Antimicrobial and Anticorrosion Activity of a Novel Composite Biocide against Mixed Bacterial Strains in Taiwanese Marine Environments

Taiwan is an island with a humid subtropical climate. The relatively warm seawater results in biofouling of the surfaces of marine facilities. Biocide application is a common practice for combating and eliminating adhesive fouling. However, a single type of biocide may have limited antimicrobial effects due to the relatively high microbial diversity in marine environments. Therefore, applying a mixture of various biocides may be necessary. In this study, the antimicrobial and anticorrosion properties of a newly designed composite biocide, namely a combination of thymol and benzyldimethyldodecylammonium chloride, were investigated by applying the biocide to 304 stainless steel substrates immersed in inocula containing bacterial strains from Tamsui and Zuoying harbors. The ability of 3TB and 5TB treatments to prevent sessile cells and biofilm formation on the 304 stainless steel coupon surface was determined through scanning electron microscopy investigation. In addition, confocal laser scanning microscopy indicated that the 5TB treatment achieved a greater bactericidal effect in both the Tamsui and Zuoying inocula. Moreover, electrochemical impedance spectroscopy revealed that the diameter of the Nyquist semicircle was almost completely unaffected by Tamsui or Zuoying under the 5TB treatment. Through these assessments of antimicrobial activity and corrosion resistance, 5TB treatment was demonstrated to have superior bactericidal activity against mixed strains in both southern and northern Taiwanese marine environments.

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Inhibitive Properties of Benzyldimethyldodecylammonium Chloride on Microbial Corrosion of 304 Stainless Steel in a Desulfovibrio desulfuricans-Inoculated Medium

Materials ◽

10.3390/ma12020307 ◽

2019 ◽

Vol 12 (2) ◽

pp. 307 ◽

Cited By ~ 2

Author(s):

Chung-Wen Hsu ◽

Tzu-En Chen ◽

Kai-Yin Lo ◽

Yueh-Lien Lee

Keyword(s):

Stainless Steel ◽

Laser Scanning ◽

Steel Substrate ◽

Desulfovibrio Desulfuricans ◽

Corrosion Current ◽

Laser Scanning Microscopy ◽

304 Stainless Steel ◽

Confocal Laser ◽

Microbial Corrosion ◽

Sulfate Reducing

Biocides are frequently used to control sulfate-reducing bacteria (SRB) in biofouling. The increasing restrictions of environmental regulations and growing safety concerns on the use of biocides result in efforts to minimize the amount of biocide use and develop environmentally friendly biocides. In this study, the antimicrobial activity and corrosion inhibition effect of a low-toxic alternative biocide, benzyldimethyldodecylammonium chloride (BDMDAC), on a 304 stainless steel substrate immersed in a Desulfovibrio desulfuricans (D. desulfuricans)-inoculated medium was examined. Potentiodynamic polarization curves were used to analyze corrosion behavior. Biofilm formation and corrosion products on the surfaces of 304 stainless steel coupons were examined using scanning electron microscopy (SEM), energy-dispersive X-ray spectrum, and confocal laser scanning microscopy (CLSM). Results demonstrated that this compound exhibited satisfactory results against microbial corrosion by D. desulfuricans. The corrosion current density and current densities in the anodic region were lower in the presence of BDMDAC in the D. desulfuricans-inoculated medium. SEM and CLSM analyses revealed that the presence of BDMDAC mitigated formation of biofilm by D. desulfuricans.

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Polymeric Nanoparticles Active against Dual-Species Bacterial Biofilms

Molecules ◽

10.3390/molecules26164958 ◽

2021 ◽

Vol 26 (16) ◽

pp. 4958

Author(s):

Jessa Marie V. Makabenta ◽

Jungmi Park ◽

Cheng-Hsuan Li ◽

Aritra Nath Chattopadhyay ◽

Ahmed Nabawy ◽

...

Keyword(s):

Antimicrobial Activity ◽

Laser Scanning ◽

Polymeric Nanoparticles ◽

Bacterial Species ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Bacterial Biofilms ◽

Global Public Health ◽

Bacterial Strains

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. Broad-spectrum antimicrobial activity was observed, with reduction in both bacterial viability and overall biofilm mass. Further, PNPs displayed minimal fibroblast toxicity and high antimicrobial activity in an in vitro co-culture model comprising fibroblast cells and dual-species biofilms of Escherichia coli and Pseudomonas aeruginosa. This study highlights a potential clinical application of the presented polymeric platform.

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The Interaction of N-Acetylcysteine and Serum Transferrin Promotes Bacterial Biofilm Formation

Cellular Physiology and Biochemistry ◽

10.1159/000487566 ◽

2018 ◽

Vol 45 (4) ◽

pp. 1399-1409 ◽

Cited By ~ 7

Author(s):

Supeng Yin ◽

Bei Jiang ◽

Guangtao Huang ◽

Yulong Zhang ◽

Bo You ◽

...

Keyword(s):

Human Serum ◽

Biofilm Formation ◽

Laser Scanning ◽

Serum Proteins ◽

Venous Catheter ◽

Bacterial Biofilm ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Bacterial Strains

Background/Aims: N-acetylcysteine (NAC) is a novel and promising agent with activity against bacterial biofilms. Human serum also inhibits biofilm formation by some bacteria. We tested whether the combination of NAC and human serum offers greater anti-biofilm activity than either agent alone. Methods: Microtiter plate assays and confocal laser scanning microscopy were used to evaluate bacterial biofilm formation in the presence of NAC and human serum. qPCR was used to examine expression of selected biofilm-associated genes. Extracellular matrix (ECM) was observed by transmission electron microscopy. The antioxidants GSH or ascorbic acid were used to replace NAC, and human transferrin, lactoferrin, or bovine serum albumin were used to replace serum proteins in biofilm formation assays. A rat central venous catheter model was developed to evaluate the effect of NAC on biofilm formation in vivo. Results: NAC and serum together increased biofilm formation by seven different bacterial strains. In Staphylococcus aureus, expression of genes for some global regulators and for genes in the ica-dependent pathway increased markedly. In Pseudomonas aeruginosa, transcription of las, the PQS quorum sensing (QS) systems, and the two-component system GacS/GacA increased significantly. ECM production by S. aureus and P. aeruginosa was also enhanced. The potentiation of biofilm formation is due mainly to interaction between NAC and transferrin. Intravenous administration of NAC increased colonization by S. aureus and P. aeruginosa on implanted catheters. Conclusions: NAC used intravenously or in the presence of blood increases bacterial biofilm formation rather than inhibits it.

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Influence of the Electrolyte Composition on the Corrosion Behavior of Anodized AZ31B Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1012.424 ◽

2020 ◽

Vol 1012 ◽

pp. 424-429

Author(s):

Leandro Antonio de Oliveira ◽

Renato Altobelli Antunes

Keyword(s):

Magnesium Alloy ◽

Laser Scanning ◽

Electrochemical Impedance ◽

Electrolyte Composition ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Mixed Solution ◽

Protective Properties ◽

Az31b Magnesium Alloy ◽

Substrate Dissolution

Investigations have been performed to study the effects of the electrolyte composition on the properties of anodized films grown on AZ31B magnesium alloy. The corrosion protection ability of the oxide layers was explored by using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy. Film morphology was examined by scanning electron microscopy and confocal laser scanning microscopy. In spite of its higher roughness average, the film formed in the silicate and hydroxide mixed solution enhanced the protective properties of the anodized layer, thus reducing the substrate dissolution rate.

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Characterisation of electrochemical immunosensor for detection of viable not-culturable forms of Legionellla pneumophila in water samples

Chemical Papers ◽

10.1515/chempap-2015-0170 ◽

2015 ◽

Vol 69 (11) ◽

Cited By ~ 7

Author(s):

Dejla Sboui ◽

Mina Souiri ◽

Stephanie Reynaud ◽

Sabine Palle ◽

Manel Ben Ismail ◽

...

Keyword(s):

Legionella Pneumophila ◽

Indium Tin Oxide ◽

Membrane Filtration ◽

Laser Scanning ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Angle Measurement ◽

Electrochemical Immunosensor ◽

Laser Scanning Microscopy ◽

Confocal Laser

AbstractLegionella pneumophila may cause a fatal pneumonia in humans known as Legionnaires’ disease (LD). The strategies of L. pneumophila to adapt to and resist stressful environmental conditions include the ability to enter into a VBNC (viable but not culturable) state. The detection of L. pneumophila in environmental samples benefits from the use of standardised methods: for detection and enumeration following membrane filtration (AFNOR T90-431, ISO 11731) and detection and quantification by polymerase chain reaction PCR (AFNOR T90-471, ISO 12869). Culture is hampered by its inability to detect VBNC forms and PCR is unable to discriminate between live and dead bacteria. The present immunosensor was obtained by the immobilisation of a monoclonal anti-L. pneumophila antibody (MAb) on an indium-tin oxide (ITO) electrode by the self-assembled monolayers (SAMs) method using an aminosilane. The immunosensor was characterised by wettability (contact angle measurement), atomic force microscopy (AFM), confocal laser scanning microscopy (CLSM), and electrochemical impedance spectroscopy (EIS). A limit of detection of 10 bacteria per mL was observed on artificial samples.

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Organo-Selenium-Containing Polyester Bandage Inhibits Bacterial Biofilm Growth on the Bandage and in the Wound

Biomedicines ◽

10.3390/biomedicines8030062 ◽

2020 ◽

Vol 8 (3) ◽

pp. 62

Author(s):

Phat Tran ◽

Tyler Enos ◽

Keaton Luth ◽

Abdul Hamood ◽

Coby Ray ◽

...

Keyword(s):

Wound Infection ◽

Wound Dressing ◽

Laser Scanning ◽

Bacterial Biofilm ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Bacterial Strains ◽

Biofilm Growth ◽

Biofilm Model

The dressing material of a wound plays a key role since bacteria can live in the bandage and keep re-infecting the wound, thus a bandage is needed that blocks biofilm in the bandage. Using an in vivo wound biofilm model, we examined the effectiveness of an organo-selenium (OS)-coated polyester dressing to inhibit the growth of bacteria in a wound. Staphylococcus aureus (as well as MRSA, Methicillin resistant Staph aureus), Stenotrophomonas maltophilia, Enterococcus faecalis, Staphylococcus epidermidis, and Pseudomonas aeruginosa were chosen for the wound infection study. All the bacteria were enumerated in the wound dressing and in the wound tissue under the dressing. Using colony-forming unit (CFU) assays, over 7 logs of inhibition (100%) was found for all the bacterial strains on the material of the OS-coated wound dressing and in the tissue under that dressing. Confocal laser scanning microscopy along with IVIS spectrum in vivo imaging confirmed the CFU results. Thus, the dressing acts as a reservoir for a biofilm, which causes wound infection. The same results were obtained after soaking the dressing in PBS at 37 °C for three months before use. These results suggest that an OS coating on polyester dressing is both effective and durable in blocking wound infection.

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Finding the comfort zone: Online-monitoring of electroactive bacteria colonising electrode surfaces with different chemical properties

10.5194/biofilms9-46 ◽

2020 ◽

Author(s):

Hanna Frühauf ◽

Markus Stöckl ◽

Dirk Holtmann

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Confocal Laser Scanning Microscopy ◽

Electrode Surface ◽

Biofilm Formation ◽

Laser Scanning ◽

Electrochemical Impedance ◽

Flow Cell ◽

Laser Scanning Microscopy ◽

Confocal Laser

Mechanisms of electron transfer vary greatly within the diverse group of electroactive microorganisms and so does the need to attach to the electrode surface, e.g. by forming a biofilm. Electrochemical impedance spectroscopy (EIS) and confocal laser scanning microscopy (CLSM) are well established methods to monitor cell attachment to an electrode surface and have therefore been combined in a flow cell as a screening system. The flow cell, equipped with a transparent indium tin oxide working electrode (ITO WE), allows monitoring of attachment processes in real time with minimal needs for additional biofilm preparation. In preliminary experiments the flow cell was successfully used as microbial fuel cell (MFC) with a potential of +0.4 V vs. Ag/AgCl using Shewanella oneidensis as electroactive model organism. [1] Commonly, graphite-based electrode materials are used in bioelectrochemical systems due to their low costs and high conductivity. However, the hydrophobic and negatively charged surface is not yet optimal for microbial attachment. There are numerous attempts on electrode surface engineering in order to overcome this problem. In the majority of studies the biofilm analysis and evaluation of the attachment takes place at the end of the experiment, neglecting the impacts of the chemical surface properties and initial electrode conditioning during the very beginning of biofilm formation. To investigate initial attachment and biofilm formation in real-time, the transparent ITO-electrode is coated with polyelectrolytes differing in hydrophobicity and polarity to evaluate their effects on the initial surface colonisation by different electroactive microorganisms. Combining CLSM and EIS, both, surface coverage and electrochemical interaction of electrode-associated bacteria can be assessed. With this we aim to understand and ease initial steps of biofilm formation to improve efficiency of bioelectrochemical applications, e.g. with regards to start-up time. &#160; [1] St&#246;ckl, M., Schlegel, C., Sydow, A., Holtmann, D., Ulber, R., & Mangold, K. M. (2016). Membrane separated flow cell for parallelized electrochemical impedance spectroscopy and confocal laser scanning microscopy to characterize electro-active microorganisms.&#160;Electrochimica Acta,&#160;220, 444-452.

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A Novel Hybrid Peptide Composed of LfcinB6 and KR-12-a4 With Enhanced Antimicrobial, Anti-Inflammatory and Anti-Biofilm Activities

10.21203/rs.3.rs-1109468/v1 ◽

2021 ◽

Author(s):

Chelladurai Ajish ◽

Sungtae Yang ◽

S. Dinesh Kumar ◽

Eun Young Kim ◽

Hye Jung Min ◽

...

Keyword(s):

Antimicrobial Activity ◽

Laser Scanning ◽

Antimicrobial Agents ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Bacterial Cells ◽

Bacterial Strains ◽

Hybrid Peptide ◽

Cell Selectivity ◽

Anti Inflammatory

Abstract Hybridizing two known antimicrobial peptides (AMPs) is a simple and effective strategy for designing antimicrobial agents with enhanced cell selectivity against bacterial cells. Here, we generated a hybrid peptide Lf-KR in which LfcinB6 and KR-12-a4 were linked with a Pro hinge to obtain a novel AMP with potent antimicrobial, anti-inflammatory, and anti-biofilm activities. Lf-KR exerted superior cell selectivity for bacterial cells over sheep red blood cells. Lf-KR showed broad-spectrum antimicrobial activities (MIC: 4–8 mM) against tested 12 bacterial strains and retained its antimicrobial activity in the presence of salts at physiological concentrations. Membrane depolarization and dye leakage assays showed that the enhanced antimicrobial activity of Lf-KR was due to increased permeabilization and depolarization of microbial membranes. Lf-KR significantly inhibited the expression and production of pro-inflammatory cytokines (NO and TNF-a) in LPS-stimulated mouse macrophage RAW264.7 cells. In addition, Lf-KR showed a powerful eradication effect on preformed multidrug-resistant Pseudomonas aeruginosa (MDRPA) biofilms. We confirmed using confocal laser scanning microscopy that a large portion of the preformed MDRPA biofilm structure was perturbed by the addition of Lf-KR. Collectively, our results suggest that Lf-KR can be an antimicrobial, anti-inflammatory, and anti-biofilm candidate as a pharmaceutical agent.

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Electrochemical and surface analytical techniques applied to microbiologically influenced corrosion investigation

Corrosion Reviews ◽

10.1515/corrrev-2017-0032 ◽

2018 ◽

Vol 36 (4) ◽

pp. 349-363 ◽

Cited By ~ 4

Author(s):

László Trif ◽

Abdul Shaban ◽

Judit Telegdi

Keyword(s):

Photoelectron Spectroscopy ◽

Laser Scanning ◽

Electrochemical Impedance ◽

Electrochemical Techniques ◽

Analytical Techniques ◽

Laser Scanning Microscopy ◽

Microbiologically Influenced Corrosion ◽

Microbial Consortia ◽

Confocal Laser ◽

The Impact

AbstractSuitable application of techniques for detection and monitoring of microbiologically influenced corrosion (MIC) is crucial for understanding the mechanisms of the interactions and for selecting inhibition and control approaches. This paper presents a review of the application of electrochemical and surface analytical techniques in studying the MIC process of metals and their alloys. Conventional electrochemical techniques, such as corrosion potential (Ecorr), redox potential, dual-cell technique, polarization curves, electrochemical impedance spectroscopy (EIS), electrochemical noise (EN) analysis, and microelectrode techniques, are discussed, with examples of their use in various MIC studies. Electrochemical quartz crystal microbalance, which is newly used in MIC study, is also discussed. Microscopic techniques [scanning electron microscopy (SEM), environmental SEM (ESEM), atomic force microscopy (AFM), confocal laser microscopy (CLM), confocal laser scanning microscopy (CLSM), confocal Raman microscopy] and spectroscopic analytical methods [Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS)] are also highlighted. This review highlights the heterogeneous characteristics of microbial consortia and use of special techniques to study their probable effects on the metal substrata. The aim of this review is to motivate using a combination of new procedures for research and practical measurement and calculation of the impact of MIC and biofilms on metals and their alloys.

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Culture and Detection of Campylobacter jejuni within Mixed Microbial Populations of Biofilms on Stainless Steel

Journal of Food Protection ◽

10.4315/0362-028x-70.6.1379 ◽

2007 ◽

Vol 70 (6) ◽

pp. 1379-1385 ◽

Cited By ~ 49

Author(s):

SHERIASE Q. SANDERS ◽

DOROTHY H. BOOTHE ◽

JOSEPH F. FRANK ◽

JUDY W. ARNOLD

Keyword(s):

Stainless Steel ◽

Campylobacter Jejuni ◽

Laser Scanning ◽

The United States ◽

Laser Scanning Microscopy ◽

Epifluorescence Microscopy ◽

Confocal Laser ◽

Atmospheric Conditions ◽

Culture Methods ◽

Bacterial Populations

Campylobacter jejuni is the most frequently reported cause of foodborne illness in the United States, but its survival outside the host is poor. The objective of this research was to examine the formation and composition of biofilms by C. jejuni alone and within mixed bacterial populations from the poultry-processing environment. C. jejuni growth was assessed with four media, two temperatures, and two atmospheric conditions to develop culture methods for liquid media that would allow growth within the biofilms. Growth kinetics was followed at four cell densities to determine temporal compatibility within biofilm mixtures. Analysis of the biofilms by confocal laser scanning microscopy showed that C. jejuni formed a biofilm when incubated without other bacteria. The average surface area of stainless steel covered by C. jejuni increased by 50% from 24 to 48 h, remained level to 96 h, and then decreased by 88% by 168 h. C. jejuni and mixed bacterial populations formed biofilms during incubation periods of up to 7 days. The area of the mixture was significantly greater than for C. jejuni alone at 24 h, was approximately the same at 48 h, and was significantly less by 168 h. When incubated with either of two initial inoculum densities of other bacteria, the number of C. jejuni was enhanced after 24 h. The intensity of fluorescence and cell viability were monitored by epifluorescence microscopy. This study provides the basis for studying interactions of Campylobacter spp. with other bacteria in the environment, which will aid in the design of effective intervention strategies.

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