Preventing maritime transport of pathogens: the remarkable antimicrobial properties of silver-supported catalysts for ship ballast water disinfection

Ship ballast water (SBW) antimicrobial treatment is considered as a priority issue for the shipping industry. The present work investigates the possibility of utilizing antimicrobial catalysis as an effective method for the treatment of SBW. Taking into account the well-known antimicrobial properties of ionic silver (Ag+), five silver-supported catalysts (Ag/γ-Al2O3) with various loadings (0.05, 0.1, 0.2, 0.5, and 1 wt%) were prepared and examined for the antimicrobial treatment of SBW. The bactericidal activity of the aforementioned catalysts was investigated towards the inhibition of Escherichia coli (Gram-negative) and Escherichia faecalis (Gram-positive) bacteria. Catalytic experiments were conducted in a three-phase continuous flow stirred tank reactor, used in a semi-batch mode. It was found that using the catalyst with the lowest metal loading, the inhibition of E. coli reached 95.8% after 30 minutes of treatment of an E. coli bacterial solution, while the inhibition obtained for E. faecalis was 76.2% after 60 minutes of treatment of an E. faecalis bacterial solution. Even better results (100% inhibition after 5 min of reaction) were obtained using the catalysts with higher Ag loadings. The results of the present work indicate that the prepared monometallic catalysts exert their antimicrobial activity within a short period of time, revealing, for the first time ever, that the field of antimicrobial heterogeneous catalysis using deposited ionic silver on a solid support may prove decisive for the disinfection of SBW.

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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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Disinfection of Fruits with Activated Water

JOURNAL OF ADVANCES IN AGRICULTURE ◽

10.24297/jaa.v10i0.8462 ◽

2019 ◽

Vol 10 ◽

pp. 1864-1872

Author(s):

Prof. Teodora P. Popova

Keyword(s):

Antimicrobial Activity ◽

Aqueous Solutions ◽

Antimicrobial Properties ◽

The Other ◽

Gram Negative Bacteria ◽

High Antimicrobial Activity ◽

Gram Negative ◽

E Coli ◽

Number Of Microorganisms ◽

Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

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Physicochemical and Antimicrobial Properties of Cocoa Pod Husk Pectin Intended as a Versatile Pharmaceutical Excipient and Nutraceutical

Journal of Pharmaceutics ◽

10.1155/2016/7608693 ◽

2016 ◽

Vol 2016 ◽

pp. 1-12 ◽

Cited By ~ 8

Author(s):

Ofosua Adi-Dako ◽

Kwabena Ofori-Kwakye ◽

Samuel Frimpong Manso ◽

Mariam EL Boakye-Gyasi ◽

Clement Sasu ◽

...

Keyword(s):

Aqueous Media ◽

Antimicrobial Properties ◽

Microbiological Quality ◽

Elemental Content ◽

Moderate Activity ◽

Pharmaceutical Excipient ◽

E Coli ◽

Swelling Capacity ◽

Weak Activity ◽

Cocoa Pod Husk

The physicochemical and antimicrobial properties of cocoa pod husk (CPH) pectin intended as a versatile pharmaceutical excipient and nutraceutical were studied. Properties investigated include pH, moisture content, ash values, swelling index, viscosity, degree of esterification (DE), flow properties, SEM, FTIR, NMR, and elemental content. Antimicrobial screening and determination of MICs against test microorganisms were undertaken using agar diffusion and broth dilution methods, respectively. CPH pectin had a DE of 26.8% and exhibited good physicochemical properties. Pectin had good microbiological quality and exhibited pseudoplastic, shear thinning behaviour, and high swelling capacity in aqueous media. The DE, FTIR, and NMR results were similar to those of previous studies and supported highly acetylated low methoxy pectin. CPH pectin was found to be a rich source of minerals and has potential as a nutraceutical. Pectin showed dose-dependent moderate activity against gram positive and gram negative microorganisms but weak activity against Listeria spp. and A. niger. The MICs of pectin ranged from 0.5 to 4.0 mg/mL, with the highest activity against E. coli and S. aureus (MIC: 0.5–1.0 mg/mL) and the lowest activity against A. niger (MIC: 2.0–4.0 mg/mL). The study has demonstrated that CPH pectin possesses the requisite properties for use as a nutraceutical and functional pharmaceutical excipient.

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Antimicrobial Screening, in Silico Studies and QSAR of Chalcone-based 1,4-disubstituted 1,2,3-triazole Hybrids

Drug Research ◽

10.1055/a-1296-7751 ◽

2020 ◽

Author(s):

Pinki Yadav ◽

Kashmiri Lal ◽

Ashwani Kumar

Keyword(s):

Topoisomerase Ii ◽

Antimicrobial Properties ◽

Qsar Model ◽

Quantitative Structure Activity Relationship ◽

Binding Modes ◽

E Coli ◽

Structure Activity ◽

In Silico Studies ◽

Microbial Strains

AbstractThe in vitro antimicrobial properties of some chalcones (1a–1c ) and chalcone tethred 1,4-disubstituted 1,2,3-triazoles (2a–2u) towards different microbial strains viz. Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans are reported. Compounds 2g and 2u exhibited better potency than the standard Fluconazole with MIC values of 0.0063 µmol/mL and 0.0068 µmol/mL, respectively. Furthermore, molecular docking was performed to investigate the binding modes of two potent compounds 2q and 2g with E. coli topoisomerase II DNA gyrase B and C. albicans lanosterol 14α-demethylase, respectively. Based on these results, a statistically significant quantitative structure activity relationship (QSAR) model was successfully summarized for antibacterial activity against B. subtilis.

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Antimicrobial Activity of L-Lysine and Poly-L-Lysine with Pulsed Electric Fields

Applied Sciences ◽

10.3390/app11062708 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2708

Author(s):

Jurgita Švedienė ◽

Vitalij Novickij ◽

Rokas Žalnėravičius ◽

Vita Raudonienė ◽

Svetlana Markovskaja ◽

...

Keyword(s):

Electric Fields ◽

Pulsed Electric Fields ◽

Antimicrobial Treatment ◽

Treatment Development ◽

E Coli ◽

Yeast Fungi ◽

New Treatment ◽

First Time ◽

Resistant Microorganism ◽

Susceptibility Patterns

For the first time, the possibility to use L-lysine (Lys) and poly-L-lysine (PLL) as additives with pulsed electric fields (PEF) for antimicrobial treatment is reported. The antimicrobial efficacy of Lys and PLL for Escherichia coli, Staphylococcus aureus, Trichophyton rubrum and Candida albicans was determined. Inactivation of microorganisms was also studied by combining Lys and PLL with PEF of 15 and 30 kV/cm. For PEF treatment, pulses of 0.5, 1, 10 or 100 μs were applied in a sequence of 10 to 5000 at 1 kHz frequency. The obtained results showed that 100 μs pulses were the most effective in combination with Lys and PLL for all microorganisms. Equivalent energy PEF bursts with a shorter duration of the pulse were less effective independently on PEF amplitude. Additionally, various treatment susceptibility patterns of microorganisms were determined and reported. In this study, the Gram-negative E. coli was the most treatment-resistant microorganism. Nevertheless, inactivation rates exceeding 2 log viability reduction were achieved for all analyzed yeast, fungi, and bacteria. This methodology could be used for drug-resistant microorganism’s new treatment development.

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Conditions to Prolonged Release of Microencapsulated Carvacrol on Alginate Films as Affected by Emulsifier Type and PH

International Journal of Polymer Science ◽

10.1155/2015/173193 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Silvia Matiacevich ◽

Natalia Riquelme ◽

María Lidia Herrera

Keyword(s):

Storage Time ◽

Antimicrobial Agents ◽

Antimicrobial Properties ◽

Edible Film ◽

Initial Time ◽

Tween 20 ◽

Prolonged Release ◽

E Coli ◽

Fresh Foods

Alginate from algal biomass is used as edible film and the incorporation of antimicrobial agents improves its performance to increase the shelf-life of fresh foods. However, environmental conditions and intrinsic properties of films influence their release. The aim of this study was to investigate the effect of the concentration and type of encapsulating agent and pH of emulsions on the physical and antimicrobial properties of alginate-carvacrol films. Films containing alginate, carvacrol as antimicrobial agent, and Tween 20 or trehalose (0.25 and 0.75% w/w) as encapsulating agents were obtained from suspensions at pH 4 and pH 8. Physical characterization of emulsions and films and antimicrobial properties (E. coliandB. cinerea) was evaluated. Results showed that droplets size depended on trehalose concentration, but emulsion stability depended on pH and type of encapsulating agent, being more stable samples with trehalose at pH 4. Although films with Tween 20 presented the highest opacity, they showed the best antimicrobial properties at initial time; however, during storage time, they lost their activity before samples with trehalose and relative humidity (RH) was the principal factor to influence their release. Therefore, sample formulated with 0.25% trehalose at pH 4 and stored at 75% RH had the best potential as edible film for fresh fruits.

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Synthesis and Antimicrobial Properties of Highly Cross-Linked pH-Sensitive Hydrogels through Gamma Radiation

Polymers ◽

10.3390/polym13142223 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2223

Author(s):

Moises Bustamante-Torres ◽

Victor H. Pino-Ramos ◽

David Romero-Fierro ◽

Sandra P. Hidalgo-Bonilla ◽

Héctor Magaña ◽

...

Keyword(s):

Bacterial Infections ◽

Antimicrobial Agents ◽

Film Formation ◽

Antimicrobial Properties ◽

Ph Sensitive ◽

Scanning Calorimetry ◽

Polymeric Systems ◽

E Coli ◽

High Prevalence

The design of new polymeric systems for antimicrobial drug release focused on medical/surgical procedures is of great interest in the biomedical area due to the high prevalence of bacterial infections in patients with wounds or burns. For this reason, in this work, we present a new design of pH-sensitive hydrogels copolymerized by a graft polymerization method (gamma rays), intended for localized prophylactic release of ciprofloxacin and silver nanoparticles (AgNPs) for potential topical bacterial infections. The synthesized hydrogels were copolymerized from acrylic acid (AAc) and agar. Cross-linked hydrogel film formation depended on monomer concentrations and the degree of radiation used (Cobalt-60). The obtained hydrogel films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical testing. The swelling of the hydrogels was evidenced by the influence of their pH-sensitiveness. The hydrogel was loaded with antimicrobial agents (AgNPs or ciprofloxacin), and their related activity was evaluated. Finally, the antimicrobial activity of biocidal-loaded hydrogel was tested against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) on in vitro conditions.

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Two Novel Mutations Associated with Polymyxin-B Resistance in a Pandemic Lineage of Uropathogenic Escherichia coli of the Sequence Type 69

Chemotherapy ◽

10.1159/000517817 ◽

2021 ◽

pp. 1-7

Author(s):

Carla Adriana dos Santos ◽

Rodrigo Tavanelli Hernandes ◽

Marcos Paulo Vieira Cunha ◽

Filipe Onishi Nagamori ◽

Claudia Regina Gonçalves ◽

...

Keyword(s):

Escherichia Coli ◽

Susceptibility Testing ◽

Polymyxin B ◽

Antimicrobial Treatment ◽

Sequence Type ◽

Broth Microdilution ◽

Economic Costs ◽

Novel Mutations ◽

E Coli ◽

Total Inhibition

Background: Uropathogenic Escherichia coli (UPEC) are frequent pathogens worldwide, impacting on the morbidity and economic costs associated with antimicrobial treatment. Objectives: We report two novel mutations associated with polymyxin-B resistance in an UPEC isolate collected in 2019. Methods: Isolate was submitted to antimicrobial susceptibility testing including broth microdilution for polymyxin B. Whole genome was sequenced and analyzed. Results: Polymyxin-B total inhibition occurred at 16 mg/L (resistant). UPEC isolate was assigned to the phylogroup D, serotype O117:H4, and Sequence Type 69. mcr genes were not detected, but two novel mutations in the pmrA/basS (A80S) and pmrB/basR (D149N) genes were identified. Conclusions: The occurrence of non-mcr polymyxin resistance in E. coli from extraintestinal infections underscores the need of a continuous surveillance of this evolving pathogen.

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Performance of silver-coated red soil nanocomposites in water disinfection

Water Quality Research Journal ◽

10.2166/wqrj.2018.021 ◽

2018 ◽

Vol 54 (1) ◽

pp. 70-78 ◽

Cited By ~ 1

Author(s):

Ebrahim Mahmoudi ◽

Farid Moeinpour

Keyword(s):

Contact Time ◽

Elimination Rate ◽

Red Soil ◽

Water Disinfection ◽

Box Behnken Design ◽

E Coli ◽

Surface Response Method ◽

Research Findings ◽

Response Method ◽

Bacterial Effect

Abstract The present research studied the anti-bacterial effect of silver-coated red soil nanoparticles on Gram-negative bacteria Escherichia coli (E. coli) from water. The effects of disinfectant concentration (0.02, 0.05 and 0.1 g/mL), contact time (10, 20 and 30 minutes) and bacteria number (102, 104 and 106 CFU/mL) have been also investigated. To obtain important factors, the interactions between factors and optimal experimental design in surface response method were used based on Box-Behnken design. According to the research findings, the system is efficient in eliminating E. coli. The results showed that E. coli elimination efficiency intensified through increasing the amount of disinfectant from 0.02 to 0.1 g/mL. Expanding contact time from 10 minutes to 30 minutes also heightened the E. coli elimination rate. R2 for E. coli elimination is 0.9956 indicating a good agreement between model experimental data and forecasting data.

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Antimicrobial Interventions to Reduce Shiga Toxin-Producing Escherichia coli (STEC) Surrogate Populations on Beef Striploins Intended for Blade Tenderization

Meat and Muscle Biology ◽

10.22175/mmb.10704 ◽

2019 ◽

Vol 3 (2) ◽

Author(s):

C. L. Thomas ◽

H. Thippareddi ◽

M. Rigdon ◽

S. Kumar ◽

R. W. McKee ◽

...

Keyword(s):

Escherichia Coli ◽

Sodium Dodecyl ◽

Antimicrobial Treatment ◽

Sodium Chlorite ◽

Beef Industry ◽

Anterior Portion ◽

E Coli ◽

Group Data ◽

Blade Tenderization ◽

Antimicrobial Interventions

ObjectivesBlade tenderization (BT) is used in the beef industry to improve tenderness of steaks prepared from subprimals but can translocate surface pathogens to the interior of meat. Application of antimicrobial solutions on the surface of subprimals prior to blade tenderization can reduce the risk of translocation of surface microorganisms. The objectives of this research were: 1) evaluate the efficacy of antimicrobial interventions applied to inoculated (surrogate Escherichia coli) beef striploins prior to blade tenderization; and 2) examine the transfer of E. coli from inoculated striploins to subsequent non-inoculated subprimals.Materials and MethodsThe anterior portion of whole muscle beef striploins (30.48 cm) were inoculated (lean side) across a 10 cm band with an approximately 8.00 log CFU/mL cocktail containing non-pathogenic, rifampicin-resistant surrogate STEC strains (BAA-1427, BAA-1428, BAA-1429, BAA-1430, and BAA-1431). The inoculated striploins were sprayed with (1) levulinic acid (5.0%) + sodium dodecyl sulfate (0.50%) (LVA+SDS), (2) peroxyacetic acid (2000 ppm; PAA; FCN 1666), (3) acidified sodium chlorite (1200 ppm; ASC), or (4) lactic acid (4.5%; LA) by passing through a spray cabinet and blade tenderized, along with an inoculated, non-sprayed control (CON). To evaluate the potential for cross-contamination of subsequent subprimals, an inoculated striploin (for each treatment) was blade tenderized followed by a non-inoculated beef striploin. For each striploin, surface and subsurface samples (2.54 cm wide) were collected from three different locations including the anterior, middle, and posterior end of each striploin. A total of 30 striploins across three replications were randomly assigned to treatment stratification. Sponge samples were also collected from the blade tenderizer (plate of the blade unit and blades) after each treatment group. Data were analyzed using Proc Mixed (SAS Inst., v.9.4; Cary, NC) as a completely randomized split-plot design. Microbial counts for all samples were log transformed and then analyzed for the main effects of antimicrobial treatment, location (anterior to posterior and surface or interior), and their interaction. Differences were considered significant at α ≤ 0.05.ResultsPAA was more effective in reducing E. coli populations (1.80 log CFU/g; P ≤ 0.05) and had lowest recovery of the microorganism from the striploin subsurface compared to other treatments, followed by LVA+SDS (1.00 log CFU/g). E. coli populations gradually decreased (P ≤ 0.05) on the surface and subsurface as sampling moved anterior to posterior. However, E. coli populations were similar (P > 0.05) on the posterior end of inoculated striploins and the anterior end of the subsequent, non-inoculated striploins, indicating transfer of microorganisms from one striploin to the following striploin. E. coli populations of 3.03 log CFU/cm2 and 2.47 log CFU/cm2 were recovered from the plate of the blade unit and the blades of the blade tenderizer. E. coli populations recovered from the plastic plate (3.46 log CFU/cm2) and blades (2.87 log CFU/cm2) of the blade tenderizer were the similar (P > 0.05) for all treatment groups except for PAA (1.41 log CFU/cm2 and 0.97 log CFU/cm2, respectively).ConclusionThese results showed that PAA and LVA+SDS can be used to improve the safety of blade tenderized beef.

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