Antimicrobial and biofilm-disrupting nanostructured TiO2 coating demonstrating photoactivity and dark activity

2021 ◽  
Vol 368 (7) ◽  
Author(s):  
Alibe Wasa ◽  
Johann G Land ◽  
Rukmini Gorthy ◽  
Susan Krumdieck ◽  
Catherine Bishop ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Stainless Steel ◽  
Surface Coating ◽  
Biofilm Formation ◽  
Antimicrobial Materials ◽  
Antimicrobial Material ◽  
Scanning Electron

ABSTRACT Antimicrobial materials are tools used to reduce the transmission of infectious microorganisms. Photo-illuminated titania (TiO2) is a known antimicrobial material. Used as a coating on door handles and similar surfaces, it may reduce viability and colonization by pathogens and limit their spread. We tested the survival of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Saccharomyces cerevisiae on a nano-structured TiO2-based thin film, called ‘NsARC’, and on stainless steel under a variety of light wavelengths and intensities. There was significantly less survival (P <0.001) of all the organisms tested on NsARC compared to inert uncoated stainless steel under all conditions. NsARC was active in the dark and possible mechanisms for this are suggested. NsARC inhibited biofilm formation as confirmed by scanning electron microscopy. These results suggest that NsARC can be used as a self-cleaning and self-sterilizing antimicrobial surface coating for the prevention and reduction in the spread of potentially infectious microbes.

Formation of Biofilms by Listeria monocytogenes under Various Growth Conditions

2005 ◽  
Vol 68 (1) ◽  
pp. 92-97 ◽  
Author(s):  
ANDREW G. MOLTZ ◽  
SCOTT E. MARTIN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Cell Density ◽  
Polyvinyl Chloride ◽  
Growth Medium ◽  
Biofilm Formation ◽  
Growth Conditions ◽  
Scanning Electron

Eight strains of Listeria monocytogenes (7644, 19112, 15313, Scott A, LCDC, 10403S, SLCC, and 1370) produce biofilms when grown on polyvinyl chloride microtiter well plates. The growth medium (tryptic soy broth [TSB] or modified Welshimer's broth [MWB] at 32°C) influenced the amount of biofilm formed; maximum biofilms were formed in MWB by six strains and in TSB by the remaining two strains. This result suggests that the growth medium is critical in development of L. monocytogenes biofilm. This organism also produced biofilms on stainless steel chips. Biofilm formation on these chips was observed following growth in TSB at 4, 20, and 37°C. After 20 h of incubation at 20 or 37°C, the cell density was approximately 106 CFU per chip, and after 4 days incubation at 4°C, the cell density was 105 CFU per chip. L. monocytogenes strain Scott A biofilm formation on stainless steel chips was visualized using scanning electron microscopy, which revealed dense aggregates of cells held together by meshlike webbing.

scholarly journals Impact of the contamination time by Escherichia coli on biofilm formation in surgical instruments

2021 ◽  
Vol 74 (3) ◽  
Author(s):  
Síntia de Souza Evangelista ◽  
Simone Gonçalves dos Santos ◽  
Adriana Cristina de Oliveira
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Scanning Electron Microscopy ◽  
Biofilm Formation ◽  
Surgical Instruments ◽  
Microbial Load ◽  
Surgical Instrument ◽  
E Coli ◽  
Over Time ◽  
Scanning Electron

ABSTRACT Objectives: to evaluate the microbial load and adherence of Escherichia coli in different areas of the surgical instrument surface exposed to experimental contamination over time. Methods: experimental study in which fragments of crile forceps (serrated, rod and rack) were contaminated by immersion in Tryptic Soy Broth, containing 106 CFU/mL of E. coli, for 1, 2, 4, 6, 8, 12 and 24 hours. Microbial load and bacterial adherence were evaluated using microbiological culture and scanning electron microscopy, respectively. Results: there was an increase in the microbial load on the surgical instrument, proportional to the contamination interval, ranging from 102 after 1 hour to 105 CFU/cm2 in 24 hours. The presence of exopolysaccharide was detected after two hours of contamination. Conclusions: microbial load and adhesion of E. coli increased over time, reaching 105 CFU/cm2 after 24 hours of contamination, starting biofilm formation after two hours.

scholarly journals Scanning electron microscopy of biofilm formation by Staphylococcus aureus on stainless steel and polypropylene surfaces

2014 ◽  
Vol 8 (34) ◽  
pp. 3136-3143
Author(s):  
Alessandra P. Sant’Anna Salimena ◽  
◽  
Alexandre C. Santos ◽  
Maria das Graças Cardoso ◽  
Eduardo Alves ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Stainless Steel ◽  
Biofilm Formation ◽  
Scanning Electron

Corrosion Protection of Stainless Steel by ZrO2-CeO2 Sol-Gel Coatings

2008 ◽  
Vol 368-372 ◽  
pp. 1838-1840
Author(s):  
Jian Xiong Ye ◽  
Xin Gang Yu ◽  
Wen Yue Bi ◽  
De Jun Li ◽  
Hong Wen Ma ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Stainless Steel ◽  
316L Stainless Steel ◽  
Sol Gel ◽  
Potentiodynamic Polarization Curve ◽  
Coated Substrate ◽  
Sol Gel Process ◽  
Steel Substrates ◽  
Scanning Electron

ZrO2-CeO2 thin film was successfully prepared on 316L stainless steel by sol-gel process and the corrosion characteristics of the substrate coated with ZrO2-CeO2 thin film were evaluated through potentiodynamic polarization curve obtained in deaerated 15% H2SO4. The results show that, with the increase of CeO2 content, the corrosion rate of 316L stainless steel substrates coated with ZrO2-CeO2 thin film decreases. The surface morphology of the coating was observed by field scanning electron microscopy and the elements in the surface of coated substrate analyzed by FEM-EDX.

Electrostatic Adhesion Testing for the Evaluation of Metallization Adhesion

1997 ◽  
Vol 473 ◽  
Author(s):  
H. S. Yang ◽  
F. R. Brotzen ◽  
D. L. Callahan ◽  
C. F. Dunn
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Distribution Function ◽  
Quantitative Measurement ◽  
Multilayer Films ◽  
Adhesion Testing ◽  
Novel Technique ◽  
Electrostatic Adhesion ◽  
Scanning Electron

ABSTRACTQuantitative measurement of the adhesion strength of thin film metallizations has been achieved by a novel technique employing electrostatic forces to generate delaminating stresses. This technique has been used in testing the adhesion of Al-Cu, Cu, and Al multilayer films deposited on Si. Micro-blister-type failure is revealed by scanning electron microscopy. The delamination process and the geometry of the blister are discussed. The measured adhesion data fit a Weibull distribution function.

Biological Evaluation of Selected 1,2,3-triazole Derivatives as Antibacterial and Antibiofilm Agents

2020 ◽  
Vol 20 (24) ◽  
pp. 2186-2191
Author(s):  
Lialyz Soares Pereira André ◽  
Renata Freire Alves Pereira ◽  
Felipe Ramos Pinheiro ◽  
Aislan Cristina Rheder Fagundes Pascoal ◽  
Vitor Francisco Ferreira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Public Health Problem ◽  
Biological Evaluation ◽  
Major Public Health Problem ◽  
Community Environments ◽  
Scanning Electron

Background: Resistance to antimicrobial agents is a major public health problem, being Staphylococcus aureus prevalent in infections in hospital and community environments and, admittedly, related to biofilm formation in biotic and abiotic surfaces. Biofilms form a complex and structured community of microorganisms surrounded by an extracellular matrix adhering to each other and to a surface that gives them even more protection from and resistance against the action of antimicrobial agents, as well as against host defenses. Methods: Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05). Results: Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound. Conclusion: Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.

Effects of Beef Juice on Biofilm Formation by Shiga Toxin–Producing Escherichia coli on Stainless Steel

2020 ◽  
Vol 17 (4) ◽  
pp. 235-242 ◽  
Author(s):  
Zhi Ma ◽  
Kim Stanford ◽  
Xiao M. Bie ◽  
Yan D. Niu ◽  
Tim A. McAllister
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Shiga Toxin ◽  
Biofilm Formation

scholarly journals Apolar Bioactive Fraction ofMelipona scutellarisGeopropolis onStreptococcus mutansBiofilm

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marcos Guilherme da Cunha ◽  
Marcelo Franchin ◽  
Lívia Câmara de Carvalho Galvão ◽  
Bruno Bueno-Silva ◽  
Masaharu Ikegaki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Biofilm Formation ◽  
Microbial Population ◽  
Ethanolic Extract ◽  
Vehicle Control ◽  
Sem Images ◽  
Killing Assay ◽  
Bioactive Fraction ◽  
Biofilm Matrix ◽  
Scanning Electron

The aim of this study was to evaluate the influence of the bioactive nonpolar fraction of geopropolis onStreptococcus mutansbiofilm. The ethanolic extract ofMelipona scutellarisgeopropolis was subjected to a liquid-liquid partition, thus obtaining the bioactive hexane fraction (HF) possessing antimicrobial activity. The effects of HF onS. mutansUA159 biofilms generated on saliva-coated hydroxyapatite discs were analyzed by inhibition of formation, killing assay, and glycolytic pH-drop assays. Furthermore, biofilms treated with vehicle control and HF were analyzed by scanning electron microscopy (SEM). HF at 250 μg/mL and 400 μg/mL caused 38% and 53% reduction in the biomass of biofilm, respectively, when compared to vehicle control (P<0.05) subsequently observed at SEM images, and this reduction was noticed in the amounts of extracellular alkali-soluble glucans, intracellular iodophilic polysaccharides, and proteins. In addition, theS. mutansviability (killing assay) and acid production by glycolytic pH drop were not affected (P>0.05). In conclusion, the bioactive HF of geopropolis was promising to control theS. mutansbiofilm formation, without affecting the microbial population but interfering with its structure by reducing the biochemical content of biofilm matrix.

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