Detonation nanodiamonds as enhancers of E. coli photodynamic inactivation by phthalocyanines in a high molarity buffer solution

2022 ◽  
pp. 112387
Author(s):  
D.A. Gvozdev ◽  
V.R. Gudkova ◽  
A.M. Moisenovich ◽  
А.А. Ramonova ◽  
M.G. Strakhovskaya ◽  
...  
Keyword(s):  
Detonation Nanodiamonds ◽  
Photodynamic Inactivation ◽  
Buffer Solution ◽  
E Coli

Reduction of Escherichia coli O157:H7 Counts on Whole Fresh Apples by Treatment with Sanitizers

2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER
Keyword(s):  
Escherichia Coli ◽  
Chlorine Dioxide ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Escherichia Coli O157 ◽  
Peroxyacetic Acid ◽  
Water Control ◽  
Buffer Solution ◽  
E Coli ◽  
Log Reduction

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.

scholarly journals Microfluidic Platform combined with a Dark Field Imaging System for Quantification of E. coli Contamination in Water

2021 ◽  
Author(s):  
Anna Malec ◽  
Christoph Haiden ◽  
Georgios Kokkinis ◽  
Ioanna Giouroudi
Keyword(s):  
Magnetic Particles ◽  
Imaging System ◽  
Optical Resolution ◽  
Dark Field ◽  
Small Sample ◽  
Resolution Limit ◽  
Buffer Solution ◽  
E Coli ◽  
Dark Field Imaging ◽  
Field Imaging

In this paper, we present a method for detecting and quantifying pathogens in water samples. The method proposes a portable dark field imaging and analysis system for quantifying E. coli concentrations in water after being labeled with magnetic particles. The system utilizes the tracking of moving micro/nano objects close to or below the optical resolution limit confined in small sample volumes (~ 10 µl). In particular, the system analyzes the effect of volumetric changes due to bacteria conjugation to magnetic microparticles (MP) on their Brownian motion while being suspended in liquid buffer solution. The method allows for a simple inexpensive implementation and the possibility to be used as point-of-need testing system. Indeed, a work-ing prototype is demonstrated with the capacity of quantifying E. coli colony forming units (CFU) at a range of 1x10³ - 6x10³ CFU/mL.

SIMULTANEOUS CONCENTRATION AND DETECTION OF ESCHERICHIA COLI USING CARBON NANOTUBE DEVICES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350056 ◽  
Author(s):  
DONG-WON PARK ◽  
WON-JIN CHOI ◽  
CHEOL SOO YANG ◽  
SERIN PARK ◽  
EUN MI SEO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Carbon Nanotube ◽  
Chemical Vapor ◽  
Sensor Surface ◽  
Buffer Solution ◽  
E Coli ◽  
Carbon Nanotube Network ◽  
Carbon Nanotube Devices ◽  
Time Required ◽  
Network Device

The performance of a nanoscale sensor is not limited by the sensitivity of the sensor itself but rather by the diffusion time required for target molecules to reach to the extremely small sensor surface. In this work, we developed a carbon nanotube device that performed the dual functions of concentrating and detecting microorganisms in a sample solution. The sensor surface area was increased by fabricating a carbon nanotube network device using thermal chemical vapor deposition and standard microfabrication techniques. The target Escherichia coli (E. coli) cells were concentrated at the sensor surface via dielectrophoretic concentration by the carbon nanotube network channels. After 10 min of collection, the chip was washed with ample amounts of a clean buffer solution, and only the E. coli cells that were bound to the antibodies remained on the sensor surface. The binding of E. coli to the CNT network device decreased the conductance, presumably due to an increase in the scattering at the sensor surface. The detection limit and the time required for microorganism detection was greatly improved by combining dielectrophoresis with the carbon nanotube devices.

Highly effective photodynamic inactivation of E. coli using gold nanorods/SiO2 core–shell nanostructures with embedded verteporfin

2015 ◽  
Vol 51 (91) ◽  
pp. 16365-16368 ◽  
Author(s):  
Kostiantyn Turcheniuk ◽  
Volodymyr Turcheniuk ◽  
Charles-Henri Hage ◽  
Tetiana Dumych ◽  
Rostyslav Bilyy ◽  
...  
Keyword(s):  
Urinary Tract Infection ◽  
Photodynamic Therapy ◽  
Gold Nanorods ◽  
Virulent Strain ◽  
Silica Shell ◽  
Core Shell ◽  
Photodynamic Inactivation ◽  
E Coli ◽  
Shell Nanostructures ◽  
20 Nm

The potential of gold nanorods coated with a 20 nm silica shell loaded with verteporfin as efficient NIR nanostructures for photodynamic therapy to eradicate a virulent strain of E. coli associated with urinary tract infection is described.

scholarly journals Improving vaccine efficacy based on non-covalent photoinactivation of microorganisms - sources vaccine antigens (MSVA)

2020 ◽  
Author(s):  
Artur Martynov ◽  
Boris Farber ◽  
Tatyana Osolodchenko ◽  
Ilya Klein
Keyword(s):  
Protective Effect ◽  
Blue Light ◽  
Bacterial Growth ◽  
Final Concentration ◽  
Control Group ◽  
Photodynamic Inactivation ◽  
E Coli ◽  
Light Emitter ◽  
Vaccine Antigens ◽  
Inactivated Vaccines

AbstractOne of the most promising methods for non-covalent inactivation of vaccine-producing microorganisms is the use of photoinactivation using riboflavin derivatives. The study used a dynamic combinatorial derivative of riboflavin - succinyl-maleinyl riboflavin. Corpuscular vaccines are divided into the following groups: from 2AB to 5AB - bacteria were inactivated by riboflavin derivative and blue light, and groups from 6AB to 9AB were inactivated by formalin (0.1% formalin in 9 log CFU was kept for 2 weeks in an thermostat and then sterility was determined - bacterial growth was not observed). A dynamic derivative of riboflavin at a final concentration of 0.02% can photo inactivate 6 time more bacteria P. Aeruginosa and E. coli than riboflavin. The minimum effective blue light emitter power (450 nm) for the photodynamic inactivation of both P. aeruginosa and E. coli is 1024.2 mW / cm2. In groups of mice pre-vaccinated intraperitoneally with corpuscular photo inactivated vaccines based on suspensions of and E. coli at doses of 0.5-1.0 ml 4 log (CFU) / mL, 100% survival of all animals was observed, whereas in control group with the same type of vaccines but formalin-treated vaccines, it failed to achieve a 100% protective effect.

scholarly journals Photodynamic Inactivation of Bacteria with Porphyrin Derivatives: Effect of Charge, Lipophilicity, ROS Generation, and Cellular Uptake on Their Biological Activity In Vitro

2020 ◽  
Vol 21 (22) ◽  
pp. 8716
Author(s):  
Adam Sułek ◽  
Barbara Pucelik ◽  
Marcin Kobielusz ◽  
Agata Barzowska ◽  
Janusz M. Dąbrowski
Keyword(s):  
Cellular Uptake ◽  
Efflux Pump ◽  
Theoretical Calculations ◽  
Resistant Bacteria ◽  
Ros Generation ◽  
Photodynamic Inactivation ◽  
Efflux Pump Inhibitor ◽  
E Coli ◽  
Charge Interaction

Resistance of microorganisms to antibiotics has led to research on various therapeutic strategies with different mechanisms of action, including photodynamic inactivation (PDI). In this work, we evaluated a cationic, neutral, and anionic meso-tetraphenylporphyrin derivative’s ability to inactivate the Gram-negative and Gram-positive bacteria in a planktonic suspension under blue light irradiation. The spectroscopic, physicochemical, redox properties, as well as reactive oxygen species (ROS) generation capacity by a set of photosensitizers varying in lipophilicity were investigated. The theoretical calculations were performed to explain the distribution of the molecular charges in the evaluated compounds. Moreover, logP partition coefficients, cellular uptake, and phototoxicity of the photosensitizers towards bacteria were determined. The role of a specific microbial efflux pump inhibitor, verapamil hydrochloride, in PDI was also studied. The results showed that E. coli exhibited higher resistance to PDI than S. aureus (3–5 logs) with low light doses (1–10 J/cm2). In turn, the prolongation of irradiation (up to 100 J/cm2) remarkably improved the inactivation of pathogens (up to 7 logs) and revealed the importance of photosensitizer photostability. The PDI potentiation occurs after the addition of KI (more than 3 logs extra killing). Verapamil increased the uptake of photosensitizers (especially in E. coli) due to efflux pump inhibition. This effect suggests that PDI is mediated by ROS, the electrostatic charge interaction, and the efflux of photosensitizers (PSs) regulated by multidrug-resistance (MDR) systems. Thus, MDR inhibition combined with PDI gives opportunities to treat more resistant bacteria.

PROTOTYPE UNITS TO ADDRESS EMERGING CONTAMINANTS AND E. COLI IN WASTEWATER VIA PHOTODYNAMIC INACTIVATION

2017 ◽  
Author(s):  
Matheus Pires de Mattos Fiuza ◽  
Klysman Rezende Alves Vieira ◽  
Rosana de Carvalho Cruz ◽  
Betânia Maria Soares ◽  
Meinhard Sesselmann ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Photodynamic Inactivation ◽  
E Coli

Relationship between Bdellovibrio bacteriovorus 6-5-S and autoclaved host bacteria

1972 ◽  
Vol 18 (12) ◽  
pp. 1941-1948 ◽  
Author(s):  
S. F. Crothers ◽  
H. B. Fackrell ◽  
J. C. C. Huang ◽  
J. Robinson
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Growth Rate ◽  
Reducing Sugars ◽  
Culture Fluid ◽  
Amino Sugars ◽  
Buffer Solution ◽  
Bdellovibrio Bacteriovorus ◽  
Initial Concentration ◽  
E Coli

Bdellovibrio bacteriovorus, strain 6-5-S, multiplied in the presence of washed suspensions of Escherichia coli, Spirillum serpens VHL, and Bacillus megaterium which had been autoclaved for 5 min at 121C. No intracellular life cycle was observed. Bdellovibrio bacteriovorus was also able to multiply in an extract from autoclaved E. coli cells after the cells had been removed by centrifugation. Growth of the parasite was dependent upon the addition of Ca2+ and Mg2+ to the buffer solution. The growth rate and yield of B. bacteriovorus on autoclaved cells were not affected by the initial concentration of the parasite. During multiplication of B. bacteriovorus, amino acids, amino sugars, and reducing sugars were released into the culture fluid.

Anti-Bacteria Behaviors of TaN-Cu and TaN-Ag Nanocomposite Thin Films

2010 ◽  
Vol 66 ◽  
pp. 142-149 ◽  
Author(s):  
Jang Hsing Hsieh ◽  
T.H. Yeh ◽  
C.S. Chiou ◽  
C.T. Huang ◽  
C. Li
Keyword(s):  
Film Surface ◽  
Nanocomposite Films ◽  
Metal Particles ◽  
Buffer Solution ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Ion Concentrations ◽  
Gram Positive Bacteria ◽  
Nanocomposite Thin Films

TaN–Cu and TaN-Ag nanocomposite films were deposited by reactive co-sputtering on Si. The films were then annealed using RTA (Rapid Thermal Annealing) at 400 °C for 2, 4, 8, 15 minutes respectively to induce the nucleation and growth of metal particles in TaN matrix and on film surface. The samples were then tested for their anti-bacterial behaviors against Gram-negative and Gram-positive bacteria. The results were compared with the solubility of Ag and Cu in a buffer solution. Under similar ion concentrations, it is concluded that Ag ion or TaN-Ag is more effective against E. Coli (Gram-negative), while Cu ion or TaN-Cu is more effective against Staphylococcus aureus (Gram-positive).

scholarly journals Antibiotic resistance profile of commensal Escherichia coli isolated from healthy sheep in Qatar

2020 ◽  
Vol 14 (02) ◽  
pp. 138-145
Author(s):  
Nahla Eltai ◽  
Asmaa A Al Thani ◽  
Sara H Al-Hadidi ◽  
Elmoubasher A Abdfarag ◽  
Hamad Al-Romaihi ◽  
...  
Keyword(s):  
Phosphate Buffer Solution ◽  
Antibiotic Use ◽  
Test Method ◽  
Resistant Bacteria ◽  
Buffer Solution ◽  
E Coli ◽  
Antibiotic Resistance Profile ◽  
Stewardship Program ◽  
Antibiotics Use ◽  
Food Animals

Introduction: The uncontrolled antibiotics use in livestock is a leading factor for the emergence and spread of resistant bacteria from food animals to humans through the food chain. This study aims at evaluating the magnitude of the antimicrobial resistance (AMR) in food animals, acknowledging the lack of information on the prevalence of resistance in the veterinary field in Qatar. Methodology: Rectal samples were collected from 171 sheep across three localities in Qatar between December 2016 and July 2017. These rectal samples were suspended in Phosphate buffer solution (PBS). Then streaked onto a selective CHROMagar E. coli medium plates and incubated at 37°C for 18 to 24 h. Isolated E. coli were tested for antibiotic susceptibility against 16 clinically- relevant antibiotics using the E-test method. Statistical analyses were performed using SPSS statistics 24. Results: E. coli was isolated from 144 samples (84.2%), of which 90% were resistant to at least one antibiotic and 44% were multi-drug resistant (MDR). The highest resistance was against ciprofloxacin 69.4% (100), followed by nitrofurantoin 47.2% (68), trimethoprim/sulfamethoxazole 45.8% (66), cephalothin 43% (62) and amoxicillin/clavulanic acid 18% (26). Low resistance was reported to fosfomycin, amikacin and tigecycline 1.4% (2), 0.7% (1), and 0.7% (1), respectively. Conclusions: We reported high MDR E. coli in rectal swabs of sheep in Qatar. Such resistant bacteria can potentially be transmitted to humans, resulting in public health concerns. This requires a quick response to develop and implement a stewardship program for the monitoring of antibiotic use in the veterinary in Qatar.

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