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Computer Added Simulation of the Spread of Multidrug-Resistant Bacteria in an Radiation Therapy Shelter Based on Computational Fluid Dynamics. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:4760823. [PMID: 35844457 PMCID: PMC9279081 DOI: 10.1155/2022/4760823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/29/2022] [Accepted: 06/03/2022] [Indexed: 11/17/2022]
Abstract
Purpose Due to the poor ventilation and air stagnation in the radiation therapy ward, it is easy to cause respiratory disease transmission, which brings about the public health safety problem of infection. In order to alleviate this problem, we propose a research method based on computational fluid dynamics (CFD). Method A three-dimensional model of a radiation therapy ward is established, and the CFD software framework is used to numerically simulate the air flow field in the constrained radiation therapy ward environment. We computed the influence of the spray speed, particle size, and inlet content of respiratory droplets on the flow and spread of multidrug-resistant bacteria. Results In the range of the horizontal transmission line X from 0 to 3 meters, when the transmission speed (V) is 35 m/s, the multidrug-resistant bacteria concentration reaches the highest value. In the range of the vertical transmission line Y from 0 to 3 meters, when V is 35 m/s, the multidrug-resistant bacteria concentration reaches the highest value. Conclusion A large amount of data shows that there is a positive correlation between the respiratory droplet spray velocity, inlet content, and the multidrug-resistant bacteria flow propagation speed and concentration distribution. The respiratory droplet size mainly affects the peak concentration of the multidrug-resistant bacteria flow propagation.
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Zhou J, Dong S, Ma C, Wu Y, Qiu X. Epidemic spread simulation in an area with a high-density crowd using a SEIR-based model. PLoS One 2021; 16:e0253220. [PMID: 34138911 PMCID: PMC8211270 DOI: 10.1371/journal.pone.0253220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/31/2021] [Indexed: 11/19/2022] Open
Abstract
Understanding the spread of infectious diseases is an extremely essential step to preventing them. Thus, correct modeling and simulation approaches are critical for elucidating the transmission of infectious diseases and improving the control of epidemics. The primary objective of this study is to simulate the spread of communicable diseases in an urban rail transit station. Data were collected by a field investigation in the city of Ningbo, China. A SEIR-based model was developed to simulate the spread of infectious diseases in Tianyi station, considering four groups of passengers (susceptible, exposed, infected, and recovered) and a 14-day incubation period. Based on the historical data of infectious diseases, the parameters of the SEIR infectious disease model were clarified, and a sensitivity analysis of the parameters was also performed. The results showed that the contact rate (CR), infectivity (I), and average illness duration (AID) were positively correlated with the number of infections. It was also found that the length of the average incubation time (AIT) was positively correlated with the number of exposed individuals and negatively correlated with the number of infectors. These simulation results provide support for the validity and reliability of using the SEIR model in studies of the spread of epidemics and facilitate the development of effective measures to prevent and control an epidemic.
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Affiliation(s)
- Jibiao Zhou
- School of Civil and Transportation Engineering, Ningbo University of Technology, Ningbo, China
- Department of Traffic Engineering & Key Laboratory of Road and Traffic Engineering, Ministry of Education, Tongji University, Shanghai, China
| | - Sheng Dong
- School of Civil and Transportation Engineering, Ningbo University of Technology, Ningbo, China
| | - Changxi Ma
- School of Traffic and Transportation, Lanzhou Jiaotong University, Anning District, Lanzhou, China
| | - Yao Wu
- School of Modern Posts & Institute of Modern Posts, Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Xiao Qiu
- School of Civil Engineering and Transportation, Hohai University, Nanjing, China
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Neves SF, Ponmozhi J, Mergulhão FJ, Campos JBLM, Miranda JM. Cell adhesion in microchannel multiple constrictions - Evidence of mass transport limitations. Colloids Surf B Biointerfaces 2020; 198:111490. [PMID: 33262016 DOI: 10.1016/j.colsurfb.2020.111490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/30/2020] [Accepted: 11/20/2020] [Indexed: 01/22/2023]
Abstract
Biofilm growth (fouling) in microdevices is a critical concern in several industrial, engineering and health applications, particularly in novel high-performance microdevices often designed with complex geometries, narrow regions and multiple headers. Unfortunately, on these devices, the regions with local high wall shear stresses (WSS) also show high local fouling rates. Several explanations have been put forward by the scientific community, including the effect of cell transport by Brownian motion on the adhesion rate. In this work, for the first time, both WSS and convection and Brownian diffusion effects on cell adhesion were evaluated along a microchannel with intercalate constriction and expansion zones designed to mimic the hydrodynamics of the human body and biomedical devices. Convection and Brownian diffusion effects were numerically studied using a steady-state convective-diffusion model (convection, diffusion and sedimentation). According to the numerical results, the convection and Brownian diffusion effects on cell adhesion are effectively more significant in regions with high WSS. Furthermore, a good agreement was observed between experimental and predicted local Sherwood numbers, particularly at the entrance and within the multiple constrictions. However, further mechanisms should be considered to accurately predict cell adhesion in the expansion zones. The described numerical approach can be used as a way to identify possible clogging zones in microchannels, and defining solutions, even before the construction of the prototype.
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Affiliation(s)
- S F Neves
- CEFT - Transport Phenomena Research Center, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - J Ponmozhi
- CEFT - Transport Phenomena Research Center, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal; IES- Institute of Engineering & Science IPS Academy Knowledge Village, Rajendra Nagar A.B. Road, Indore, 452012, India
| | - F J Mergulhão
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - J B L M Campos
- CEFT - Transport Phenomena Research Center, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - J M Miranda
- CEFT - Transport Phenomena Research Center, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal.
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Analysing the Initial Bacterial Adhesion to Evaluate the Performance of Antifouling Surfaces. Antibiotics (Basel) 2020; 9:antibiotics9070421. [PMID: 32709041 PMCID: PMC7400106 DOI: 10.3390/antibiotics9070421] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/11/2020] [Accepted: 07/15/2020] [Indexed: 12/16/2022] Open
Abstract
The aim of this work was to study the initial events of Escherichia coli adhesion to polydimethylsiloxane, which is critical for the development of antifouling surfaces. A parallel plate flow cell was used to perform the initial adhesion experiments under controlled hydrodynamic conditions (shear rates ranging between 8 and 100/s), mimicking biomedical scenarios. Initial adhesion studies capture more accurately the cell-surface interactions as in later stages, incoming cells may interact with the surface but also with already adhered cells. Adhesion rates were calculated and results shown that after some time (between 5 and 9 min), these rates decreased (by 55% on average), from the initial values for all tested conditions. The common explanation for this decrease is the occurrence of hydrodynamic blocking, where the area behind each adhered cell is screened from incoming cells. This was investigated using a pair correlation map from which two-dimensional histograms showing the density probability function were constructed. The results highlighted a lower density probability (below 4.0 × 10−4) of the presence of cells around a given cell under different shear rates irrespectively of the radial direction. A shadowing area behind the already adhered cells was not observed, indicating that hydrodynamic blocking was not occurring and therefore it could not be the cause for the decreases in cell adhesion rates. Afterward, cell transport rates from the bulk solution to the surface were estimated using the Smoluchowski-Levich approximation and values in the range of 80–170 cells/cm2.s were obtained. The drag forces that adhered cells have to withstand were also estimated and values in the range of 3–50 × 10−14 N were determined. Although mass transport increases with the flow rate, drag forces also increase and the relative importance of these factors may change in different conditions. This work demonstrates that adjustment of operational parameters in initial adhesion experiments may be required to avoid hydrodynamic blocking, in order to obtain reliable data about cell-surface interactions that can be used in the development of more efficient antifouling surfaces.
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Hulander M, Valen-Rukke H, Sundell G, Andersson M. Influence of Fibrinogen on Staphylococcus epidermidis Adhesion Can Be Reversed by Tuning Surface Nanotopography. ACS Biomater Sci Eng 2019; 5:4323-4330. [DOI: 10.1021/acsbiomaterials.9b00450] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mats Hulander
- Chalmers University of Technology, Chalmersplatsen 4, 412 96 Göteborg, Sweden
- Nordic Institute of Dental Materials, Sognsveien 70 A, 0855 Oslo, Norway
| | - Håkon Valen-Rukke
- Nordic Institute of Dental Materials, Sognsveien 70 A, 0855 Oslo, Norway
| | - Gustav Sundell
- Chalmers University of Technology, Chalmersplatsen 4, 412 96 Göteborg, Sweden
| | - Martin Andersson
- Chalmers University of Technology, Chalmersplatsen 4, 412 96 Göteborg, Sweden
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6
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Palabiyik I, Lopez‐Quiroga E, Robbins PT, Goode KR, Fryer PJ. Removal of yield‐stress fluids from pipework using water. AIChE J 2018. [DOI: 10.1002/aic.16105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Phillip T. Robbins
- School of Chemical EngineeringUniversity of BirminghamEdgbaston BirminghamB15 2TT U.K
| | - Kylee R. Goode
- School of Chemical EngineeringUniversity of BirminghamEdgbaston BirminghamB15 2TT U.K
| | - Peter J. Fryer
- School of Chemical EngineeringUniversity of BirminghamEdgbaston BirminghamB15 2TT U.K
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Castelain M, Duviau MP, Oxaran V, Schmitz P, Cocaign-Bousquet M, Loubière P, Piard JC, Mercier-Bonin M. Oligomerized backbone pilin helps piliated Lactococcus lactis to withstand shear flow. BIOFOULING 2016; 32:911-923. [PMID: 27472256 DOI: 10.1080/08927014.2016.1213817] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
The present work focuses on the role of pili present at the cell surface of Lactococcus lactis in bacterial adhesion to abiotic (hydrophobic polystyrene) and biotic (mucin-coated polystyrene) surfaces. Native pili-displaying strains and isogenic derivatives in which pilins or sortase C structural genes had been modified were used. Surface physico-chemistry, morphology and shear-flow-induced detachment of lactococcal cells were evaluated. The involvement of pili in L. lactis adhesion was clearly demonstrated, irrespective of the surface characteristics (hydrophobic/hydrophilic, presence or not of specific binding sites). The accessory pilin, PilC, and the backbone pilin, PilB, were revealed to play a major role in adhesion, provided that the PilB was present in its polymerized form. Within the population fraction that remained attached to the surface under increasing shear flow, different association behaviors were observed, showing that pili could serve as anchoring sites thus hampering the effect of shear flow on cell orientation and detachment.
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Affiliation(s)
- Mickaël Castelain
- a LISBP, Université de Toulouse, CNRS, INRA, INSA , Toulouse , France
| | | | - Virginie Oxaran
- b Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay , Jouy-en-Josas , France
| | - Philippe Schmitz
- a LISBP, Université de Toulouse, CNRS, INRA, INSA , Toulouse , France
| | | | - Pascal Loubière
- a LISBP, Université de Toulouse, CNRS, INRA, INSA , Toulouse , France
| | - Jean-Christophe Piard
- b Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay , Jouy-en-Josas , France
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A major secretory defect of tumour-infiltrating T lymphocytes due to galectin impairing LFA-1-mediated synapse completion. Nat Commun 2016; 7:12242. [PMID: 27447355 PMCID: PMC4961845 DOI: 10.1038/ncomms12242] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 06/15/2016] [Indexed: 12/20/2022] Open
Abstract
Surface galectin has been shown to contribute to dysfunctions of human tumour-infiltrating lymphocytes (TILs). We show here that galectin-covered CD8 TILs produce normal amounts of intracellular cytokines, but fail to secrete them because of defective actin rearrangements at the synapse. The non-secreting TILs also display reduced adhesion to their targets, together with defective LFA-1 recruitment and activation at the synapse. These defects are relieved by releasing surface galectin. As mild LFA-1 blockade on normal blood T cells emulate the defects of galectin-covered TILs, we conclude that galectin prevents the formation of a functional secretory synapse by preventing optimal LFA-1 triggering. Our results highlight a major secretory defect of TILs that is not revealed by widely used intracellular cytokine immunomonitoring assays. They also provide additional insights into the T-cell response, by showing that different thresholds of LFA-1 triggering are required to promote the intracellular production of cytokines and their secretion. Galectin-3 is a sugar-binding protein that can inhibit antitumour cytotoxic immunity. Here the authors show that Galectin-3 expressed by tumour cells inhibits LFA-1 on cytotoxic lymphocytes, impairing immunological synapse formation, IFNg secretion, and target cell killing.
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Dimartino S, Savory DM, Fraser-Miller SJ, Gordon KC, McQuillan AJ. Microscopic and infrared spectroscopic comparison of the underwater adhesives produced by germlings of the brown seaweed species Durvillaea antarctica and Hormosira banksii. J R Soc Interface 2016; 13:20151083. [PMID: 27122179 PMCID: PMC4874429 DOI: 10.1098/rsif.2015.1083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/31/2016] [Indexed: 11/12/2022] Open
Abstract
Adhesives from marine organisms are often the source of inspiration for the development of glues able to create durable bonds in wet environments. In this work, we investigated the adhesive secretions produced by germlings of two large seaweed species from the South Pacific, Durvillaea antarctica, also named 'the strongest kelp in the word', and its close relative Hormosira banksii The comparative analysis was based on optical and scanning electron microscopy imaging as well as Fourier transform infrared (FTIR) spectroscopy and principal component analysis (PCA). For both species, the egg surface presents peripheral vesicles which are released soon after fertilization to discharge a primary adhesive. This is characterized by peaks representative of carbohydrate molecules. A secondary protein-based adhesive is then secreted in the early developmental stages of the germlings. Energy dispersive X-ray, FTIR and PCA indicate that D. antarctica secretions also contain sulfated moieties, and become cross-linked with time, both conferring strong adhesive and cohesive properties. On the other hand, H. banksii secretions are complemented by the putative adhesive phlorotannins, and are characterized by a simple mechanism in which all constituents are released with the same rate and with no apparent cross-linking. It is also noted that the release of adhesive materials appears to be faster and more copious in D. antarctica than in H. banksii Overall, this study highlights that both quantity and quality of the adhesives matter in explaining the superior attachment ability of D. antarctica.
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Affiliation(s)
- Simone Dimartino
- Department of Chemical and Process Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - David M Savory
- Department of Chemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Sara J Fraser-Miller
- Department of Chemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand The Dodd-Walls Centre, University of Otago, Dunedin 9054, New Zealand
| | - Keith C Gordon
- Department of Chemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand The Dodd-Walls Centre, University of Otago, Dunedin 9054, New Zealand
| | - A James McQuillan
- Department of Chemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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Yoshihara A, Nobuhira N, Narahara H, Toyoda S, Tokumoto H, Konishi Y, Nomura T. Estimation of the adhesive force distribution for the flagellar adhesion of Escherichia coli on a glass surface. Colloids Surf B Biointerfaces 2015; 131:67-72. [PMID: 25956746 DOI: 10.1016/j.colsurfb.2015.04.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/09/2015] [Accepted: 04/15/2015] [Indexed: 01/20/2023]
Abstract
The effects of the presence or absence of microbial flagella and the microbial motility on the colloidal behaviors of microbial cells were quantitatively evaluated. The microbial cell attachment and detachment processes on a glass surface were observed directly using a parallel-plate flow chamber. Wild-type, flagellar paralyzed, and nonflagellated Escherichia coli strains were used as model microbial cells. In the cell attachment tests, the microbial adhesion rate in a 160mM NaCl solution was approximately 10 times higher than that in a 10mM solution, for all E. coli strains. The colloidal behavior of the microbial cells agreed well with the predictions of the DLVO theory. In addition, the microbial flagella and motility did not significantly affect the cell attachment, regardless of the existence of a potential barrier between the cell and the glass substratum. In the cell detachment tests, the cumulative number of microbial cells detached from the glass substratum with increasing flow rate was fit well with the Weibull distribution function. The list of strains arranged in order of increasing median drag force required to remove them was nonflagellated strain, flagellar paralyzed strain, and wild-type strain. These results indicated that the flagella and the flagellar motility inhibited the cell detachment from the glass substratum. Furthermore, a large external force would likely be required to inhibit the microbial adhesion in the early stage of the biofilm formation.
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Affiliation(s)
- Akinori Yoshihara
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan; Corporate Engineering Center, Corporate Production Management & Engineering Division, Sumitomo Bakelite Co., Ltd., 2100 Takayanagi, Fujieda, Shizuoka 426-0041, Japan.
| | - Noritaka Nobuhira
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hisaya Narahara
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Syunsuke Toyoda
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hayato Tokumoto
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Yasuhiro Konishi
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Toshiyuki Nomura
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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Dimartino S, Mather AV, Alestra T, Nawada S, Haber M. Experimental and computational analysis of a novel flow channel to assess the adhesion strength of sessile marine organisms. Interface Focus 2015; 5:20140059. [PMID: 25657838 DOI: 10.1098/rsfs.2014.0059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bioadhesives produced by marine macroalgae represent a potential source of inspiration for the development of water-resistant adhesives. Assessing their adhesion strength, however, remains difficult owing to low volumes of adhesive material produced, low solubility and rapid curing time. These difficulties can be circumvented by testing the adhesion strength of macroalgae propagules attached to a substrate. In this paper, we present a simple, novel flow channel used to test the adhesion strength of the germlings of the fucalean alga Hormosira banksii to four substrates of biomedical relevance (PMMA, agar, gelatin and gelatin + lipid). The adhesion strength of H. banksii germlings was found to increase in a time-dependent manner, with minimal adhesion success after a settlement period of 6 h and maximum adhesion strength achieved 24 h after initial settlement. Adhesion success increased most dramatically between 6 and 12 h settlement time, while no additional increase in adhesion strength was recorded for settlement times over 24 h. No significant difference in adhesion strength to the various substrates was observed. Computational fluid dynamics (CFD) was used to estimate the influence of fluid velocity and germling density on drag force acting on the settled organisms. CFD modelling showed that, on average, the drag force decreased with increasing germling number, suggesting that germlings would benefit from gregarious settlement behaviour. Collectively, our results contribute to a better understanding of the mechanisms allowing benthic marine organisms to thrive in hydrodynamically stressful environments and provide useful insights for further investigations.
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Affiliation(s)
- Simone Dimartino
- Department of Chemical and Process Engineering , University of Canterbury , Christchurch , New Zealand ; Biomolecular Interaction Centre , University of Canterbury , Christchurch , New Zealand
| | - Anton V Mather
- Department of Biological Sciences , University of Canterbury , Christchurch , New Zealand
| | - Tommaso Alestra
- Department of Biological Sciences , University of Canterbury , Christchurch , New Zealand
| | - Suhas Nawada
- Biomolecular Interaction Centre , University of Canterbury , Christchurch , New Zealand
| | - Meir Haber
- Biota Ltd , PO Box 220, Or Akiva 30600 , Israel
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Yoshihara A, Narahara H, Kuriyama Y, Toyoda S, Tokumoto H, Konishi Y, Nomura T. Measurement of microbial adhesive forces with a parallel plate flow chamber. J Colloid Interface Sci 2014; 432:77-85. [PMID: 25086382 DOI: 10.1016/j.jcis.2014.06.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 06/21/2014] [Accepted: 06/23/2014] [Indexed: 11/27/2022]
Abstract
HYPOTHESIS It was predicted that the colloidal behaviors of archaea and bacteria with disparate surface structure were different. In this study, the effects of the physicochemical properties of microbial cell surfaces on colloidal behavior were analyzed with Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, thermodynamics, and powder technology. EXPERIMENTS Cell attachment and detachment from model substrates were directly observed using a parallel plate flow chamber. Gram-negative Escherichia coli and archaeal Methanosarcina barkeri were used as model microbial cells, and positively and negatively charged glass slides were used as model substrates. FINDINGS Microbial adhesion on both substrates agreed well with predictions calculated from DLVO theory, using experimental parameters. The total number of cells detached from the substrates as a function of flow rate was fit with the Weibull distribution function. In addition, the drag force required for detachment, which was estimated from the hydrodynamic forces, had a wide distribution; however, the forces became smaller with increasing ionic strength because of reduced electrostatic interactions between the cells and the substrate. M. barkeri could not be detached from positively charged substrates because it would entail a negative change in the interfacial energy of interaction. Thus adhesion was thermodynamically favored in this case.
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Affiliation(s)
- Akinori Yoshihara
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan; Corporate Engineering Center, Corporate Production Management & Engineering Div., Sumitomo Bakelite Co., Ltd., 2100 Takayanagi, Fujieda, Shizuoka 426-0041, Japan
| | - Hisaya Narahara
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Yuta Kuriyama
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Syunsuke Toyoda
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hayato Tokumoto
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Yasuhiro Konishi
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Toshiyuki Nomura
- Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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13
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Mercier-Bonin M, Duviau MP, Ellero C, Lebleu N, Raynaud P, Despax B, Schmitz P. Dynamics of detachment of Escherichia coli from plasma-mediated coatings under shear flow. BIOFOULING 2012; 28:881-894. [PMID: 22963000 DOI: 10.1080/08927014.2012.719160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A series of plasma-mediated coatings, containing silver nanoparticles embedded in an organosilicon or silica-like matrix, were deposited onto stainless steel and chemically characterized. Their anti-adhesive properties were evaluated in vitro towards Escherichia coli by performing shear-flow induced detachment experiments. Increasing the wall shear stress facilitated E. coli cell detachment, irrespective of the coating characteristics. When nanosilver was incorporated, cell detachment was lower, probably due to the affinity of the embedded silver for biological components of the cell wall. The presence of methyl groups in the matrix network could also promote enhanced hydrophobic interactions. Within the population fraction remaining attached to the coating under increasing shear flow, different association phenotypes were observed, viz. progressively lying flat, moving laterally, remaining tethered, or rotating by a single anchoring point, until alignment with the flow direction. This re-orientation phenotype and its relation with detachment were dependent of the coating. The effects of such heterogeneities should be more deeply explored.
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Affiliation(s)
- Muriel Mercier-Bonin
- Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, Toulouse, F-31077, France.
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