Novel Alkali-Activated Materials with Photocatalytic and Bactericidal Properties Based on Ceramic Tile Waste

Ceramics tile wastes (CWs) were mechanically conditioned for the preparation of alkali-activated hybrid-cements from CW (90 wt.%) and Portland cement (10 wt.%) mixtures using sodium silicate (SS) + NaOH as alkaline activators. Molar ratios of SiO2/Al2O3 (6.3 to 7.7) and Na2O/SiO2 (0.07 to 0.16) were used. The cements were prepared at room temperature (25 °C) and characterized by mechanical and physical properties and microstructure. The optimized cement was used for the preparation of novel photoactivated composite materials by incorporating 5 and 10 wt.% TiO2 (Ti) and ZnO (Z) nanoparticles, and its self-cleaning and bactericidal properties were evaluated by means of the degradation of rhodamine-B (Rh-B) and the growth inhibition of Klebsiella pneumoniae and Pseudomonas aeruginosa bacteria. The results of this study showed that the 100SS-5Z and 50SS:50G-10Ti cements have an effective photocatalytic activity for Rh-B degradation of 98.4% and 76.4%, respectively, after 24 h. Additionally, the 100SS-5Z and 50SS:50G-10Ti cement pastes and their respective mortars were effective in inhibiting the growth of Pseudomonas Aeruginosa and Klebsiella pneumoniae bacterial strains, evidenced by the formation of bacterial inhibition halos around the sample discs. Finally, these results are novel, and open the possibility of using constructions and demolition tile waste in high proportions for the elaboration of new rendering mortar with innovative properties.

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Novel Pt-Ag3PO4/CdS/Chitosan Nanocomposite with Enhanced Photocatalytic and Biological Activities

Nanomaterials ◽

10.3390/nano10112320 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2320

Author(s):

Mahsa Kiani ◽

Mojtaba Bagherzadeh ◽

Reyhaneh Kaveh ◽

Navid Rabiee ◽

Yousef Fatahi ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Pseudomonas Aeruginosa ◽

Antibacterial Activity ◽

Photocatalytic Activity ◽

Klebsiella Pneumoniae ◽

Visible Light ◽

Salmonella Typhimurium ◽

Bacillus Cereus ◽

Visible Light Irradiation ◽

Light Irradiation

Decorating photocatalysts with noble metal nanoparticles (e.g., Pt) often increases the catalysts’ photocatalytic activity and biomedical properties. Here, a simple and inexpensive method has been developed to prepare a Pt-Ag3PO4/CdS/chitosan composite, which was characterized and used for the visible light-induced photocatalytic and antibacterial studies. This synthesized composite showed superior photocatalytic activity for methylene blue degradation as a hazardous pollutant (the maximum dye degradation was observed in 90 min of treatment) and killing of Gram positive bacterial (Staphylococcus aureus and Bacillus cereus) as well as Gram negative bacteria (Klebsiella pneumoniae, Salmonella typhimurium, Escherichia coli, and Pseudomonas aeruginosa) under visible light irradiation. The antibacterial activity of CdS, CdS/Ag3PO4, and Pt-Ag3PO4/CdS/chitosan against E. coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella pneumoniae, Staphylococcus aureus, and Bacillus cereus showed the zone of inhibition (mm) under visible light and under dark conditions at a concentration of 20 µg mL−1. Furthermore, the cell viability of the CdS/chitosan, Ag3PO4, Ag3PO4/CdS/chitosan, and Pt-Ag3PO4/CdS/chitosan were investigated on the human embryonic kidney 293 cells (HEK-293), Henrietta Lacks (HeLa), human liver cancer cell line (HepG2), and pheochromocytoma (PC12) cell lines. In addition, the results indicated that the photodegradation rate for Pt-Ag3PO4/CdS/chitosan is 3.53 times higher than that of CdS and 1.73 times higher than that of the CdS/Ag3PO4 composite. Moreover, Pt-Ag3PO4/CdS/chitosan with an optimal amount of CdS killed large areas of different bacteria and different cells separately in a shorter time period under visible-light irradiation, which shows significantly higher efficiency than pure CdS and other CdS/Ag3PO4 composites. The superb performances of this composite are attributed to its privileged properties, such as retarded recombination of photoinduced electron/hole pairs and a large specific surface area, making Pt-Ag3PO4/CdS/chitosan a valuable composite that can be deployed for a range of important applications, such as visible light-induced photocatalysis and antibacterial activity.

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Comparison of Petroleum Hydrocarbons Degradation by Klebsiella pneumoniae and Pseudomonas aeruginosa

Applied Sciences ◽

10.3390/app8122551 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2551 ◽

Cited By ~ 3

Author(s):

Zhaoyang You ◽

Haiyang Xu ◽

Shujuan Zhang ◽

Hyunook Kim ◽

Pen-Chi Chiang ◽

...

Keyword(s):

Surface Tension ◽

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Petroleum Hydrocarbons ◽

Abiotic Factors ◽

Lower Surface ◽

Temporal Variations ◽

Bacterial Strains ◽

Relative Growth ◽

Diesel Degradation

: The aim of this work was to develop bacterial communities to effectively degrade petroleum hydrocarbons (PHs). We investigated the biotic and abiotic contributors to differences in PHs degradation efficacy between two bacterial strains, Klebsiella pneumoniae (Kp) and Pseudomonas aeruginosa (Pa), screened out from the activated sludge of a petroleum refinery. We characterized the temporal variations in degradation efficacy for diesel and its five major constituents as a sole carbon source and identified more constituents they degraded. The growth characteristics, surface tension, hydrophobicity and emulsifiability of these two strains were measured. We further estimated the relationships between their degradation efficacy and all the biotic and abiotic factors. Results showed that the Pa strain had higher diesel degradation efficacy (58% on Day 14) and utilized more diesel constituents (86%) compared to Kp. Additionally, the growth of the Pa strain in diesel medium was faster than that of the Kp strain. The Pa strain had a lower surface tension and higher hydrophobicity and emulsifiability than Kp, while the surfactant produced by Pa was identified as rhamnolipids. Degradation of PHs was positively related to bacterial growth, hydrophobicity and emulsification but negatively related to surface tension. Overall, differences in degrading capacity for diesel constituents, relative growth rate, and biosurfactant production contributed to the variation in the PHs degradation efficacy of these two bacterial strains.

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Deformation of Alkali-Activated Materials at an Early Age Under Different Curing Conditions

Frontiers in Chemistry ◽

10.3389/fchem.2021.694454 ◽

2021 ◽

Vol 9 ◽

Author(s):

Mark Češnovar ◽

Katja Traven ◽

Vilma Ducman

Keyword(s):

Relative Humidity ◽

Room Temperature ◽

Standard Procedure ◽

Autogenous Shrinkage ◽

Drying Shrinkage ◽

Mineral Wool ◽

Cement Pastes ◽

Curing Conditions ◽

Material Sources ◽

Alkali Activated

The production of alkali-activated materials (AAMs) is known for its environmentally friendly processing method, where several amorphous-rich aluminosilicate material sources combine with an alkali media solution to form solid, ceramic-like materials. In terms of the Si:Al, Na(K):Al, and Na(K):H2O ratios, the theory of AAM formation is quite well developed, but some open questions in the technology process remain, especially with regards to the means of curing, where the generation of defects can be persistent. Knowing that deformation is extremely high in the early ages, this study investigates the effects of temperature and moisture on shrinkage behavior within the first 72 h of AA pastes made from ladle (LS) and electric arc furnace (EAF) slag and activated by sodium silicate (Na2SiO3). The method to determine the deformation of alkali-activated slag-based materials, in terms of both autogenous and drying shrinkage, was based on the modified ASTM C1698-19 standard for the measurement of autogenous shrinkage in cement pastes. Autogenous deformation and strain were measured in four samples, using the standard procedure at room temperature, 40 and 60°C. Furthermore, using an adjusted method, nine samples were characterized for strain and partial surface pressure, while drying at room temperature, 40, or 60°C at a relative humidity of 30 or 90%. The results show that the highest rate of autogenous shrinkage occurred at a temperature of 60°C, followed by drying shrinkage at 60°C and 30% relative humidity, owing to the fact that the rate of evaporation was highest at this moisture content. The study aimed to provide guidance regarding selection of the optimal curing set in order to minimize deformations in slag-based alkali-activated materials. In the present case, curing at a temperature of around 40°C under lower moisture conditions for the first 24 h provided optimal mechanical properties for the slags investigated. The methodology might also be of use for other aluminosilicate sources such as metakaolin, fly ash, and mineral wool–based alkali-activated materials.

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The Analysis Of Antibiotic Consumption And Bacterial Resistance As An Indicator Of Their Proper Use At The Urology Department In The Health Centre “Studenica” Kraljevo

Serbian Journal of Experimental and Clinical Research ◽

10.1515/sjecr-2015-0018 ◽

2015 ◽

Vol 16 (2) ◽

pp. 135-141

Author(s):

Andriana Bukonjić ◽

Srđan Stefanović

Keyword(s):

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Bacterial Resistance ◽

Health Centre ◽

Antibiotic Consumption ◽

Resistance Rate ◽

Gram Negative Bacteria ◽

Financial Assets ◽

Bacterial Strains ◽

Gram Negative

Abstract The objective of the study was to analyze antibiotic consumption and determine bacterial resistance rates as an indicator of the rational utilization of this drug group at the urology department in the Health Centre “Studenica” Kraljevo. Over a two-year period, the average antibiotic consumption was 104.55 DDD/100BD. Of the total financial assets used for medical treatment, the antibiotic group JO1 had a share of 49.52% in 2011 and 47.53% in 2012. Antibacterial drugs from a group of β-lactamic antibiotics were consumed most commonly, at 54.02% (2011) and 43.44% (2012). First-generation cephalosporins, quinolones and aminoglycosides were the most frequently used drug groups, while cephalexin was the antibiotic with the highest individual consumption. E. coli was the most frequently isolated bacterium in 2011, while in 2012, Klebsiella pneumoniae was the most frequently isolated bacterium. The total bacterial resistance both in 2011 and 2012 was above 50%. Gram-negative bacteria showed a higher resistance rate (2011, 59.3%; 2012, 58.9%) than Gram-positive bacteria (2011, 44.4%; 2012, 40.6%). Klebsiella pneumoniae was the bacterium with the highest resistance (75.3%) in 2011, while in 2012, there was a resistance increase in Pseudomonas aeruginosa (71.4%), especially to carbapenems. A correlation was determined between the consumption of individual antibiotics and bacterial strain resistance in 2011 (r=0.433, p=0.044) and in 2012 (r=0.478, p=0.024). The high resistance rate shown in the bacterial strains, which was correlated with antibiotic consumption, as well as the great financial assets used for this group of drugs suggest the necessity for the rationalization of their utilization. Empirical therapy with Gram-negative bacteria should be based on carbapenems utilization, except with Pseudomonas aeruginosa, where piperacillin/tazobactam should be used.

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Study on antibacterial activities of Hibiscus rosa-sinensis L. Leaf and flower extracts against Proteus mirabilis, Pseudomonas aeruginosa, and Klebsiella pneumoniae

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v2i1.669 ◽

2019 ◽

Vol 2 (1) ◽

pp. 19-26

Author(s):

Luong Thi My Ngan ◽

Le Thi Kim Lan ◽

Nguyen Thi Thuy Linh ◽

Nguyen Ngoc Quy ◽

Le Thi Thanh Loan ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Proteus Mirabilis ◽

Higher Plants ◽

Ethyl Acetate Fraction ◽

Antibacterial Activities ◽

Resistant Bacteria ◽

Multiple Drug ◽

Bacterial Strains ◽

Tract Infections

Antibiotic resistance of bacterial strains causing serious diseases is one of the major concerns of public health worldwide. Metabolites of plants, particularly higher plants, have been suggested as alternative potential sources for antibacterial products due to their safe. They have little or no side effects and may act at multiple and novel target sites to bacteria. The study aims to evaluate antibacterial activities of leaf and flower extracts and solvent soluble fractions of the extracts against Proteus mirabilis, Pseudomonas aeruginosa, and Klebsiella pneumoniae, the major causes of infection-related kidney stones (struvite stones). Diameters of inhibitory zones, and MIC and MBC values of the extracts and fractions against the bacteria were evaluated. The results showed that the extracts and fractions derived from flowers have activities stronger than those from leaves, especially the ethyl acetate fraction (EtOAc fr.). The inhibitory zone diameters of 10 mg per paper disc of the EtOAC fr. towards Ps. aeruginosa, Pr. mirabilis, and K. pneumoniae were 17, 15 and 13 mm, respectively. The EtOAC fraction. had antibacterial activity against both Ps. aeruginosa and Pr. mirabilis with MIC (MBC) values of 2.5–5.0 (7.5) mg/mL and against K. pneumoniae with MIC (MBC) values of 7.5 (10) mg/mL. The fraction needs to be more studied for identifying its major active constituents. These leaf and flower extracts of H. rosa-sinensis could be used to treat against urinary tract infections caused by multiple drug resistant bacteria.

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Phage Therapy Experience at the Eliava Phage Therapy Center: Three Cases of Bacterial Persistence

Viruses ◽

10.3390/v13101901 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1901

Author(s):

Elisabed Zaldastanishvili ◽

Lika Leshkasheli ◽

Mariam Dadiani ◽

Lia Nadareishvili ◽

Lia Askilashvili ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Tract Infection ◽

Klebsiella Pneumoniae ◽

Phage Therapy ◽

Adaptation Strategy ◽

Bacterial Strains ◽

Patient Case ◽

Before And After ◽

Therapy Center ◽

Pfge Profiles

In this retrospective descriptive study we focus on cases of three patients who underwent phage therapy procedures at Eliava Phage Therapy Center (EPTC) in Tbilisi, Georgia. Patients with chronic infectious diseases related to Pseudomonas aeruginosa (two patients, lower respiratory tract infection (LRTI)) and Klebsiella pneumoniae (one patient, urinary tract infection (UTI)) are among those very few EPTC patients whose pathogens persisted through phage therapy. By looking at bacterial strains and personalized phages used against them we tried to point towards possible adaptation strategies that are employed by these pathogens. Genome restriction-based Pulsed Field Gel Electrophoresis (PFGE) profiling of strains isolated before and after phage therapy hints towards two strategies of adaptation. In one patient case (Pseudomonas aeruginosa related lung infection) bacterial strains before and after phage therapy were indistinguishable according to their PFGE profiles, but differed in their phage susceptibility properties. On the other hand, in two other patient cases (Pseudomonas aeruginosa related LRTI and Klebsiella pneumoniae related UTI) bacterial adaptation strategy seemed to have resulted in diversification of infecting strains of the same species. With this work we want to attract more attention to phage resistance in general as well as to its role in phage therapy.

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Green synthesis of mixed metallic nanoparticles using room temperature self-assembly

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v13i2.5942 ◽

2017 ◽

Vol 13 (2) ◽

pp. 4671-4677 ◽

Cited By ~ 2

Author(s):

A. M. Abdelghany ◽

A.H. Oraby ◽

Awatif A Hindi ◽

Doaa M El-Nagar ◽

Fathia S Alhakami

Keyword(s):

Self Assembly ◽

Metallic Nanoparticles ◽

Room Temperature ◽

Bimetallic Nanoparticles ◽

Reduction Process ◽

Nano Particles ◽

Nano Structure ◽

Small Shift ◽

Molar Ratios ◽

Vis Spectroscopy

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.

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Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

International Journal of Antibiotics and Probiotics ◽

10.31405/ijap.1-2.17.03 ◽

2017 ◽

Vol 1 (2) ◽

pp. 48-60

Author(s):

A.G. Salmanov ◽

A.V. Rudenko

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Staphylococcus Epidermidis ◽

Klebsiella Oxytoca ◽

Enterobacter Aerogenes ◽

Enterobacter Cloacae ◽

Proteus Vulgaris ◽

Providencia Rettgeri ◽

E Coli

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

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Activité antibactérienne de l’huile essentielle de Pelargonium x asperum et son potentiel synergique avec la nisine

Phytothérapie ◽

10.3166/phyto-2019-0183 ◽

2019 ◽

Vol 17 (3) ◽

pp. 140-148 ◽

Cited By ~ 1

Author(s):

A. Ouelhadj ◽

L. Ait Salem ◽

D. Djenane

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Nous Avons ◽

Activité Antibactérienne

Ce travail vise l’étude de l’activité antibactérienne de l’huile essentielle (HE) de Pelargoniumx asperum et de la bactériocine, la nisine seul et en combinaison vis-à-vis de six bactéries dont quatre sont multirésistantes d’origine clinique. L’activité antibactérienne in vitro a été évaluée par la méthode de diffusion sur gélose. La concentration minimale inhibitrice (CMI) est aussi déterminée pour HE. Les résultats ont révélé une activité antibactérienne significative exercée par HE visà-vis de Staphylococcus aureus (ATCC 43300), Staphylococcus aureus et Escherichia coli avec des diamètres d’inhibition de 36,00 ; 22,50 et 40,00 mm, respectivement. Cependant, l’HE de Pelargonium asperum a montré une activité antibactérienne supérieure par rapport à la nisine. Les valeurs des CMI rapportées dans cette étude sont comprises entre 1,98–3,96 μl/ml. Les combinaisons réalisées entre HE et la nisine ont montré un effet additif vis-à-vis de Escherichia coli (ATCC 25922) avec (50 % HE Pelargonium asperum + 50 % nisine). Par contre, nous avons enregistré une synergie vis-à-vis de Klebsiella pneumoniae avec (75 % HE Pelargonium asperum + 25 % nisine) et contre Pseudomonas aeruginosa avec les trois combinaisons testées. Les résultats obtenus permettent de dire que l’HE de Pelargonium asperum possède une activité antibactérienne ainsi que sa combinaison avec la nisine pourrait représenter une bonne alternative pour la lutte contre l’antibiorésistance.

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Green Solvents as an Alternative to DMF in ZIF-90 Synthesis

Molecules ◽

10.3390/molecules26061573 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1573

Author(s):

Aljaž Škrjanc ◽

Ciara Byrne ◽

Nataša Zabukovec Logar

Keyword(s):

Room Temperature ◽

Product Yield ◽

Solvent Exchange ◽

Green Solvents ◽

Zeolitic Imidazolate Framework ◽

Short Treatment ◽

Molar Ratios ◽

Primary Particles ◽

High Product Yield

The use of green solvents as an alternative to dimethylformamide (DMF) in the synthesis of zeolitic imidazolate framework-90 (ZIF-90) was investigated. Two biobased aprotic dipolar solvents CyreneTM and γ-valerolactone (GVL) proved to successfully replace DMF in the synthesis at room temperature with a high product yield. While the CyreneTM—based product shows reduced porosity after activation, the use of GVL resulted in materials with preserved crystallinity and porosity after activation, without prior solvent exchange and a short treatment at 200 °C. The primary particles of 30 nm to 60 nm in all products further form agglomerates of different size and interparticle mesoporosity, depending on the type and molar ratios of solvents used.

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