characteristics and antibiofilm strategies resulting in chemists, physicists, material scientists, and engineers, to develop beneficial biofilm applications and prevention methods. The ultimate outcome is a wealth of knowledge and innovative technology. However, without extensive formal training in microbes and biofilm research, these scientists find a daunting array of established techniques for growing, quantifying and characterizing biofilms while trying to design experiments and develop innovative laboratory protocols. This mini-review focuses on enriching interdisciplinary efforts and understanding by overviewing a variety of quantitative and qualitative biofilm characterization methods to assist the novice researcher in assay selection. This review consists of four parts. Part 1 is a brief overview of biofilms and the unique properties that demand a highly interdisciplinary approach. Part 2 describes the classical quantification techniques including colony forming unit (CFU) counting and crystal violet staining, but also introduces some modern methods including ATP bioluminescence and quartz crystal microbalance. Part 3 focuses on the characterization of biofilm morphology and chemistry including scanning electron microscopy and spectroscopic methods. Finally, Part 4 illustrates the use of software, including ImageJ and predictive modeling platforms, for biofilm analysis. Each section highlights the most common methods, including literature references, to help novice biofilm researchers make choices which commensurate with their study goals, budget and available equipment.
Collapse
Affiliation(s)
- Christina Wilson
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Rachel Lukowicz
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Stefan Merchant
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Helena Valquier-Flynn
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Jeniffer Caballero
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Jasmin Sandoval
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Macduff Okuom
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Christopher Huber
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Tessa Durham Brooks
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | - Erin Wilson
- Department of Chemistry, Westminster College, New Wilmington, Pennsylvania
| | - Barbara Clement
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| | | | - Andrea E Holmes
- Department of Chemistry, Biology, Physics & Engineering, Doane University, Crete, Nebraska
| |
Collapse
|
21
|
VILA T, FONSECA B, DA CUNHA M, DOS SANTOS G, ISHIDA K, BARRETO-BERGTER E, DE SOUZA W, ROZENTAL S. Candida albicansbiofilms: comparative analysis of room-temperature and cryofixation for scanning electron microscopy. J Microsc 2017; 267:409-419. [DOI: 10.1111/jmi.12580] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 04/25/2017] [Accepted: 04/26/2017] [Indexed: 12/16/2022]
Affiliation(s)
- T. VILA
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - B.B. FONSECA
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - M.M.L. DA CUNHA
- Núcleo Multidisciplinar de Pesquisa em Biologia UFRJ-Xerém-NUMPEX-BIO; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - G.R.C. DOS SANTOS
- Instituto de Bioquímica Médica; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - K. ISHIDA
- Instituto de Ciências Biomédicas; Universidade de São Paulo; São Paulo Brasil
| | - E. BARRETO-BERGTER
- Instituto de Microbiologia Prof. Paulo de Góes; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - W. DE SOUZA
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| | - S. ROZENTAL
- Instituto de Biofísica Carlos Chagas Filho; Universidade Federal do Rio de Janeiro; Rio de Janeiro Brasil
| |
Collapse
|
22
|
Araújo PA, Machado I, Meireles A, Leiknes T, Mergulhão F, Melo LF, Simões M. Combination of selected enzymes with cetyltrimethylammonium bromide in biofilm inactivation, removal and regrowth. Food Res Int 2017; 95:101-107. [DOI: 10.1016/j.foodres.2017.02.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 02/20/2017] [Accepted: 02/26/2017] [Indexed: 11/25/2022]
|
23
|
Tallawi M, Opitz M, Lieleg O. Modulation of the mechanical properties of bacterial biofilms in response to environmental challenges. Biomater Sci 2017; 5:887-900. [DOI: 10.1039/c6bm00832a] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In this review, we highlight recent research on the relationship between biofilm matrix composition, biofilm mechanics and environmental stimuli.
Collapse
Affiliation(s)
- Marwa Tallawi
- Department of Mechanical Engineering and Munich School of Bioengineering
- Technische Universität München
- Garching
- Germany
| | - Madeleine Opitz
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - Oliver Lieleg
- Department of Mechanical Engineering and Munich School of Bioengineering
- Technische Universität München
- Garching
- Germany
| |
Collapse
|
24
|
Exopolysaccharide microchannels direct bacterial motility and organize multicellular behavior. ISME JOURNAL 2016; 10:2620-2632. [PMID: 27152937 PMCID: PMC5113850 DOI: 10.1038/ismej.2016.60] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 02/22/2016] [Accepted: 03/01/2016] [Indexed: 11/16/2022]
Abstract
The myxobacteria are a family of soil bacteria that form biofilms of complex architecture, aligned multilayered swarms or fruiting body structures that are simple or branched aggregates containing myxospores. Here, we examined the structural role of matrix exopolysaccharide (EPS) in the organization of these surface-dwelling bacterial cells. Using time-lapse light and fluorescence microscopy, as well as transmission electron microscopy and focused ion beam/scanning electron microscopy (FIB/SEM) electron microscopy, we found that Myxococcus xanthus cell organization in biofilms is dependent on the formation of EPS microchannels. Cells are highly organized within the three-dimensional structure of EPS microchannels that are required for cell alignment and advancement on surfaces. Mutants lacking EPS showed a lack of cell orientation and poor colony migration. Purified, cell-free EPS retains a channel-like structure, and can complement EPS− mutant motility defects. In addition, EPS provides the cooperative structure for fruiting body formation in both the simple mounds of M. xanthus and the complex, tree-like structures of Chondromyces crocatus. We furthermore investigated the possibility that EPS impacts community structure as a shared resource facilitating cooperative migration among closely related isolates of M. xanthus.
Collapse
|
25
|
Gunawardana M, Hyde ER, Lahmeyer S, Dorsey BL, La Val TP, Mullen M, Yoo J, Knight R, Baum MM. Euphorbia plant latex is inhabited by diverse microbial communities. AMERICAN JOURNAL OF BOTANY 2015; 102:1966-1977. [PMID: 26656131 DOI: 10.3732/ajb.1500223] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 10/12/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY The antimicrobial properties and toxicity of Euphorbia plant latex should make it a hostile environment to microbes. However, when specimens from Euphorbia spp. were propagated in tissue culture, microbial growth was observed routinely, raising the question whether the latex of this diverse plant genus can be a niche for polymicrobial communities. METHODS Latex from a phylogenetically diverse set of Euphorbia species was collected and genomic microbial DNA extracted. Deep sequencing of bar-coded amplicons from taxonomically informative gene fragments was used to measure bacterial and fungal species richness, evenness, and composition. KEY RESULTS Euphorbia latex was found to contain unexpectedly complex bacterial (mean: 44.0 species per sample; 9 plants analyzed) and fungal (mean: 20.9 species per sample; 22 plants analyzed) communities using culture-independent methods. Many of the identified taxa are known plant endophytes, but have not been previously found in latex. CONCLUSIONS Our results suggest that Euphorbia plant latex, a putatively hostile antimicrobial environment, unexpectedly supports diverse bacterial and fungal communities. The ecological roles of these microorganisms and potential interactions with their host plants are unknown and warrant further research.
Collapse
Affiliation(s)
- Manjula Gunawardana
- Department of Chemistry, Oak Crest Institute of Science, 128-132 W. Chestnut Ave., Monrovia, California 91016 USA
| | - Embriette R Hyde
- BioFrontiers Institute, the University of Colorado at Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 USA; present address: Department of Pediatrics, the University of California at San Diego, 9600 Gilman Drive, La Jolla, California 92093 USA
| | - Sean Lahmeyer
- The Huntington Library, Art Collections, and Botanical Gardens, 1151 Oxford Road, San Marino, California 91108 USA
| | - Brian L Dorsey
- The Huntington Library, Art Collections, and Botanical Gardens, 1151 Oxford Road, San Marino, California 91108 USA
| | - Taylor P La Val
- Department of Chemistry, Oak Crest Institute of Science, 128-132 W. Chestnut Ave., Monrovia, California 91016 USA
| | - Madeline Mullen
- Department of Chemistry, Oak Crest Institute of Science, 128-132 W. Chestnut Ave., Monrovia, California 91016 USA
| | - Jennifer Yoo
- Department of Chemistry, Oak Crest Institute of Science, 128-132 W. Chestnut Ave., Monrovia, California 91016 USA
| | - Rob Knight
- BioFrontiers Institute, the University of Colorado at Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 USA; present address: Department of Pediatrics, the University of California at San Diego, 9600 Gilman Drive, La Jolla, California 92093 USA Departments of Chemistry and Biochemistry and Computer Science, the University of Colorado at Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 USA; present address: Departments of Pediatrics and Computer Science and Engineering, the University of California at San Diego, 9600 Gilman Drive, La Jolla, California 92093 USA
| | - Marc M Baum
- Department of Chemistry, Oak Crest Institute of Science, 128-132 W. Chestnut Ave., Monrovia, California 91016 USA
| |
Collapse
|
26
|
Microbiology, genomics, and clinical significance of the Pseudomonas fluorescens species complex, an unappreciated colonizer of humans. Clin Microbiol Rev 2015; 27:927-48. [PMID: 25278578 DOI: 10.1128/cmr.00044-14] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Pseudomonas fluorescens is not generally considered a bacterial pathogen in humans; however, multiple culture-based and culture-independent studies have identified it at low levels in the indigenous microbiota of various body sites. With recent advances in comparative genomics, many isolates originally identified as the "species" P. fluorescens are now being reclassified as novel Pseudomonas species within the P. fluorescens "species complex." Although most widely studied for its role in the soil and the rhizosphere, P. fluorescens possesses a number of functional traits that provide it with the capability to grow and thrive in mammalian hosts. While significantly less virulent than P. aeruginosa, P. fluorescens can cause bacteremia in humans, with most reported cases being attributable either to transfusion of contaminated blood products or to use of contaminated equipment associated with intravenous infusions. Although not suspected of being an etiologic agent of pulmonary disease, there are a number of reports identifying it in respiratory samples. There is also an intriguing association between P. fluorescens and human disease, in that approximately 50% of Crohn's disease patients develop serum antibodies to P. fluorescens. Altogether, these reports are beginning to highlight a far more common, intriguing, and potentially complex association between humans and P. fluorescens during health and disease.
Collapse
|
27
|
Soil and Waste Matrix Affects Spatial Heterogeneity of Bacteria Filtration during Unsaturated Flow. WATER 2015. [DOI: 10.3390/w7030836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
28
|
Nelson EM, Mirsaidov U, Sarveswaran K, Perry N, Kurz V, Timp W, Timp G. Ecology of a Simple Synthetic Biofilm. THE PHYSICAL BASIS OF BACTERIAL QUORUM COMMUNICATION 2015. [DOI: 10.1007/978-1-4939-1402-9_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
29
|
Luo J, Zhang J, Tan X, McDougald D, Zhuang G, Fane AG, Kjelleberg S, Cohen Y, Rice SA. The correlation between biofilm biopolymer composition and membrane fouling in submerged membrane bioreactors. BIOFOULING 2014; 30:1093-1110. [PMID: 25367774 DOI: 10.1080/08927014.2014.971238] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Biofouling, the combined effect of microorganism and biopolymer accumulation, significantly reduces the process efficiency of membrane bioreactors (MBRs). Here, four biofilm components, alpha-polysaccharides, beta-polysaccharides, proteins and microorganisms, were quantified in MBRs. The biomass of each component was positively correlated with the transmembrane pressure increase in MBRs. Proteins were the most abundant biopolymer in biofilms and showed the fastest rate of increase. The spatial distribution and co-localization analysis of the biofouling components indicated at least 60% of the extracellular polysaccharide (EPS) components were associated with the microbial cells when the transmembrane pressure (TMP) entered the jump phase, suggesting that the EPS components were either secreted by the biofilm cells or that the deposition of these components facilitated biofilm formation. It is suggested that biofilm formation and the accumulation of EPS are intrinsically coupled, resulting in biofouling and loss of system performance. Therefore, strategies that control biofilm formation on membranes may result in a significant improvement of MBR performance.
Collapse
Affiliation(s)
- Jinxue Luo
- a Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Wu S, Baum MM, Kerwin J, Guerrero D, Webster S, Schaudinn C, VanderVelde D, Webster P. Biofilm-specific extracellular matrix proteins of nontypeable Haemophilus influenzae. Pathog Dis 2014; 72:143-60. [PMID: 24942343 DOI: 10.1111/2049-632x.12195] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/07/2014] [Accepted: 06/11/2014] [Indexed: 11/28/2022] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi), a human respiratory tract pathogen, can form colony biofilms in vitro. Bacterial cells and the amorphous extracellular matrix (ECM) constituting the biofilm can be separated using sonication. The ECM from 24- and 96-h NTHi biofilms contained polysaccharides and proteinaceous components as detected by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) spectroscopy. More conventional chemical assays on the biofilm ECM confirmed the presence of these components and also DNA. Proteomics revealed eighteen proteins present in biofilm ECM that were not detected in planktonic bacteria. One ECM protein was unique to 24-h biofilms, two were found only in 96-h biofilms, and fifteen were present in the ECM of both 24- and 96-h NTHi biofilms. All proteins identified were either associated with bacterial membranes or cytoplasmic proteins. Immunocytochemistry showed two of the identified proteins, a DNA-directed RNA polymerase and the outer membrane protein OMP P2, associated with bacteria and biofilm ECM. Identification of biofilm-specific proteins present in immature biofilms is an important step in understanding the in vitro process of NTHi biofilm formation. The presence of a cytoplasmic protein and a membrane protein in the biofilm ECM of immature NTHi biofilms suggests that bacterial cell lysis may be a feature of early biofilm formation.
Collapse
Affiliation(s)
- Siva Wu
- Bioenergy/GTL & Structural Biology Department, Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Wu S, Li X, Gunawardana M, Maguire K, Guerrero-Given D, Schaudinn C, Wang C, Baum MM, Webster P. Beta- lactam antibiotics stimulate biofilm formation in non-typeable haemophilus influenzae by up-regulating carbohydrate metabolism. PLoS One 2014; 9:e99204. [PMID: 25007395 PMCID: PMC4090067 DOI: 10.1371/journal.pone.0099204] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 05/12/2014] [Indexed: 12/31/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10 µg/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended.
Collapse
Affiliation(s)
- Siva Wu
- Life Sciences Division, University of California, Berkeley, California, United States of America
| | - Xiaojin Li
- Molecular Diagnostic Laboratory, ApolloGen Inc., Irvine, California, United States of America
| | - Manjula Gunawardana
- Oak Crest Institute of Science, Pasadena, California, United States of America
| | - Kathleen Maguire
- University of California San Diego, San Diego, California, United States of America
| | | | | | - Charles Wang
- Center for Genomics and Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Marc M. Baum
- Oak Crest Institute of Science, Pasadena, California, United States of America
| | - Paul Webster
- Oak Crest Institute of Science, Pasadena, California, United States of America
- Center for Electron Microscopy and Microanalysis, University of Southern California, Los Angeles, California, United States of America
| |
Collapse
|
32
|
Death and transfiguration in static Staphylococcus epidermidis cultures. PLoS One 2014; 9:e100002. [PMID: 24964210 PMCID: PMC4070908 DOI: 10.1371/journal.pone.0100002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/19/2014] [Indexed: 12/13/2022] Open
Abstract
The overwhelming majority of bacteria live in slime embedded microbial communities termed biofilms, which are typically adherent to a surface. However, when several Staphylococcus epidermidis strains were cultivated in static liquid cultures, macroscopic aggregates were seen floating within the broth and also sedimented at the test tube bottom. Light- and electron microscopy revealed that early-stage aggregates consisted of bacteria and extracellular matrix, organized in sheet-like structures. Perpendicular under the sheets hung a network of periodically arranged, bacteria-associated strands. During the extended cultivation, the strands of a subpopulation of aggregates developed into cross-connected wall-like structures, in which aligned bacteria formed the walls. The resulting architecture had a compartmentalized appearance. In late-stage cultures, the wall-associated bacteria disintegrated so that, henceforth, the walls were made of the coalescing remnants of lysed bacteria, while the compartment-like organization remained intact. At the same time, the majority of strand-containing aggregates with associated culturable bacteria continued to exist. These observations indicate that some strains of Staphylococcus epidermidis are able to build highly sophisticated structures, in which a subpopulation undergoes cell lysis, presumably to provide continued access to nutrients in a nutrient-limited environment, whilst maintaining structural integrity.
Collapse
|
33
|
Fazli M, Almblad H, Rybtke ML, Givskov M, Eberl L, Tolker-Nielsen T. Regulation of biofilm formation in Pseudomonas and Burkholderia species. Environ Microbiol 2014; 16:1961-81. [PMID: 24592823 DOI: 10.1111/1462-2920.12448] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/12/2014] [Accepted: 02/28/2014] [Indexed: 01/28/2023]
Abstract
In the present review, we describe and compare the molecular mechanisms that are involved in the regulation of biofilm formation by Pseudomonas putida, Pseudomonas fluorescens, Pseudomonas aeruginosa and Burkholderia cenocepacia. Our current knowledge suggests that biofilm formation is regulated by cyclic diguanosine-5'-monophosphate (c-di-GMP), small RNAs (sRNA) and quorum sensing (QS) in all these bacterial species. The systems that employ c-di-GMP as a second messenger regulate the production of exopolysaccharides and surface proteins which function as extracellular matrix components in the biofilms formed by the bacteria. The systems that make use of sRNAs appear to regulate the production of exopolysaccharide biofilm matrix material in all these species. In the pseudomonads, QS regulates the production of extracellular DNA, lectins and biosurfactants which all play a role in biofilm formation. In B.cenocepacia QS regulates the expression of a large surface protein, lectins and extracellular DNA that all function as biofilm matrix components. Although the three regulatory systems all regulate the production of factors used for biofilm formation, the molecular mechanisms involved in transducing the signals into expression of the biofilm matrix components differ between the species. Under the conditions tested, exopolysaccharides appears to be the most important biofilm matrix components for P.aeruginosa, whereas large surface proteins appear to be the most important biofilm matrix components for P.putida, P.fluorescens, and B.cenocepacia.
Collapse
Affiliation(s)
- Mustafa Fazli
- Department of International Health, Immunology, and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark; Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Istanbul, Turkey
| | | | | | | | | | | |
Collapse
|
34
|
Sustained delivery of commensal bacteria from pod-intravaginal rings. Antimicrob Agents Chemother 2014; 58:2262-7. [PMID: 24492360 DOI: 10.1128/aac.02542-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Topical administration of live commensal bacteria to the vaginal tract holds significant potential as a cost-effective strategy for the treatment of sexually transmitted infections and the delivery of mucosal vaccines. Probiotic-releasing intravaginal rings (IVRs) embody significant theoretical advantages over traditional daily-dosage forms, such as sustained and controlled delivery leading to improved adherence to therapy compared to that of frequent dosing. The conventional IVR designs, however, are not amenable to the delivery of live bacteria. We have developed a novel pod-IVR technology where polymer-coated tablets ("pods") of Lactobacillus gasseri strain ATCC 33323, a commensal microorganism of human origin, are embedded in silicone IVRs. The release rate of bacterial cells is controlled by the diameter of a delivery channel that exposes a portion of the pod to external fluids. In vitro studies demonstrated that the prototype devices released between 1.1×10(7) and 14×10(7) cells per day for up to 21 days in a controlled sustained fashion with stable burst-free release kinetics. The daily release rates were correlated with the cross-sectional area of the delivery channel. Bacteria in the IVR pods remained viable throughout the in vitro studies and formed biofilms on the surfaces of the devices. This proof-of-principle study represents the first demonstration of a prolonged, sustained release of bacteria from an intravaginal device and warrants further investigation of this device as a nonchemotherapeutic agent for the restoration and maintenance of normal urogenital flora.
Collapse
|
35
|
Mangwani N, Shukla SK, Rao TS, Das S. Calcium-mediated modulation of Pseudomonas mendocina NR802 biofilm influences the phenanthrene degradation. Colloids Surf B Biointerfaces 2014; 114:301-9. [DOI: 10.1016/j.colsurfb.2013.10.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 10/01/2013] [Accepted: 10/02/2013] [Indexed: 12/31/2022]
|
36
|
Eller MR, Vidigal PMP, Salgado RL, Alves MP, Dias RS, da Silva CC, de Carvalho AF, Kropinski A, De Paula SO. UFV-P2 as a member of the Luz24likevirus genus: a new overview on comparative functional genome analyses of the LUZ24-like phages. BMC Genomics 2014; 15:7. [PMID: 24384011 PMCID: PMC3890496 DOI: 10.1186/1471-2164-15-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 12/26/2013] [Indexed: 11/26/2022] Open
Abstract
Background Phages infecting spoilage microorganisms have been considered as alternative biocontrol agents, and the study of their genomes is essential to their safe use in foods. UFV-P2 is a new Pseudomonas fluorescens-specific phage that has been tested for its ability to inhibit milk proteolysis. Results The genome of the phage UFV-P2 is composed of bidirectional modules and presented 75 functionally predict ORFs, forming clusters of early and late transcription. Further genomic comparisons of Pseudomonas-specific phages showed that these viruses could be classified according to conserved segments that appear be free from genome rearrangements, called locally collinear blocks (LCBs). In addition, the genome organization of the phage UFV-P2 was shown to be similar to that of phages PaP3 and LUZ24 which have recently been classified as a Luz24likevirus. Conclusions We have presented the functional annotation of UFV-P2, a new Pseudomonas fluorescens phage. Based on structural genomic comparison and phylogenetic clustering, we suggest the classification of UFV-P2 in the Luz24likevirus genus, and present a set of shared locally collinear blocks as the genomic signature for this genus.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Sérgio O De Paula
- Laboratory of Molecular Immunovirology, Federal University of Viçosa, Av, PH Rolfs, s/n, Campus da UFV, Viçosa, Minas Gerais 36570-000, Brazil.
| |
Collapse
|
37
|
Oates A, Bowling FL, Boulton AJM, Bowler PG, Metcalf DG, McBain AJ. The visualization of biofilms in chronic diabetic foot wounds using routine diagnostic microscopy methods. J Diabetes Res 2014; 2014:153586. [PMID: 24839608 PMCID: PMC4009286 DOI: 10.1155/2014/153586] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Accepted: 02/14/2014] [Indexed: 12/31/2022] Open
Abstract
Diabetic foot wounds are commonly colonised by taxonomically diverse microbial communities and may additionally be infected with specific pathogens. Since biofilms are demonstrably less susceptible to antimicrobial agents than are planktonic bacteria, and may be present in chronic wounds, there is increasing interest in their aetiological role. In the current investigation, the presence of structured microbial assemblages in chronic diabetic foot wounds is demonstrated using several visualization methods. Debridement samples, collected from the foot wounds of diabetic patients, were histologically sectioned and examined using bright-field, fluorescence, and environmental scanning electron microscopy and assessed by quantitative differential viable counting. All samples (n = 26) harboured bioburdens in excess of 5 log₁₀ CFU/g. Microcolonies were identified in 4/4 samples by all three microscopy methods, although bright-field and fluorescence microscopy were more effective at highlighting putative biofilm morphology than ESEM. Results in this pilot study indicate that bacterial microcolonies and putative biofilm matrix can be visualized in chronic wounds using fluorescence microscopy and ESEM, but also using the simple Gram stain.
Collapse
Affiliation(s)
- Angela Oates
- Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Frank L. Bowling
- Department of Medicine Manchester Royal Infirmary, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Andrew J. M. Boulton
- Department of Medicine Manchester Royal Infirmary, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | | | | | - Andrew J. McBain
- Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
- *Andrew J. McBain:
| |
Collapse
|
38
|
Baum MM, Gunawardana M, Webster P. Experimental approaches to investigating the vaginal biofilm microbiome. Methods Mol Biol 2014; 1147:85-103. [PMID: 24664828 PMCID: PMC8801157 DOI: 10.1007/978-1-4939-0467-9_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Unraveling the complex ecology of the vaginal biofilm microbiome relies on a number of complementary techniques. Here, we describe the experimental approaches for studying vaginal microbial biofilm samples with a focus on specimen preparation for subsequent analysis. The techniques include fluorescence microscopy, fluorescence in situ hybridization, and scanning and transmission electron microscopy. Isolation of microbial DNA and RNA from these samples is covered along with a brief discussion of chemical analysis methods.
Collapse
Affiliation(s)
- Marc M Baum
- Department of Chemistry, Oak Crest Institute of Science, 2275 E Foothill Boulevard, Pasadena, CA, 91107, USA,
| | | | | |
Collapse
|
39
|
Hödl I, Mari L, Bertuzzo E, Suweis S, Besemer K, Rinaldo A, Battin TJ. Biophysical controls on cluster dynamics and architectural differentiation of microbial biofilms in contrasting flow environments. Environ Microbiol 2013; 16:802-12. [PMID: 23879839 PMCID: PMC4231231 DOI: 10.1111/1462-2920.12205] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/16/2013] [Accepted: 06/17/2013] [Indexed: 11/28/2022]
Abstract
Ecology, with a traditional focus on plants and animals, seeks to understand the mechanisms underlying structure and dynamics of communities. In microbial ecology, the focus is changing from planktonic communities to attached biofilms that dominate microbial life in numerous systems. Therefore, interest in the structure and function of biofilms is on the rise. Biofilms can form reproducible physical structures (i.e. architecture) at the millimetre-scale, which are central to their functioning. However, the spatial dynamics of the clusters conferring physical structure to biofilms remains often elusive. By experimenting with complex microbial communities forming biofilms in contrasting hydrodynamic microenvironments in stream mesocosms, we show that morphogenesis results in ‘ripple-like’ and ‘star-like’ architectures – as they have also been reported from monospecies bacterial biofilms, for instance. To explore the potential contribution of demographic processes to these architectures, we propose a size-structured population model to simulate the dynamics of biofilm growth and cluster size distribution. Our findings establish that basic physical and demographic processes are key forces that shape apparently universal biofilm architectures as they occur in diverse microbial but also in single-species bacterial biofilms.
Collapse
Affiliation(s)
- Iris Hödl
- Department of Limnology and Oceanography, Faculty of Life Sciences, University of Vienna, 1090, Vienna, Austria
| | | | | | | | | | | | | |
Collapse
|
40
|
Bridier A, Meylheuc T, Briandet R. Realistic representation of Bacillus subtilis biofilms architecture using combined microscopy (CLSM, ESEM and FESEM). Micron 2013; 48:65-9. [PMID: 23517761 DOI: 10.1016/j.micron.2013.02.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 02/25/2013] [Accepted: 02/25/2013] [Indexed: 11/20/2022]
Abstract
In this contribution, we used a set of microscopic techniques including confocal laser scanning microscopy (CLSM), environmental scanning electron microscopy (ESEM) and field emission scanning electron microscopy (FESEM) to analyze the three-dimensional spatial arrangement of cells and their surrounding matrix in Bacillus subtilis biofilm. The combination of the different techniques enabled a deeper and realistic deciphering of biofilm architecture by providing the opportunity to overcome the limits of each single technique.
Collapse
Affiliation(s)
- A Bridier
- INRA, UMR 1319 Micalis, F-78350 Jouy-en-Josas, France
| | | | | |
Collapse
|
41
|
Loera-Muro VM, Jacques M, Tremblay YDN, Avelar-González FJ, Loera Muro A, Ramírez-López EM, Medina-Figueroa A, González-Reynaga HM, Guerrero-Barrera AL. Detection of Actinobacillus pleuropneumoniae in drinking water from pig farms. MICROBIOLOGY-SGM 2013; 159:536-544. [PMID: 23347956 DOI: 10.1099/mic.0.057992-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Actinobacillus pleuropneumoniae is the aetiological agent of porcine pleuropneumonia and is normally transmitted by aerosols and direct contact between animals. A. pleuropneumoniae has traditionally been considered an obligate pathogen of pigs and its presence in the environment has yet to be investigated. Here, the presence of A. pleuropneumoniae was detected in drinking water of pig farms in Mexico using a PCR specific for the RTX toxin gene, apxIV. The presence of A. pleuropneumoniae in farm drinking water was confirmed by indirect immunofluorescence using an A. pleuropneumoniae-specific polyclonal antibody and by fluorescent in situ hybridization. Viable bacteria from the farm drinking water were detected using the Live/Dead BacLight stain. Additionally, viable A. pleuropneumoniae was selected and isolated using the cAMP test and the identity of the isolated bacteria were confirmed by Gram staining, a specific polyclonal antibody and an A. pleuropneumoniae-specific PCR. Furthermore, biofilms were observed by scanning electron microscopy in A. pleuropneumoniae-positive samples. In conclusion, our data suggest that viable A. pleuropneumoniae is present in the drinking water of swine farms and may use biofilm as a strategy to survive in the environment.
Collapse
Affiliation(s)
- Victor M Loera-Muro
- Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags., C. P. 20131, Mexico
| | - Mario Jacques
- Groupe de recherche sur la maladies infectieuses du porc, Faculté de médecine vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 7C6, Canada
| | - Yannick D N Tremblay
- Groupe de recherche sur la maladies infectieuses du porc, Faculté de médecine vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 7C6, Canada
| | - Francisco J Avelar-González
- Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags., C. P. 20131, Mexico
| | - Abraham Loera Muro
- Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags., C. P. 20131, Mexico
| | - Elsa M Ramírez-López
- Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags., C. P. 20131, Mexico
| | - Alejandra Medina-Figueroa
- Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags., C. P. 20131, Mexico
| | - Higinio M González-Reynaga
- Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags., C. P. 20131, Mexico
| | - Alma L Guerrero-Barrera
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags., C. P. 20131, Mexico
| |
Collapse
|
42
|
Domenech M, García E, Prieto A, Moscoso M. Insight into the composition of the intercellular matrix of Streptococcus pneumoniae biofilms. Environ Microbiol 2012; 15:502-16. [PMID: 22913814 DOI: 10.1111/j.1462-2920.2012.02853.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 07/21/2012] [Indexed: 12/01/2022]
Abstract
Biofilm matrices consist of a mixture of extracellular polymeric substances synthesized in large part by the biofilm-producing microorganisms themselves. These matrices are responsible for the cohesion and three-dimensional architecture of biofilms. The present study demonstrates the existence of a matrix composed of extracellular DNA, proteins and polysaccharides in the biofilm formed by the human pathogen Streptococcus pneumoniae. Extracellular DNA, visualized by fluorescent labelling, was an important component of this matrix. The existence of DNA-protein complexes associated with bacterial aggregates and other polymers was hypothesized based on the unexpected DNA binding activity of lysozyme LytC, a novel moonlighting protein. Actually, a 25-amino-acid-long peptide derived from LytC (positions 408 and 432 of the mature LytC) was also capable of efficiently binding to DNA. Moreover, the presence of intercellular DNA-LytC protein complexes in pneumococcal biofilms was demonstrated by confocal laser scanning microscopy. Evidence of extracellular polysaccharide different from the capsule was obtained by staining with Calcofluor dye and four types of lectin conjugated to Alexa fluorophores, and by incubation with glycoside hydrolases. The presence of residues of Glcp(1→4) and GlcNAc(1→4) (in its deacetylated form) in the pneumococcal biofilm was confirmed by GC-MS techniques.
Collapse
Affiliation(s)
- Mirian Domenech
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | | | | | | |
Collapse
|
43
|
Baird FJ, Wadsworth MP, Hill JE. Evaluation and optimization of multiple fluorophore analysis of a Pseudomonas aeruginosa biofilm. J Microbiol Methods 2012; 90:192-6. [PMID: 22587931 DOI: 10.1016/j.mimet.2012.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 05/01/2012] [Accepted: 05/01/2012] [Indexed: 11/29/2022]
Abstract
Conventional laser scanning microscopy for multiple fluorescent stains can be a useful tool if the problems of autofluorescence and cross-talk are eliminated. The technique of spectral imaging was employed to unmix five different fluorophores - ranging in emission from 435 to 665 nm - applied to a Pseudomonas aeruginosa biofilm with overlapping spectra and which was not possible using traditional channel mode operation. Using lambda scanning and linear unmixing, the five fluorophores could be distinguished with regions of differentiation apparent.
Collapse
Affiliation(s)
- Fiona J Baird
- University of Vermont, School of Engineering, Burlington, Vermont 05405-0156, USA
| | | | | |
Collapse
|
44
|
Karcz J, Bernas T, Nowak A, Talik E, Woznica A. Application of lyophilization to prepare the nitrifying bacterial biofilm for imaging with scanning electron microscopy. SCANNING 2012; 34:26-36. [PMID: 21866557 DOI: 10.1002/sca.20275] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 07/11/2011] [Indexed: 05/31/2023]
Abstract
Structure of bacterial biofilms may be investigated using several variants of scanning electron microscopy (SEM). We apply lyophilization to prepare nitrifying bacterial biofilm for conventional SEM imaging in high-vacuum mode (CSEM). We therefore replace standard biofilm fixation in glutaraldehyde cross-linking, ethanol dehydration, and critical-point drying (CPD) with less-invasive low-temperature drying by sublimation in vacuum. We compare this approach with: (1) standard preparation with glutaraldehyde fixation, ethanol dehydration, and CPD before CSEM, (2) cryo-sputter preparation of rapidly frozen biofilm in hydrated state (cryo-SEM), and (3) in situ observation without any sample pretreatment in environmental SEM. Combined imaging with these modalities revealed two distinct immobilization patterns on the polyurethane foam: (1) large irregular aggregates (flocs) of bacterial biofilm that exist as irregular biofilm fragments, rope-like structures, or biofilm layers on the foam surface; (2) biofilm threads adherent to the surface of polyurethane foam. Our results indicate that lyophilization was suitable for preservation of bacterial cells and many forms of structure of extracellular matrix. The lyophilized material could be imaged with high resolution (using CSEM) to generate structural information complementary to that obtained with other SEM techniques.
Collapse
Affiliation(s)
- Jagna Karcz
- Laboratory of Scanning Electron Microscopy, Faculty of Biology and Environmental Protection, University of Silesia, Katowice, Poland.
| | | | | | | | | |
Collapse
|
45
|
Gunawardana M, Moss JA, Smith TJ, Kennedy S, Kopin E, Nguyen C, Malone AM, Rabe L, Schaudinn C, Webster P, Srinivasan P, Sweeney ED, Smith JM, Baum MM. Microbial biofilms on the surface of intravaginal rings worn in non-human primates. J Med Microbiol 2011; 60:828-837. [PMID: 21393449 DOI: 10.1099/jmm.0.028225-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Millions of intravaginal rings (IVRs) are used by women worldwide for contraception and for the treatment of vaginal atrophy. These devices also are suitable for local and systemic sustained release drug delivery, notably for antiviral agents in human immunodeficiency virus pre-exposure prophylaxis. Despite the widespread use of IVRs, no studies have examined whether surface-attached bacterial biofilms develop in vivo, an important consideration when determining the safety of these devices. The present study used scanning electron microscopy, fluorescence in situ hybridization and confocal laser scanning microscopy to study biofilms that formed on the surface of IVRs worn for 28 days by six female pig-tailed macaques, an excellent model organism for the human vaginal microbiome. Four of the IVRs released the nucleotide analogue reverse transcriptase inhibitor tenofovir at a controlled rate and the remaining two were unmedicated. Large areas of the ring surfaces were covered with monolayers of epithelial cells. Two bacterial biofilm phenotypes were found to develop on these monolayers and both had a broad diversity of bacterial cells closely associated with the extracellular material. Phenotype I, the more common of the two, consisted of tightly packed bacterial mats approximately 5 µm in thickness. Phenotype II was much thicker, typically 40 µm, and had an open architecture containing interwoven networks of uniform fibres. There was no significant difference in biofilm thickness and appearance between medicated and unmedicated IVRs. These preliminary results suggest that bacterial biofilms could be common on intravaginal devices worn for extended periods of time.
Collapse
Affiliation(s)
- Manjula Gunawardana
- Auritec Pharmaceuticals Inc., Suite 3, 1434 6th Street, Santa Monica, CA, USA.,Department of Chemistry, Oak Crest Institute of Science, 2275 E. Foothill Boulevard, Pasadena, CA, USA
| | - John A Moss
- Department of Chemistry, Oak Crest Institute of Science, 2275 E. Foothill Boulevard, Pasadena, CA, USA
| | - Thomas J Smith
- Department of Ophthalmology, University of Kentucky, Lexington, KY, USA.,Auritec Pharmaceuticals Inc., Suite 3, 1434 6th Street, Santa Monica, CA, USA.,Department of Chemistry, Oak Crest Institute of Science, 2275 E. Foothill Boulevard, Pasadena, CA, USA
| | - Sean Kennedy
- Department of Chemistry, Oak Crest Institute of Science, 2275 E. Foothill Boulevard, Pasadena, CA, USA
| | - Etana Kopin
- Auritec Pharmaceuticals Inc., Suite 3, 1434 6th Street, Santa Monica, CA, USA
| | - Cali Nguyen
- Auritec Pharmaceuticals Inc., Suite 3, 1434 6th Street, Santa Monica, CA, USA.,Department of Chemistry, Oak Crest Institute of Science, 2275 E. Foothill Boulevard, Pasadena, CA, USA
| | - Amanda M Malone
- Auritec Pharmaceuticals Inc., Suite 3, 1434 6th Street, Santa Monica, CA, USA
| | - Lorna Rabe
- Magee-Womens Research Institute, Pittsburgh, PA, USA
| | - Christoph Schaudinn
- Ahmanson Advanced EM & Imaging Center, House Ear Institute, 2100 W. 3rd Street, Los Angeles, CA, USA
| | - Paul Webster
- Ahmanson Advanced EM & Imaging Center, House Ear Institute, 2100 W. 3rd Street, Los Angeles, CA, USA
| | - Priya Srinivasan
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, STD, TB Prevention, Coordinating Center for Infectious Diseases (CCID), Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Elizabeth D Sweeney
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, STD, TB Prevention, Coordinating Center for Infectious Diseases (CCID), Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - James M Smith
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, STD, TB Prevention, Coordinating Center for Infectious Diseases (CCID), Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Marc M Baum
- Department of Chemistry, Oak Crest Institute of Science, 2275 E. Foothill Boulevard, Pasadena, CA, USA
| |
Collapse
|
46
|
Morrow JB, Arango CP, Holbrook RD. Association of quantum dot nanoparticles with Pseudomonas aeruginosa biofilm. JOURNAL OF ENVIRONMENTAL QUALITY 2010; 39:1934-1941. [PMID: 21284290 DOI: 10.2134/jeq2009.0455] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Quantum dots (QDs) of two different surface chemistries (carboxyl [COOH] and polyethylene glycol [PEG] modified) were utilized to determine the impact of surface functionality on QD mobility and distribution in Pseudomonas aeruginosa PAO1 biofilms. Confocal laser scanning microscopy was utilized to evaluate QD association with biofilm components (proteins, cells, and polysaccharides). Quantum dots did not preferentially associate with cell surfaces compared but did colocalize with extracellular proteins in the biofilm matrix. Neither PEG nor COOH QDs were found to be internalized by individual bacterial cells. Neither QD functionality nor flow rate of QD application (0.3 mL min(-1) or 3.0 mL min(-1)) resulted in a marked difference in QD association with P. aeruginosa biofilms. However, center of density determinations indicated COOH QDs could more easily penetrate the biofilm matrix by diffusion than PEG QDs. Biofilms with PEG QDs associated had rougher polysaccharide layers and rougher cell distribution than biofilms with COOH QDs. This work suggests natural biofilms may serve as deposition locations in natural and engineered environmental systems, and biofilm structural parameters may change based on exposure to nanomaterials of varied physical characteristics.
Collapse
Affiliation(s)
- Jayne B Morrow
- Biochemical Science Division, National Institute of Standards and Technology, 100 Bureau Dr., MS 8312, Gaithersburg, MD 20878, USA.
| | | | | |
Collapse
|
47
|
Pécastaings S, Bergé M, Dubourg KM, Roques C. Sessile Legionella pneumophila is able to grow on surfaces and generate structured monospecies biofilms. BIOFOULING 2010; 26:809-819. [PMID: 20835931 DOI: 10.1080/08927014.2010.520159] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Currently, models for studying Legionella pneumophila biofilm formation rely on multi-species biofilms with low reproducibility or on growth in rich medium, where planktonic growth is unavoidable. The present study describes a new medium adapted to the growth of L. pneumophila monospecies biofilms in vitro. A microplate model was used to test several media. After incubation for 6 days in a specific biofilm broth not supporting planktonic growth, biofilms consisted of 5.36 ± 0.40 log (cfu cm(-2)) or 5.34 ± 0.33 log (gu cm(-2)). The adhered population remained stable for up to 3 weeks after initial inoculation. In situ confocal microscope observations revealed a typical biofilm structure, comprising cell clusters ranging up to approximately 300 μm in height. This model is adapted to growing monospecies L. pneumophila biofilms that are structurally different from biofilms formed in a rich medium. High reproducibility and the absence of other microbial species make this model useful for studying genes involved in biofilm formation.
Collapse
Affiliation(s)
- S Pécastaings
- LU 49, Adhesion bacterienne et formation de biofilms, UPS, Universite de Toulouse, Toulouse, France.
| | | | | | | |
Collapse
|