Efficient suppression of biofilm formation by a nucleic acid aptamer

AbstractBiofilm formation is responsible for numerous chronic infections and represents a serious health challenge. Bacteria and the extracellular polysaccharides (EPS) cause biofilms to become adherent, toxic, resistant to antibiotics, and ultimately difficult to remove. Inhibition of EPS synthesis can prevent the formation of bacterial biofilms, reduce their robustness, and promote removal. Here, we have developed a framework nucleic acid delivery system with a tetrahedral configuration. It can easily access bacterial cells and functions by delivering antisense oligonucleotides that target specific genes. We designed antisense oligonucleotide sequences with multiple targets based on conserved regions of the VicK protein-binding site. Once delivered to bacterial cells, they significantly decreased EPS synthesis and biofilm thickness. Compared to existing approaches, this system is highly efficacious because it simultaneously reduces the expression of all targeted genes (gtfBCD, gbpB, ftf). We demonstrate a novel nucleic acid-based nanomaterial with multi-targeted inhibition that has great potential for the treatment of chronic infections caused by biofilms.

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Analysis of biofilm formation by Sporothrix schenckii

Medical Mycology ◽

10.1093/mmy/myaa027 ◽

2020 ◽

Vol 59 (1) ◽

pp. 31-40

Author(s):

Rocío Sánchez-Herrera ◽

Lérida Liss Flores-Villavicencio ◽

Juan Luis Pichardo-Molina ◽

José Pedro Castruita-Domínguez ◽

Xochilt Aparicio-Fernández ◽

...

Keyword(s):

Extracellular Matrix ◽

Life Cycle ◽

Nucleic Acid ◽

Biofilm Formation ◽

Structural Integrity ◽

Sporothrix Schenckii ◽

Extracellular Dna ◽

Pathogenic Microorganisms ◽

Subcutaneous Mycosis ◽

Biofilm Development

Abstract The development of mature biofilms is an aid in numerous aspects of the life cycle of fungi. It is well known that Sporothrix schenckii complex causes a benign subcutaneous mycosis, but recent studies have suggestedthat biofilm formation may be one of the important factors involved in its virulence. Here we report the study of the biomass organization and a model of the stages of S. schenckii biofilm development: adsorption, active adhesion, microcolony formation, maturation, and dispersal of biofilm fragments. During the development, the biofilm is surrounded by extracellular matrix, which contains glycoprotein (mannose rich), carbohydrates, lipids, and nucleic acid. In addition, the extracellular DNA increases in extracellular matrix as a key component to structural integrity and antifungal resistance. The study of S. schenckii biofilm contributes to a better understanding of growth biofilm and physiology, adding new insights into the mechanisms of virulence and persistence of pathogenic microorganisms.

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Csp1, A Cold-Shock Protein Homolog in Xylella fastidiosa Influences Pili Formation, Stress Response, and Gene Expression

10.1101/2021.07.21.453299 ◽

2021 ◽

Author(s):

Wei Wei ◽

Lindsey Price Burbank ◽

Teresa Sawyer

Keyword(s):

Gene Expression ◽

Nucleic Acid ◽

Biofilm Formation ◽

Cold Shock ◽

Xylella Fastidiosa ◽

Cold Shock Protein ◽

Nucleic Acid Binding ◽

Wild Type ◽

Surface Attachment

Bacterial cold shock-domain proteins (CSPs) are conserved nucleic acid binding chaperones that play important roles in stress adaptation and pathogenesis. Csp1 is a temperature-independent cold shock protein homolog in Xylella fastidiosa, a bacterial plant pathogen of grapevine and other economically important crops. Csp1 contributes to stress tolerance and virulence in X. fastidiosa. However, besides general single stranded nucleic acid binding activity, little is known about the specific function(s) of this protein. To further investigate the role(s) of Csp1, we compared phenotypic differences between wild type and a csp1 deletion mutant (Δcsp1). We observed decreases in cellular aggregation and surface attachment with the Δcsp1 strain compared to the wild type. Transmission electron microscopy imaging revealed that Δcsp1 had reduced pili compared to the wild type and complemented strains. The Δcsp1 strain also showed reduced survival after long term growth, in vitro. Since Csp1 binds DNA and RNA, its influence on gene expression was also investigated. Long-read Nanopore RNA-Seq analysis of wild type and Δcsp1 revealed changes in expression of several genes important for attachment and biofilm formation in Δcsp1. One gene of intertest,pilA1, encodes a type IV pili subunit protein and was up regulated in Δcsp1. Deleting pilA1 increased surface attachment in vitro and reduced virulence in grapevines.X. fastidiosa virulence depends on bacterial attachment to host tissue and movement within and between xylem vessels. Our results show Csp1 may play a role in both virulence and stress tolerance by influencing expression of genes important for biofilm formation.

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Efficacy of slightly acidic electrolyzed water on inactivation of Cronobacter sakazakii and biofilm cell

Journal of Food Protection ◽

10.4315/jfp-21-263 ◽

2021 ◽

Author(s):

Han Tao ◽

Qiao-Ming Liao ◽

Yi Xu ◽

Hui-li Wang

Keyword(s):

Gene Expression ◽

Nucleic Acid ◽

Biofilm Formation ◽

Response Regulator ◽

Cronobacter Sakazakii ◽

Cell Integrity ◽

Electronic Microscopy ◽

Sem Images ◽

Electrolyzed Water ◽

Lower Ability

The disinfection efficacy and mechanism of slightly acid electrolyzed water (SAEW) on Cronobacter sakazakii were investigated. SAEW solutions in three concentrations were carried on C. sakazakii which decreased in a range of 23%-55% in 2 minutes. The propidium iodide (PI) uptake and electronic microscopy (SEM) images indicated that SAEW treatment damaged cell integrity and changed membrane permeability with leaking nucleic acid (109.7%), intercellular protein (692.3%) and K + (53.6%). It was accompanied with lower ability of biofilm formation. SAEW treatment reduced the activity of SOD and CAT from 100.73 U/mgprot and 114.18 U/mgprot to 50.03 U/mgprot and 50.13 U/mgprot, respectively. It lowered down the gene expression of response regulator (katG, rpoS, phoP, glpK,dacC and CSK29544_RS05515 ) which made C. sakazakii failed to repair osmotic stress-induced damage and inhibited their biofilm formation. These findings provide an understanding of associations between bacterial genotype and phenotype induced by SAEW.

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Undulatory topographical waves for flow-induced foulant sweeping

Science Advances ◽

10.1126/sciadv.aax8935 ◽

2019 ◽

Vol 5 (11) ◽

pp. eaax8935 ◽

Cited By ~ 5

Author(s):

Hangil Ko ◽

Hyun-Ha Park ◽

Hyeokjun Byeon ◽

Minsu Kang ◽

Jaeha Ryu ◽

...

Keyword(s):

Composite Material ◽

Biofilm Formation ◽

Effective Means ◽

Material Surface ◽

Initial Attachment ◽

Dynamic Motion ◽

New Class ◽

Efficient Suppression ◽

Good Biocompatibility

Diverse bioinspired antifouling strategies have demonstrated effective fouling-resistant properties with good biocompatibility, sustainability, and long-term activity. However, previous studies on bioinspired antifouling materials have mainly focused on material aspects or static architectures of nature without serious consideration of kinetic topographies or dynamic motion. Here, we propose a magnetically responsive multilayered composite that can generate coordinated, undulatory topographical waves with controlled length and time scales as a new class of dynamic antifouling materials. The undulatory surface waves of the dynamic composite induce local and global vortices near the material surface and thereby sweep away foulants from the surface, fundamentally inhibiting their initial attachment. As a result, the dynamic composite material with undulating topographical waves provides an effective means for efficient suppression of biofilm formation without surface modification with chemical moieties or nanoscale architectures.

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Introduction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070266 ◽

1978 ◽

Vol 36 (3) ◽

pp. 543-544

Author(s):

W. Bernard

Keyword(s):

Molecular Weight ◽

Electron Microscope ◽

Nucleic Acid ◽

Gene Mapping ◽

Molecular Genetics ◽

Cell Biology ◽

Gene Activity ◽

Close Connection ◽

Basic Information ◽

Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

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Infection of Escherichia coli with bacteriophages

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063767 ◽

1969 ◽

Vol 27 ◽

pp. 370-371

Author(s):

Manfred E. Bayer

Keyword(s):

Escherichia Coli ◽

Nucleic Acid ◽

Cell Surface ◽

Virus Type ◽

Infection Process ◽

Adsorption Site ◽

The Other ◽

Specific Receptors ◽

Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

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Nucleic Acid Molecules Prepared by Monolayer Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094140 ◽

1972 ◽

Vol 30 ◽

pp. 178-179

Author(s):

Dimitrij Lang

Keyword(s):

Electron Microscopy ◽

Standard Deviation ◽

Nucleic Acid ◽

Cytochrome C ◽

Nucleic Acids ◽

Contour Length ◽

Sample Standard Deviation ◽

Molecular Weights ◽

Length Measurements ◽

Protein Monolayer

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.

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Snapshot blotting: The transfer of nucleic acids and nucleoprotein complexes from electrophoresis gels to EM grids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124215 ◽

1992 ◽

Vol 50 (1) ◽

pp. 762-763

Author(s):

Stephen D. Jett

Keyword(s):

Nucleic Acid ◽

Nucleic Acids ◽

Nucleic Acid Binding ◽

Mobility Shift ◽

Carbon Coated ◽

Nucleoprotein Complexes ◽

Mobility Shift Assay ◽

Protein Nucleic Acid ◽

Gel Mobility Shift ◽

Nucleic Acid Interactions

The electrophoresis gel mobility shift assay is a popular method for the study of protein-nucleic acid interactions. The binding of proteins to DNA is characterized by a reduction in the electrophoretic mobility of the nucleic acid. Binding affinity, stoichiometry, and kinetics can be obtained from such assays; however, it is often desirable to image the various species in the gel bands using TEM. Present methods for isolation of nucleoproteins from gel bands are inefficient and often destroy the native structure of the complexes. We have developed a technique, called “snapshot blotting,” by which nucleic acids and nucleoprotein complexes in electrophoresis gels can be electrophoretically transferred directly onto carbon-coated grids for TEM imaging.

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Bacterial biofilm behavior in water-supply lines of dental units

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124811 ◽

1992 ◽

Vol 50 (1) ◽

pp. 882-883

Author(s):

B.D. Tall ◽

K.S. George ◽

R. T. Gray ◽

H.N. Williams

Keyword(s):

Water Supply ◽

Medical Devices ◽

Biofilm Formation ◽

Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

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