Antimicrobial effects of airborne acoustic ultrasound and plasma activated water from cold and thermal plasma systems on biofilms

Abstract Bacterial biofilms are difficult to inactivate due to their high antimicrobial resistance. Therefore, new approaches are required for more effective bacterial biofilm inactivation. Airborne acoustic ultrasound improves bactericidal or bacteriostatic activity which is safe and environmentally friendly. While, plasma activated water (PAW) is attracting increasing attention due to its strong antimicrobial properties. This study determined efficacy of combined airborne acoustic ultrasound and plasma activated water from both cold and thermal plasma systems in inactivating Escherichia coli K12 biofilms. The application of airborne acoustic ultrasound (15 min) alone was significantly more effective in reducing E. coli counts in 48 and 72 h biofilms compared to 30 min treatment with PAW. The effect of airborne acoustic ultrasound was more pronounced when used in combination with PAW. Airborne acoustic ultrasound treatment for 15 min of the E. coli biofilm followed by treatment with PAW significantly reduced the bacterial count by 2.2—2.62 Log10 CFU/mL when compared to control biofilm treated with distilled water. This study demonstrates that the synergistic effects of airborne acoustic ultrasound and PAW for enhanced antimicrobial effects. These technologies have the potential to prevent and control biofilm formation in food and bio-medical applications.

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Antimicrobial Activity and Prevention of Bacterial Biofilm Formation of Silver and Zinc Oxide Nanoparticle-Containing Polyester Surfaces at Various Concentrations for Use

Foods ◽

10.3390/foods9040442 ◽

2020 ◽

Vol 9 (4) ◽

pp. 442 ◽

Cited By ~ 3

Author(s):

Fabio Fontecha-Umaña ◽

Abel Guillermo Ríos-Castillo ◽

Carolina Ripolles-Avila ◽

José Juan Rodríguez-Jerez

Keyword(s):

Antimicrobial Activity ◽

Zinc Oxide ◽

Biofilm Formation ◽

Antimicrobial Properties ◽

Bacterial Biofilm ◽

Antimicrobial Efficacy ◽

Ag Nps ◽

Zno Nps ◽

E Coli ◽

Food Contact Surfaces

Food contact surfaces are primary sources of bacterial contamination in food industry processes. With the objective of preventing bacterial adhesion and biofilm formation on surfaces, this study evaluated the antimicrobial activity of silver (Ag-NPs) and zinc oxide (ZnO-NPs) nanoparticle-containing polyester surfaces (concentration range from 400 ppm to 850 ppm) using two kinds of bacteria, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli), and the prevention of bacterial biofilm formation using the pathogen Listeria monocytogenes. The results of antimicrobial efficacy (reductions ≥ 2 log CFU/cm2) showed that at a concentration of 850 ppm, ZnO-NPs were effective against only E. coli (2.07 log CFU/cm2). However, a concentration of 400 ppm of Ag-NPs was effective against E. coli (4.90 log CFU/cm2) and S. aureus (3.84 log CFU/cm2). Furthermore, a combined concentration of 850 ppm Ag-NPs and 400 ppm ZnO-NPs showed high antimicrobial efficacy against E. coli (5.80 log CFU/cm2) and S. aureus (4.11 log CFU/cm2). The results also showed a high correlation between concentration levels and the bacterial activity of Ag–ZnO-NPs (R2 = 0.97 for S. aureus, and R2 = 0.99 for E. coli). They also showed that unlike individual action, the joint action of Ag-NPs and ZnO-NPs has high antimicrobial efficacy for both types of microorganisms. Moreover, Ag-NPs prevent the biofilm formation of L. monocytogenes in humid conditions of growth at concentrations of 500 ppm. Additional studies under different conditions are needed to test the durability of nanoparticle containing polyester surfaces with antimicrobial properties to optimize their use.

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More than Enzymes That Make or Break Cyclic Di-GMP—Local Signaling in the Interactome of GGDEF/EAL Domain Proteins of Escherichia coli

mBio ◽

10.1128/mbio.01639-17 ◽

2017 ◽

Vol 8 (5) ◽

Cited By ~ 60

Author(s):

Olga Sarenko ◽

Gisela Klauck ◽

Franziska M. Wilke ◽

Vanessa Pfiffer ◽

Anja M. Richter ◽

...

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Second Messenger ◽

Bacterial Biofilm ◽

Interaction Patterns ◽

Systematic Analysis ◽

E Coli ◽

Diguanylate Cyclases ◽

Hub Proteins ◽

Effector Target

ABSTRACT The bacterial second messenger bis-(3′-5′)-cyclic diguanosine monophosphate (c-di-GMP) ubiquitously promotes bacterial biofilm formation. Intracellular pools of c-di-GMP seem to be dynamically negotiated by diguanylate cyclases (DGCs, with GGDEF domains) and specific phosphodiesterases (PDEs, with EAL or HD-GYP domains). Most bacterial species possess multiple DGCs and PDEs, often with surprisingly distinct and specific output functions. One explanation for such specificity is “local” c-di-GMP signaling, which is believed to involve direct interactions between specific DGC/PDE pairs and c-di-GMP-binding effector/target systems. Here we present a systematic analysis of direct protein interactions among all 29 GGDEF/EAL domain proteins of Escherichia coli . Since the effects of interactions depend on coexpression and stoichiometries, cellular levels of all GGDEF/EAL domain proteins were also quantified and found to vary dynamically along the growth cycle. Instead of detecting specific pairs of interacting DGCs and PDEs, we discovered a tightly interconnected protein network of a specific subset or “supermodule” of DGCs and PDEs with a coregulated core of five hyperconnected hub proteins. These include the DGC/PDE proteins representing the c-di-GMP switch that turns on biofilm matrix production in E. coli . Mutants lacking these core hub proteins show drastic biofilm-related phenotypes but no changes in cellular c-di-GMP levels. Overall, our results provide the basis for a novel model of local c-di-GMP signaling in which a single strongly expressed master PDE, PdeH, dynamically eradicates global effects of several DGCs by strongly draining the global c-di-GMP pool and thereby restricting these DGCs to serving as local c-di-GMP sources that activate specific colocalized effector/target systems. IMPORTANCE c-di-GMP signaling in bacteria is believed to occur via changes in cellular c-di-GMP levels controlled by antagonistic and potentially interacting pairs of diguanylate cyclases (DGCs) and c-di-GMP phosphodiesterases (PDEs). Our systematic analysis of protein-protein interaction patterns of all 29 GGDEF/EAL domain proteins of E. coli , together with our measurements of cellular c-di-GMP levels, challenges both aspects of this current concept. Knocking out distinct DGCs and PDEs has drastic effects on E. coli biofilm formation without changing the cellular c-di-GMP level. In addition, rather than generally coming in interacting DGC/PDE pairs, a subset of DGCs and PDEs operates as central interaction hubs in a larger "supermodule," with other DGCs and PDEs behaving as “lonely players” without contacts to other c-di-GMP-related enzymes. On the basis of these data, we propose a novel concept of “local” c-di-GMP signaling in bacteria with multiple enzymes that make or break the second messenger c-di-GMP.

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Chaperones mainly suppress primary nucleation during formation of functional amyloid required for bacterial biofilm formation

Chemical Science ◽

10.1039/d1sc05790a ◽

2022 ◽

Author(s):

Madhu Nagaraj ◽

Zahra Najarzadeh ◽

Jonathan Pansieri ◽

Ludmilla A. Morozova-Roche ◽

Henrik Biverstål ◽

...

Keyword(s):

Neurodegenerative Diseases ◽

Biofilm Formation ◽

Bacterial Biofilm ◽

Functional Amyloid ◽

E Coli ◽

Primary Nucleation ◽

Functional Amyloids

Unlike misfolding in neurodegenerative diseases, aggregation of functional amyloids involved in bacterial biofilm, e.g. CsgA (E. coli) and FapC (Pseudomonas), is carefully regulated. However, it is unclear whether functional aggregation...

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RNase I regulates Escherichia coli 2′,3′-cyclic nucleotide monophosphate levels and biofilm formation

Biochemical Journal ◽

10.1042/bcj20170906 ◽

2018 ◽

Vol 475 (8) ◽

pp. 1491-1506 ◽

Cited By ~ 8

Author(s):

Benjamin M. Fontaine ◽

Kevin S. Martin ◽

Jennifer M. Garcia-Rodriguez ◽

Claire Jung ◽

Laura Briggs ◽

...

Keyword(s):

Escherichia Coli ◽

Dna Replication ◽

Cyclic Nucleotide ◽

Biofilm Formation ◽

Physiological Role ◽

Rna Degradation ◽

Bacterial Biofilm ◽

Biological Functions ◽

Salvage Pathway ◽

E Coli

Regulation of nucleotide and nucleoside concentrations is critical for faithful DNA replication, transcription, and translation in all organisms, and has been linked to bacterial biofilm formation. Unusual 2′,3′-cyclic nucleotide monophosphates (2′,3′-cNMPs) recently were quantified in mammalian systems, and previous reports have linked these nucleotides to cellular stress and damage in eukaryotes, suggesting an intriguing connection with nucleotide/nucleoside pools and/or cyclic nucleotide signaling. This work reports the first quantification of 2′,3′-cNMPs in Escherichia coli and demonstrates that 2′,3′-cNMP levels in E. coli are generated specifically from RNase I-catalyzed RNA degradation, presumably as part of a previously unidentified nucleotide salvage pathway. Furthermore, RNase I and 2′,3′-cNMP levels are demonstrated to play an important role in controlling biofilm formation. This work identifies a physiological role for cytoplasmic RNase I and constitutes the first progress toward elucidating the biological functions of bacterial 2′,3′-cNMPs.

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Disrupting Irreversible Bacterial Adhesion and Biofilm Formation with an Engineered Enzyme

Applied and Environmental Microbiology ◽

10.1128/aem.00265-21 ◽

2021 ◽

Author(s):

Holly M. Mayton ◽

Sharon L. Walker ◽

Bryan W. Berger

Keyword(s):

Listeria Monocytogenes ◽

Bacterial Adhesion ◽

Biofilm Formation ◽

Glycosyl Hydrolase ◽

Cell Surface Hydrophobicity ◽

Bacterial Biofilm ◽

Enzyme Treatment ◽

E Coli ◽

Initial Adhesion ◽

The Impact

Biofilm formation is often attributed to post-harvest bacteria persistence on fresh produce and food handling surfaces. In this study, a predicted glycosyl hydrolase enzyme was expressed, purified and validated for removal of microbial biofilms from biotic and abiotic surfaces under conditions used for chemical cleaning agents. Crystal violet biofilm staining assays revealed that 0.1 mg/mL of enzyme inhibited up to 41% of biofilm formation by E. coli O157:H7, E. coli 25922, Salmonella Typhimurium, and Listeria monocytogenes. Further, the enzyme was effective at removing mature biofilms, providing a 35% improvement over rinsing with a saline solution alone. Additionally, a parallel-plate flow cell was used to directly observe and quantify the impact of enzyme rinses on E. coli O157:H7 cells adhered to spinach leaf surfaces. The presence of 1 mg/L enzyme resulted in nearly 6 times greater detachment rate coefficients than a DI water rinse, while the total cells removed from the surface increased from 10% to 25% over the 30 minute rinse time, reversing the initial phases of biofilm formation. Enzyme treatment of all 4 cell types resulted in significantly reduced cell surface hydrophobicity, and collapse of negatively stained E. coli 25922 cells imaged by electron microscopy, suggesting potential polysaccharide surface modification of enzyme-treated bacteria. Collectively, these results point to the broad substrate specificity and robustness of the enzyme to different types of biofilm stages, solution conditions and pathogen biofilm types, and may be useful as a method for removal or inhibition of bacterial biofilm formation. IMPORTANCE In this study, the ability of an engineered enzyme to reduce bacterial adhesion and biofilm formation of several foodborne pathogens was demonstrated, representing a promising option for enhancing or replacing chlorine and other chemical sanitizers in food processing applications. Specifically, significant reductions of the pathogens Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes biofilms are observed, as well as reduction in initial adhesion. Enzymes have the added benefits of being green, sustainable alternatives to chemical sanitizers, as well as having minimal impact on food properties, in contrast with many alternative antimicrobial options such as bleach that aim to minimize food safety risks.

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In-Vitro Evaluation of Biological Activity of New Series of 1, 3, 4-Oxadiazole Derivatives Against Bap Gene Expression in Acinetobacter bumanni Biofilm

Gene Cell and Tissue ◽

10.5812/gct.111894 ◽

2021 ◽

Vol In Press (In Press) ◽

Author(s):

Sedigheh Akbarnezhad Ghareh Lar ◽

Nakisa Zarrabi Ahrabi ◽

Yasin SarveAhrabi

Keyword(s):

Biofilm Formation ◽

Functional Group ◽

Biological Activities ◽

Antimicrobial Properties ◽

Housekeeping Gene ◽

Bacterial Biofilm ◽

Wide Range ◽

Oxadiazole Derivatives ◽

The Impact

Background: Acinetobacter bumanni is one of the most common opportunistic pathogens in health centers that is resistant to many antibiotics due to biofilm production. 1, 3, 4-oxadiazoles have a wide range of biological activities. Objectives: The aim of this research was to examine the impact of new 1, 3, 4-oxadiazole derivatives on the expression of biofilm-associated surface protein (Bap), playing an important role in promoting the biofilm formation ability of A. baumannii strains. Methods: Derivatives of 1, 3, 4-oxadiazole were synthesized through a one-step synthesis. A. baumannii strains were identified and isolated in the laboratory. The antimicrobial properties of the synthesized materials against the isolated strains were investigated. DNA, RNA, and cDNA were extracted, and the relative expression of BAP gene in A. baumannii isolates was evaluated by real-time polymerase chain reaction. Results: The compound with methoxyphenyl functional group with MIC = 62.50 mg/mL had the best inhibitory performance among all derivatives. Also, the combination of 4i reduced the expression of the Bap gene by about 24 times, but it had no effect on the expression of the 16srRNA housekeeping gene. Conclusions: 1, 3, 4-oxadiazole derivatives, especially the methoxyphenyl functional group, act as an inhibitor of bacterial biofilm formation and have the potential to be used in the pharmaceutical and biological industries.

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Copper Surfaces in Biofilm Control

Nanomaterials ◽

10.3390/nano10122491 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2491

Author(s):

Inês B. Gomes ◽

Manuel Simões ◽

Lúcia C. Simões

Keyword(s):

Biofilm Formation ◽

Copper Alloys ◽

Antimicrobial Properties ◽

Complete Control ◽

Medical Settings ◽

Copper Surfaces ◽

Plumbing Systems ◽

Adverse Environmental Conditions ◽

Negative Impacts ◽

And Control

Biofilms are structures comprising microorganisms associated to surfaces and enclosed by an extracellular polymeric matrix produced by the colonizer cells. These structures protect microorganisms from adverse environmental conditions. Biofilms are typically associated with several negative impacts for health and industries and no effective strategy for their complete control/eradication has been identified so far. The antimicrobial properties of copper are well recognized among the scientific community, which increased their interest for the use of these materials in different applications. In this review the use of different copper materials (copper, copper alloys, nanoparticles and copper-based coatings) in medical settings, industrial equipment and plumbing systems will be discussed considering their potential to prevent and control biofilm formation. Particular attention is given to the mode of action of copper materials. The putative impact of copper materials in the health and/or products quality is reviewed taking into account their main use and the possible effects on the spread of antimicrobial resistance.

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An antimicrobial polycationic sand filter for water disinfection

Water Science & Technology ◽

10.2166/wst.2011.440 ◽

2011 ◽

Vol 63 (9) ◽

pp. 1997-2003 ◽

Cited By ~ 7

Author(s):

Annalisa Onnis-Hayden ◽

Bryan B. Hsu ◽

Alexander M. Klibanov ◽

April Z. Gu

Keyword(s):

Treatment Plant ◽

Antimicrobial Properties ◽

Bacterial Count ◽

Water Disinfection ◽

Aqueous Sample ◽

Secondary Effluent ◽

E Coli ◽

Log Reduction ◽

Disinfection Process ◽

Aqueous Effluent

A new sand filtration water disinfection technology is developed which relies on the antimicrobial properties of hydrophobic polycations (N-hexylated polyethylenimine) covalently attached to the sand's surface. The efficacy of the filter disinfection process was evaluated both with water spiked with E. coli and with real aqueous effluent from a wastewater treatment plant. For the former, over 7-log reduction in bacterial count was achieved. With real environmental wastewater secondary effluent samples, the E. coli concentration reduction declined to under 2 logs. This reduced inactivation efficiency compared to the model aqueous sample is likely due to the particulate or colloidal matter present that diminishes the contact between the immobilized polycation and the suspended bacteria. Preliminary sand washing methods were tested to assess potential ‘regeneration’ approaches. Potential advantages of the proposed approach over conventional disinfection in terms of eliminating harmful by-products and reducing energy consumption are discussed.

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Gene Expression Regulation by the Curli Activator CsgD Protein: Modulation of Cellulose Biosynthesis and Control of Negative Determinants for Microbial Adhesion

Journal of Bacteriology ◽

10.1128/jb.188.6.2027-2037.2006 ◽

2006 ◽

Vol 188 (6) ◽

pp. 2027-2037 ◽

Cited By ~ 83

Author(s):

Eva Brombacher ◽

Andrea Baratto ◽

Corinne Dorel ◽

Paolo Landini

Keyword(s):

Biofilm Formation ◽

Gene Expression Regulation ◽

Constitutive Expression ◽

Cell Aggregation ◽

Negative Regulator ◽

Cellulose Biosynthesis ◽

Transcription Activator ◽

E Coli ◽

Genes Encoding ◽

And Control

ABSTRACT Curli fibers, encoded by the csgBAC genes, promote biofilm formation in Escherichia coli and other enterobacteria. Curli production is dependent on the CsgD transcription activator, which also promotes cellulose biosynthesis. In this study, we investigated the effects of CsgD expression from a weak constitutive promoter in the biofilm formation-deficient PHL565 strain of E. coli. We found that despite its function as a transcription activator, the CsgD protein is localized in the cytoplasmic membrane. Constitutive CsgD expression promotes biofilm formation by PHL565 and activates transcription from the csgBAC promoter; however, csgBAC expression remains dependent on temperature and the growth medium. Constitutive expression of the CsgD protein results in altered transcription patterns for at least 24 novel genes, in addition to the previously identified CsgD-dependent genes. The cspA and fecR genes, encoding regulatory proteins responding to cold shock and to iron, respectively, and yoaD, encoding a putative negative regulator of cellulose biosynthesis, were found to be some of the novel CsgD-regulated genes. Consistent with the predicted functional role, increased expression of the yoaD gene negatively affects cell aggregation, while yoaD inactivation results in stimulation of cell aggregation and leads to increased cellulose production. Inactivation of fecR results in significant increases in both cell aggregation and biofilm formation, while the effects of cspA are not as strong in the conditions tested. Our results indicate that CsgD can modulate cellulose biosynthesis through activation of the yoaD gene. In addition, the positive effect of CsgD on biofilm formation might be enhanced by repression of the fecR gene.

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The Effect of Controlled-release Chlorine Dioxide on the Preservation of Grapefruit

HortScience ◽

10.21273/hortsci11363-16 ◽

2017 ◽

Vol 52 (1) ◽

pp. 122-126 ◽

Cited By ~ 4

Author(s):

Xiuxiu Sun ◽

Elizabeth Baldwin ◽

Chris Ference ◽

Jan Narciso ◽

Anne Plotto ◽

...

Keyword(s):

Controlled Release ◽

Chlorine Dioxide ◽

Slow Release ◽

Standard Dose ◽

Bacterial Count ◽

Citrus Canker ◽

E Coli ◽

Colony Forming Units ◽

And Control ◽

Fast Release

The effect of controlled-release chlorine dioxide (ClO2) gas on the safety and quality of grapefruit was studied. The experiments were run under controlled chamber systems with inoculated fruit, and in boxed fruit under commercial conditions. For the inoculation test, fruit artificially inoculated with either Escherichia coli or Penicillium digitatum, or naturally inoculated Xanthomonas citri ssp. citri (Xcc) (fruits with citrus canker lesions), were incubated in a chamber containing a dose equivalent to 0–60 mg·L−1 of pure ClO2 as an antimicrobial agent. After 24 hours, the microbial population on treated grapefruit was significantly reduced compared with that of control fruit: a dosage of 5 mg·L−1 completely inhibit the growth of E. coli and P. digitatum, but a dosage of 60 mg·L−1 was needed to completely kill Xcc. For the simulated commercial experiment, fruit were harvested in late Oct. 2015 passed through a commercial packing line, and packed in 29 L citrus boxes. ClO2 packets were attached to the top lids with the following five treatments: fast-release, slow-release, slow/fast-release combination (each containing 14.5 mg·L−1 of pure ClO2), double dose fast-release (containing 29 mg·L−1 of ClO2), and control. After 6 weeks of storage at 10 °C (to simulate storage and transportation) + 1 week of storage at 20 °C (to simulate retail marketing), the fruit quality was evaluated. The slow-release treatment at standard dose exhibited the best antimicrobial activity, reducing total aerobic bacterial count and yeast/mold count by 0.95 and 0.94 log colony-forming units (cfu)/g of fruit, respectively, and maintained the best visual, sensory, and overall quality. However, the higher dosage treatments resulted in phytotoxicity as evidenced by peel browning.

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