scholarly journals Assessment of a weak mode of bacterial adhesion by applying an electric field

2020 ◽  
Author(s):  
George Araujo ◽  
Joy Zheng ◽  
Jae Jong Oh ◽  
Jay X. Tang
Keyword(s):  
Electric Field ◽  
Environmental Control ◽  
Caulobacter Crescentus ◽  
Surface Interaction ◽  
Bacterial Attachment ◽  
Stick Slip ◽  
Attached Bacteria ◽  
Plastic Surface ◽  
Unique Approach ◽  
Microbial Attachment

ABSTRACTMicrobial attachment to surfaces is ubiquitous in nature. Most species of bacteria attach and adhere to surfaces via special appendages such as pili and fimbriae, the roles of which have been extensively studied. Here we report an experiment on pilus-less mutants of Caulobacter crescentus weakly attached to a plastic surface and subjected to an electric field parallel to the surface. We find that some individual cells transiently but repeatedly adhere to the surface in a stick-slip fashion in the presence of an electric field. Even while transiently detached, these bacteria move significantly slower than the unattached ones in the same field of view undergoing electrophoretic motion. We refer this behavior of repeated and transient attachment as “quasi-attachment”. The speed of the quasi-attached bacteria exhibits large variations, frequently dropping close to zero for short intervals of time. This study suggests applying electric field as a useful method to investigate bacteria-surface interaction, which is significant in broader contexts such as infection and environmental control.SignificanceInteraction between bacteria and surfaces occur widely in nature, including those in industrial, environmental, and medical settings. It is therefore important to understand various mechanisms and factors that affect numerous forms of bacterium-surface interaction, particularly those resulting in adhesion or attachment, be they strong or weak, permanent or transient. This work takes a unique approach to identify a transient and reversible mode of bacterial attachment to a solid surface, by applying an electric field to exert a force for detachment. The force thus exerted proves to reach the amplitude required to detach bacteria of a pilus-less strain that weakly attach to a plastic surface. The method may be applied broadly to investigate bacteria-surface interaction.

scholarly journals Assessment of a Weak Mode of Bacterial Adhesion by Applying an Electric Field

2021 ◽  
Vol 1 (2) ◽  
pp. 255-269
Author(s):  
George Araujo ◽  
Zhaoyi Zheng ◽  
Jae Jong Oh ◽  
Jay X. Tang
Keyword(s):  
Electric Field ◽  
Bacterial Adhesion ◽  
Environmental Control ◽  
Caulobacter Crescentus ◽  
Field Of View ◽  
Stick Slip ◽  
Short Intervals ◽  
Attached Bacteria ◽  
Experimental Findings ◽  
Microbial Attachment

Microbial attachment to surfaces is ubiquitous in nature. Most species of bacteria attach and adhere to surfaces via special appendages such as pili and fimbriae, the roles of which have been extensively studied. Here, we report an experiment on pilus-less mutants of Caulobacter crescentus weakly attached to polyethylene surface. We find that some individual cells transiently but repeatedly adhere to the surface in a stick-slip fashion in the presence of an electric field parallel to the surface. These bacteria move significantly slower than the unattached ones in the same field of view undergoing electrophoretic motion. We refer this behavior of repeated and transient attachment as “quasi-attachment”. The speed of the quasi-attached bacteria exhibits large variation, frequently dropping close to zero for short intervals of time. We propose a polymeric tethering model to account for the experimental findings. This study sheds light on bacteria–surface interaction, which is significant in broader contexts such as infection and environmental control.

Bacterial Attachment To Uro-Epithelial Cells: Mechanisms and Consequences

1997 ◽  
Vol 11 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Hugh Connell ◽  
Maria Hedlund ◽  
William Agace ◽  
Catharina Svanborg
Keyword(s):  
Epithelial Cells ◽  
Bacterial Attachment ◽  
Mucosal Barrier ◽  
Mucosal Inflammation ◽  
Local Site ◽  
Mucosal Surfaces ◽  
Mucosal Infection ◽  
Gain Access ◽  
Host Tissues ◽  
Microbial Attachment

Microbial attachment to mucosal surfaces is a first step in mucosal infection. Specific interactions between microbial surface ligands and host receptors influence the distribution of microbes in their sites of infection. Adhesion has often been regarded as a sufficient end point, explaining tissue tropism and bacterial persistence at mucosal sites. Adherence, however, is also a virulence factor through which microbes gain access to host tissues, upset the integrity of the mucosal barrier, and cause disease. The induction of mucosal inflammation is one aspect of this process. Bacterial attachment to mucosal surfaces activates the production of pro-inflammatory cytokines that cause both local and systemic inflammation. Epithelial cells are one source of these cytokines. The binding of fimbrial lectins to epithelial cell receptors triggers transmembrane signaling events that upregulate cytokine-specific mRNA and increase cytokine secretion. P fimbriae that bind the globoseries of glycolipids cause the release of ceramides and activation of the ceramide signaling pathway which contributes to the IL-6 response. Spread of cytokines and other pro-inflammatory mediators from the local site contributes to the symptoms and signs of infection.

scholarly journals Fluorescence-Based Bacterial Overlay Method for Simultaneous In Situ Quantification of Surface-Attached Bacteria

2007 ◽  
Vol 73 (8) ◽  
pp. 2653-2660 ◽  
Author(s):  
Rainer Müller ◽  
Gerhard Gröger ◽  
Karl-Anton Hiller ◽  
Gottfried Schmalz ◽  
Stefan Ruhl
Keyword(s):  
Surface Chemistry ◽  
Bacterial Adhesion ◽  
Bacterial Attachment ◽  
Bacterial Adherence ◽  
Model Organisms ◽  
Adhesion Properties ◽  
Attached Bacteria ◽  
Overlay Method ◽  
Biomaterial Surfaces

ABSTRACT For quantification of bacterial adherence to biomaterial surfaces or to other surfaces prone to biofouling, there is a need for methods that allow a comparative analysis of small material specimens. A new method for quantification of surface-attached biotinylated bacteria was established by in situ detection with fluorescence-labeled avidin-D. This method was evaluated utilizing a silicon wafer model system to monitor the influences of surface wettability and roughness on bacterial adhesion. Furthermore, the effects of protein preadsorption from serum, saliva, human serum albumin, and fibronectin were investigated. Streptococcus gordonii, Streptococcus mitis, and Staphylococcus aureus were chosen as model organisms because of their differing adhesion properties and their clinical relevance. To verify the results obtained by this new technique, scanning electron microscopy and agar replica plating were employed. Oxidized and poly(ethylene glycol)-modified silicon wafers were found to be more resistant to bacterial adhesion than wafers coated with hydrocarbon and fluorocarbon moieties. Roughening of the chemically modified surfaces resulted in an overall increase in bacterial attachment. Preadsorption of proteins affected bacterial adherence but did not fully abolish the influence of the original surface chemistry. However, in certain instances, mostly with saliva or serum, masking of the underlying surface chemistry became evident. The new bacterial overlay method allowed a reliable quantification of surface-attached bacteria and could hence be employed for measuring bacterial adherence on material specimens in a variety of applications.

Numerical Analysis of the Effect of Non Uniform Electric Field on the Trajectory of Micro Water Jet

2015 ◽  
Author(s):  
Satyabrata Mohanty ◽  
Kornel F. Ehmann ◽  
Jian Cao
Keyword(s):  
Numerical Analysis ◽  
Electric Field ◽  
Jet Impingement ◽  
Water Jet ◽  
Uniform Electric Field ◽  
Static Electric Field ◽  
Liquid Dielectrophoresis ◽  
Fine Control ◽  
Unique Approach ◽  
And Control

In spite of its inherent advantages as a manufacturing tool, water-jet has not been extensively applied to the field of micro-manufacturing due to its low tolerance and poor control of the position of jet impingement. This paper explores the possibility of using the phenomenon of liquid dielectrophoresis to deflect and control the trajectory of a water jet in air. An approach is suggested using a localized non-uniform static electric field over a micro water jet with diameters in the range of 25–100 micrometers. The water jet has been modelled as a thin dielectric column and the numerical analysis of the electric field distribution has been carried out using COMSOL to analyze the generated forces and predict the scale of deflection of the jet. This unique approach of harnessing the polar nature of water using the phenomenon of dielectrophoresis might be useful in achieving fine control of the water jet’s trajectory especially in micro water jet material processing.

scholarly journals On the optical measurement of microparticle charge using quantum dots

2021 ◽  
Author(s):  
Mikhail Pustylnik ◽  
Zahra Marvi ◽  
J Beckers
Keyword(s):  
Quantum Dots ◽  
Electric Field ◽  
Visible Light ◽  
Photoluminescence Spectrum ◽  
Optical Measurement ◽  
Stark Shift ◽  
Surface Interaction ◽  
Local Electric Field ◽  
Plasma Surface ◽  
Stationary Configuration

Abstract We investigated the possibility of using a layer of quantum dots (QDs) deposited on the microparticle surface for the measurement of the charge the microparticle acquires when immersed into a plasma. To that end, we performed the calculations of the Stark shift of the photoluminescence spectrum of QDs caused by the fluctuating local electric field. In our calculations, we assumed the plasma-delivered surplus electrons to be distributed on the surface of a microparticle. According to our calculations, the Stark shift will acquire measurable values when the lifetime of the quasi-stationary configuration of the surplus electrons will be determined by their diffusion along the surface. Experiments with flat QD-covered floating plasma-facing surfaces suggest that measurable Stark shift of the photoluminescence spectrum can be achieved. Based on our model, modern microscopic plasma-surface interaction theories and analysis of the experiments, we suggest the possible design of the charge microsensor, which will allow to measure the charge accumulated on its surface by means of visible-light optics.

Sanitizer Efficacy Against Attached Bacteria in a Milk Biofilm

1993 ◽  
Vol 56 (1) ◽  
pp. 34-41 ◽  
Author(s):  
T. M. MOSTELLER ◽  
J. R. BISHOP
Keyword(s):  
Fatty Acid ◽  
Pseudomonas Fluorescens ◽  
Yersinia Enterocolitica ◽  
Bacterial Attachment ◽  
Processing Conditions ◽  
Attached Bacteria ◽  
Rubber Surface ◽  
Test Organisms ◽  
Plate Counts ◽  
Direct Epifluorescent Filter Technique

Pseudomonas fluorescens, Yersinia enterocolitica, and Listeria monocytogenes were shown to readily attach to both rubber and Teflon® surfaces. Sanitizer efficacy testing done in the laboratory with nonadherent bacteria could lead to false assumptions as to the sanitizer's true effectiveness under processing conditions where cells may be attached. The objectives in this study were: (a) evaluate the efficacy of in-use concentrations of sanitizers on bacteria attached to gasket materials, (b) compare bacterial attachment to rubber and Teflon® gaskets, (c) examine different methods of enumeration, and (d) compare sanitizer efficacy on attached and suspended bacteria. The goal reduction for all of the sanitizers tested was ≥3 log cycles or 99.9%. Results indicated that iodophor, hypochlorite, acid anionic, peroxyacetic acid, fatty acid, and quaternary ammonium sanitizers failed to provide an adequate reduction in the numbers of attached bacteria at levels of 104 to 105/mm2 in most cases. The test organisms attached in slightly higher numbers to the rubber surface versus Teflon®. Plate counts, impedance microbiology, and the direct epifluorescent filter technique were tested as methods of enumeration. Impedance microbiology was the best method of enumeration, since it allowed the estimation of both reversibly and irreversibly attached bacteria. The efficacy of sanitizers versus a bacterial suspensions resulted in a ≥ 5 log-cycle reduction. The same concentrations were relatively ineffective against the attached bacteria. The goal reduction was reached on the Teflon® surface with the iodophor, hypochlorite, and fatty acid sanitizers with a log-cycle reduction in the number of Yersinia enterocolitica of 3.09, 3.19, and 3.31, respectively. Pseudomonas fluorescens was reduced by 3.16 on both the rubber and Teflon® surfaces when exposed to the hypochlorite sanitizer.

scholarly journals Effects of Pre-Treatment Using Plasma on the Antibacterial Activity of Mushroom Surfaces

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1888
Author(s):  
Sarmistha Mitra ◽  
Mayura Veerana ◽  
Eun-Ha Choi ◽  
Gyungsoon Park
Keyword(s):  
Lipid Peroxidation ◽  
Atmospheric Pressure ◽  
Treatment Time ◽  
Reduction Rate ◽  
Atmospheric Pressure Plasma ◽  
Bacterial Attachment ◽  
Pressure Plasma ◽  
Attached Bacteria ◽  
Pre Treatment

Although non-thermal atmospheric pressure plasma is an efficient tool for preventing post-harvest microbial contamination, many studies have focused on the post-treatment of infected or contaminated foods. In this study, we examined the antimicrobial quality of mushrooms pre-treated with a non-thermal atmospheric pressure plasma jet (NTAPPJ) or plasma-treated water (PTW). The CFU (Colony Forming Unit) number of Escherichia coli inoculated on surfaces of mushrooms pre-treated with NTAPPJ or PTW was significantly reduced (about 60–75% for NTAPPJ and about 35–85% for PTW), and the reduction rate was proportional to the treatment time. Bacterial attachment and viability of the attached bacteria were decreased on NTAPPJ-treated mushroom surfaces. This may be caused by the increased hydrophilicity and oxidizing capacity observed on NTAPPJ-treated mushroom surfaces. In PTW-treated mushrooms, bacterial attachment was not significantly changed, but death and lipid peroxidation of the attached bacteria were significantly increased. Analysis of mushroom quality showed that loss of water content was greater in mushrooms treated with NTAPPJ compared to that in those with no treatment (control) and PTW treatment during storage. Our results suggest that pre-treatment with NTAPPJ or PTW can improve the antibacterial quality of mushroom surfaces by decreasing bacterial attachment (for NTAPPJ) and increasing bacterial lipid peroxidation (for both NTAPPJ and PTW).

Sign in / Sign up

Export Citation Format

Share Document