scholarly journals Gram-scale synthesis of splat-shaped Ag–TiO2 nanocomposites for enhanced antimicrobial properties

2020 ◽  
Vol 11 ◽  
pp. 1119-1125
Author(s):  
Mohammad Jaber ◽  
Asim Mushtaq ◽  
Kebiao Zhang ◽  
Jindan Wu ◽  
Dandan Luo ◽  
...  

The control over contagious diseases caused by pathogenic organisms has become a serious health issue. The extensive usage of antibiotics has led to the development of multidrug-resistant bacterial strains. In this regard, metal-oxide-based antibacterial nanomaterials have received potential research interest due to the efficient prevention of microorganism growth. In this study, splat-shaped Ag–TiO2 nanocomposites (NCs) were synthesized on the gram scale and the enhanced antibacterial properties of TiO2 in the presence of silver were examined. The formation of Ag–TiO2 NCs was analyzed through various characterization techniques. The cell viability experimental results demonstrated that the Ag–TiO2 NCs have good biocompatibility. The antibacterial activity of the prepared Ag–TiO2 NCs was tested against the Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacterial strains. The Ag–TiO2 NCs exhibited promising and superior antibacterial properties compared to TiO2 nanospheres as confirmed by the bacterial growth and inhibition zone. The improvement in the antibacterial activity was attributed to the synergistic effect of the hybrid nature of TiO2 nanoparticles in the presence of Ag.

2016 ◽  
Vol 14 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Lucia Pirvu ◽  
Isabela Nicorescu ◽  
Cristina Hlevca ◽  
Bujor Albu ◽  
Valentin Nicorescu

AbstractEpilobium genus has been confirmed as an effective source of natural antimicrobials. However, the influence of Epilobi hirsuti herba derived products on usual antibiotics activity has not been studied. In this study, several standardized Epilobi hirsuti herba extracts (EHE) were evaluated in order to asses their potential effects on usual antibiotics tested on standard Gram-positive and Gram-negative bacterial strains in vitro. The results emphasized that the bacterial strains ranged from sensitive (MIC values between 50–200 μg GAE mL-1) (S. epidermidis ATCC 12228) to very resistant (E. coli strains), E. faecalis ATCC 29212 being practically immune to EHE. In terms of synergistic interaction, Tetracycline and Ampicillin combinations lead to the most important stimulatory effects, the diameters of the inhibition zone being even 60% bigger compared to the antibiotic alone. Synergistic effects between myricetin(galloyl) derivates and Tetracycline were also revealed on P. aeruginosa and E. coli strains. Together, it clearly demonstrated not only EHE’s own antimicrobial properties, but also their capacity to influence the antimicrobial potency of some common antibiotics. These results could be useful for the area of herbal medicines and as potential candidates in managing microbial resistance, but also for physicians and pharmacists using combined antibacterial therapy.


Author(s):  
L. Rajanna ◽  
N. Santhosh Kumar ◽  
N. S. Suresha ◽  
S. Lavanya

The in vitro antibacterial assay was carried out against both Gram positive (B. cerus and S. aureus) and Gram negative (E. coli and K. pneumoniae) bacteria. Floral petals of 20 different species of plants were collected and tested for antibacterial activity. The result showed that the petals were active against both Gram positive and Gram negative. Out of 20 floral petals tested, 19 floral petals exhibited antibacterial activity against selected bacterial strains. The minimal inhibitory zone of floral petal discs against human pathogenic bacteria varies from 2 – 6 mm. Rosa carolina and Ruellia tuberosa showed significance inhibition zone for all the bacterial strains while Lantana camara does not show inhibition zone for any of these pathogenic bacteria.


2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Yohannes Kelifa Emiru ◽  
Ebrahim Abdela Siraj ◽  
Tekleab Teka Teklehaimanot ◽  
Gedefaw Getnet Amare

Objective. To evaluate the antibacterial effects of the leaf latex of Aloe weloensis against infectious bacterial strains. Methods. The leaf latex of A. weloensis at different concentrations (400, 500, and 600 mg/ml) was evaluated for antibacterial activities using the disc diffusion method against some Gram-negative species such as Escherichia coli (ATCC 14700) and Pseudomonas aeruginosa (ATCC 35619) and Gram-positive such as Staphylococcus aureus (ATCC 50080) and Enterococcus fecalis (ATCC 4623). Results. The tested concentrations of the latex ranging between 400 and 600 mg·mL−1 showed significant antibacterial activity against bacterial strain. The highest dose (600 mg/ml) of A. weloensis leaf latex revealed the maximum activity (25.93 ± 0.066 inhibition zone) followed by the dose 500 mg/ml against S. aureus. The lowest antibacterial activity was observed by the concentration 400 mg/ml (5.03 ± 0.03) against E. coli. Conclusion. The results of the present investigation suggest that the leaf latex of A. weloensis can be used as potential leads to discover new drugs to control some bacterial infections.


2014 ◽  
Vol 875-877 ◽  
pp. 87-90 ◽  
Author(s):  
Chutimon Satirapipathkul ◽  
Tanakan Chatdum

The film-forming potential of isolate of seed polysaccharide fromCassia fistulawas investigated. Increasing the glycerol concentration in the film increased elongation at break, film solubility and water vapor permeability but decreased tensile strength (TS). The film impregnated with the acetone extract ofAtractylodes lanceawas assessed for inhibition ofEscherichia coliandStaphylococcus aureus. The obtained results showed that the films exhibited antibacterial activity against both bacterial strains. Disc-diffusion assay revealed that the film resulted in a larger inhibition zone around the film onStaphylococcus aureusthan it did onEscherichia coliat the same extract concentrations (0.1 to 0.9 wt %). It can be seen that the film has satisfactory physical and antibacterial properties.


2018 ◽  
Vol 8 (5) ◽  
pp. 184-189
Author(s):  
S Saha ◽  
P Karmakar ◽  
Samir Kumar Sil

Aim: To evaluate the antibacterial activity of Parkia javanica against gram negative MDR bacterial strains which are predominantly found in skin wound. Methods: The 5 different solvent fractions of Parkia javanica were screened for antibacterial activity against gram negative multi drug resistant bacterial strains namely Enterobacter aerugenes, Pseudomonas aeruginosa and Klebsiella pneumonia by serial dilution technique. Growth kinetics study was performed and percentage of ROS production was measured by NBT reduction assay. Results: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were obtained with a range of IC100 0.08-0.31 mg/ml in case of MDR bacterial strains. The lag phase of all extract treated bacteria is extended compared to untreated cells. The normalized % of ROS is increased in presence of Parkia javanica extract. Conclusions: This study suggests that, chloroform fraction of Parkia javanica possesses promising antimicrobial substances which are having activity against MDR bacterial strains and ROS induced bacterial cell damage could be the possible mediator of its antimicrobial activity. Keywords:   Parkia javanica, antibacterial activity, MDR bacterial strains, growth curve, ROS.


2021 ◽  
Vol 14 (5) ◽  
pp. 399
Author(s):  
Lamya H. Al-Wahaibi ◽  
Amer A. Amer ◽  
Adel A. Marzouk ◽  
Hesham A.M. Gomaa ◽  
Bahaa G. M. Youssif ◽  
...  

A novel series of ciprofloxacin hybrids comprising various heterocycle derivatives has been synthesized and structurally elucidated using 1H NMR, 13C NMR, and elementary analyses. Using ciprofloxacin as a reference, compounds 1–21 were screened in vitro against Gram-positive bacterial strains such as Staphylococcus aureus and Bacillus subtilis and Gram-negative strains such as Escherichia coli and Pseudomonas aeruginosa. As a result, many of the compounds examined had antibacterial activity equivalent to ciprofloxacin against test bacteria. Compounds 2–6, oxadiazole derivatives, were found to have antibacterial activity that was 88 to 120% that of ciprofloxacin against Gram-positive and Gram-negative bacteria. The findings showed that none of the compounds tested had antifungal activity against Aspergillus flavus, but did have poor activity against Candida albicans, ranging from 23% to 33% of fluconazole, with compound 3 being the most active (33% of fluconazole). The most potent compounds, 3, 4, 5, and 6, displayed an IC50 of 86, 42, 92, and 180 nM against E. coli DNA gyrase, respectively (novobiocin, IC50 = 170 nM). Compounds 4, 5, and 6 showed IC50 values (1.47, 6.80, and 8.92 µM, respectively) against E. coli topo IV in comparison to novobiocin (IC50 = 11 µM).


Author(s):  
Festus O. Taiwo ◽  
Craig A. Obafemi ◽  
David A. Akinpelu A. Akinpelu

Aims: This studies aims at the synthesis of new heterocyclic systems and study its biological and pharmacological properties. Objective: This study was designed to synthesized some quinoxaline-2,3-dione with sulfonamide moiety, characterize the synthesized compounds, and study the antimicrobial properties of the synthesized compounds on some bacterial strains. Materials and Methods: Six quinoxaline-6-sulfonohydrazone derivatives were synthesized by reacting quinoxaline-6-sulfonohydrazine with some substituted benzaldehydes and ketones. The compounds were tested for their potential antibacterial properties. Results: All the test compounds possessed promising antibacterial property against a panel of bacterial strains used for this study. The MIC values exhibited by these compounds ranged between 0.0313 and 0.250 mg/mL. Among the compounds tested, compound 2 showed appreciable antibacterial activity. Discussion and Conclusion: The study concluded that all the compounds exhibited appreciable bactericidal effects towards all the bacterial strains, particularly, compound 2 This is an indication that such compounds possessing broad spectrum activities will be useful in formulating antimicrobial compounds which could be used to treat infections caused by pathogens that are now developing resistance against the available antibiotics.


2021 ◽  
Author(s):  
M.M. Abd El-Hady ◽  
A. Farouk ◽  
S. El-Sayed Saeed ◽  
S. Zaghloul

Abstract Medical textiles are one of the most rapidly growing parts of the technical textiles sector of the textile industry. This work was developed for biocompatible materials of curcumin / TiO2 nanocomposite fabricated on the surface of cotton fabric for medical applications. Cotton fabric was pretreated with three crosslinking agents namely, citric acid, Quat-188, and GPTMS. Applying nanocomposite on modified cotton fabric using pad-dry cure method. The chemistry and morphology of modified fabrics are examined by Fourier-transformed infrared spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. In addition, the chemical mechanism for nanocomposite modified fabric was reported. UV protection (UPF) and antibacterial properties against Gram - positive S. aureus and Gram - negative E. coli bacterial strains were investigated. The durability of fabrics to 20 washing cycles was also examined. Results demonstrated that nanocomposite modified cotton fabric exhibited superior antibacterial activity against Gram - negative bacteria that Gram - positive bacteria and excellent UV protection properties. Moreover, good durability was obtained, possibly due to the effect of the crosslinker used. Among the three pre-modification of cotton fabric, Quat-188 modified fabric reveals the highest antibacterial activity comparing with citric acid or GPTMS modified fabrics. This outcome suggested that curcumin / TiO2 nanocomposite Quatt-188 modified cotton fabric could be used in biomedical textile as antibacterial properties.


1970 ◽  
pp. 111-122
Author(s):  
Yuli Wahyu Trimulyani

Frangipani flowers (Plumeria acuminata L.) Flower is one of the plants that has antibacterial properties. Compounds that act as antibacterial are flavonoids and tannins. The purpose of this study was to prove the antibacterial activity of ethanol, chloroform, and n-hexane fractions of Frangipani flowers (Plumeria acuminata L.) flower as antibacterial against E. coli and S. aureus with Bioautography.The process of extracting plumeria acuminata L. flowers was carried out by maceration method using 70% ethanol. The extract was continued with the fractionation process with ethanol, n-hexane and chloroform solvents. Antibacterial activity testing using the well method with concentrations of 20%, 40%, 60%, 80%, 100%, positive chloramphenicol control, and negative aquadest control. The compound content test used the Thin Layer Chromatography (TLC) method with the mobile phase of chloroform: methanol: water (2:5:3) (v/v).Bioautography test using the contact method, namely the elution TLC plate, was placed on the NA medium containing a bacterial suspension for 3 hours. The biggest antibacterial test results of ethanol fraction of plumeria acuminata L. flowers were at a concentration of 100% with a diameter of inhibition zone of 13.55 mm in E. coli while 14.15 mm S. aureus. The results of TLC showed the presence of flavonoids with a price of Rf 0.70 and tannin at a price of Rf 0.68. Bioautography results showed a inhibition zone with a price of Rf 0.70 in E. coli and S. aureus which are flavonoid compounds. Based on the results of the research that has been done it can be concluded that the ethanol fraction of white frangipani flowers has antibacterial activity against E.coli and S. aureus, while the chloroform fraction and n-hexane fraction do not have antibacterial activity. The active compounds that act as antibacterial are flavonoids and tannin, but the ones that provide antibacterial effects are flavonoids with an Rf value of 0.70. Keywords: Bioautography,Escherichiacoli, Frangipani flowers, Staphylococcusaureus, TLC


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