scholarly journals Assessment of Polarized Piezoelectric SrBi4Ti4O15 Nanoparticles as an alternative antibacterial agent

2021 ◽  
Author(s):  
Subhasmita Swain ◽  
Tapash Ranjan Rautray

AbstractStrontium bismuth titanate nanoparticles (SrBi4Ti4O15/SBT NPs,) and their polarized counterparts were prepared to assess their antibacterial efficacy on biomaterials. The structural properties of the SBT NPs were performed by X-ray diffraction and the antibacterial efficacy was evaluated against Staphyllococcus aureus (S. aureus) pathogenic bacteria. Significant antibacterial activity of polarized SBT specimen was observed against S. aureus bacteria. Results presented in this work confirmed that polarized SBT can effectively combat bacterial growth and prevent biofilm formation activity of pathogenic bacteria and hence they can be used as alternative antimicrobial agents.

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 89 ◽  
Author(s):  
Shahabe Abullais Saquib ◽  
Nabeeh Abdullah AlQahtani ◽  
Irfan Ahmad ◽  
Mohammed Abdul Kader ◽  
Sami Saeed Al Shahrani ◽  
...  

Background: In the past few decades focus of research has been toward herbal medicines because of growing bacterial resistance and side effects of antimicrobial agents. The extract derived from the plants may increase the efficacy of antibiotics when used in combination against pathogenic bacteria. In the current study, the synergistic antibacterial efficacy of plant extracts in combination with antibiotics has been assessed on selected periodontal pathogens. Methods: Ethanolic extracts were prepared from Salvadora persica (Miswak) and Cinnamomum zeylanicum (Ceylon cinnamon), by the soxhalate method. Plaque samples were collected from clinical periodontitis patients to isolate and grow the periodontal pathobionts under favorable conditions. Susceptibility of bacteria to the extracts was assessed by gauging the diameter of the inhibition zones. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined against each bacterium. Synergistic activity of plants extract in combination with antibiotics against the bacteria was also assessed by measuring the diameter of the inhibition zones. Results: Ethanolic extract of both the plants showed an inhibitory effect on the proliferation and growth of all four strains of periodontal pathobionts. Maximum antibacterial activity was exhibited by C. zeylanicum against Tannerella forsythia (MIC = 1.56 ± 0.24 mg/mL, MBC = 6.25 ± 0.68 mg/mL), whereas among all the studied groups the minimum activity was reported by C. zeylanicum against Aggregatibacter actinomycetemcomitans the (MIC = 12.5 ± 3.25 mg/mL, MBC = 75 ± 8.23 mg/mL). Combination of herbal extracts with different antibiotics revealed a synergistic antibacterial effect. The best synergism was exhibited by S. persica with metronidazole against A. actinomycetemcomitans (27 ± 1.78). Conclusions: Current in vitro study showed variable antibacterial activity by experimented herbal extracts against periodontal pathobionts. The synergistic test showed significant antibacterial activity when plant extracts were combined with antibiotics.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gebretinsae Yeabyo Nigussie ◽  
Gebrekidan Mebrahtu Tesfamariam ◽  
Berhanu Menasbo Tegegne ◽  
Yemane Araya Weldemichel ◽  
Tesfakiros Woldu Gebreab ◽  
...  

We report in this paper antibacterial activity of Ag-doped TiO2 and Ag-doped ZnO nanoparticles (NPs) under visible light irradiation synthesized by using a sol-gel method. Structural, morphological, and basic optical properties of these samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrum, and UV-Vis reflectance. Room temperature X-ray diffraction analysis revealed that Ag-doped TiO2 has both rutile and anatase phases, but TiO2 NPs only have the anatase phase. In both ZnO and Ag-doped ZnO NPs, the hexagonal wurtzite structure was observed. The morphologies of TiO2 and ZnO were influenced by doping with Ag, as shown from the SEM images. EDX confirms that the samples are composed of Zn, Ti, Ag, and O elements. UV-Vis reflectance results show decreased band gap energy of Ag-doped TiO2 and Ag-doped ZnO NPs in comparison to that of TiO2 and ZnO. Pathogenic bacteria, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, were used to assess the antibacterial activity of the synthesized materials. The reduction in the viability of all the three bacteria to zero using Ag-doped ZnO occurred at 60 μg/mL of culture, while Ag-doped TiO2 showed zero viability at 80 μg/mL. Doping of Ag on ZnO and TiO2 plays a vital role in the increased antibacterial activity performance.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1743
Author(s):  
Majid Rasool Kamli ◽  
Maqsood Ahmad Malik ◽  
Vartika Srivastava ◽  
Jamal S. M. Sabir ◽  
Ehab Hussain Matter ◽  
...  

This study presents an inexpensive, eco-friendly, and simple green synthesis of ZnO nanoparticles using Origanum vulgare extract. These nanoparticles are non-hazardous, environmentally friendly, and cheaper than other methods of biosynthesis. Ongoing research determines the role of phytochemicals in the fabrication and biosynthesis of ZnO NPs and their role in antibacterial activity and biomedical applications. Characterizations by fourier transform infrared spectroscopy (FTIR), diffuse reflectance UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) determine the successful biosynthesis of ZnO NPs. Meanwhile, TEM and X-ray diffraction studies approximated the spherical morphology and crystalline nature of biosynthesized ZnO NPs of nano size in the range of 20–30 nm. The global increase in drug resistance necessitates the search for new drugs with different mechanisms of action. Quorum sensing (QS), a cell-to-cell communication, has gained attention as an emerging drug target. It controls numerous biochemical processes in bacteria, which are essential for their survival and pathogenicity. The potential of nanomedicines has also been tested to synthesize new antibiotics to tackle drug resistance. ZnO NPs were explored for their antibacterial, antiquorum sensing, and antibiofilm activities with a bioreporter strain of Chromobacterium violaceum. Susceptibility testing results indicated the potential antibacterial activity of ZnO NPs with a minimum inhibitory concentration (MIC) of 4 µg/mL and minimum bactericidal concentration (MBC) of 16 µg/mL. Antiquorum-sensing assays revealed that these nanoparticles inhibit quorum sensing with minimum antiquorum sensing activity (MQSIC) of 1 µg/mL, without causing any bacterial growth inhibition. In addition, ZnO NPs inhibit biofilm formation at inhibitory and higher concentrations. RT-qPCR results supported the downregulation of the quorum sensing genes when C. violaceum was treated with ZnO NPs. The outcomes of this study are promising with regard to the biofilm and quorum sensing, emphasizing the potential applications of ZnO NPs against bacterial communication and biofilm formation.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
S. Rajeshkumar ◽  
C. Malarkodi

Biosynthesis of silver nanoparticles usingPlanomicrobiumsp. and to explore the antibacterial activity against food borne pathogenic bacteriaBacillus subtilis, (3053)Klebsiella planticola(2727)Klebsiella pneumoniae(MAA)Serratia nematodiphila(CAA) andEscherichia coli. In the current studies, 1 mM of silver nitrate was added into 100 mL ofPlanomicrobiumsp. culture supernatant. The bioreduction of pure AgNO3was characterized by UV-visible spectroscopy, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy-dispersive analysis (EDS), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) analysis. The formation of silver nanoparticles was confirmed by the presence of an absorption peak at 400 nm using UV-visible spectrophotometry. The morphology and size of the silver nanoparticles was monitored by TEM and SEM. Crystal structure was obtained by carrying out X-ray diffraction studies and it showed face centered cubic (FCC) structure. The bactericidal effect of silver nanoparticles was compared based on diameter of inhibition zone in well method. Bacterial sensitivity to nanoparticles a key factor in manufacture the suitable for long life application in food packaging and food safety. Food safety is a worldwide health goal and the food borne diseases get a main disaster on health. Therefore, controlling of bacterial pathogens in food is credit of harms associated to health and safety.


Author(s):  
C. P. Chandrappa ◽  
N. Chandrasekar ◽  
M. Govindappa ◽  
Chaitra Shanbhag ◽  
Uttam Kumar Singh ◽  
...  

Objective: The present study outline the plant-mediated synthesis of silver nanoparticles (AgNPs) using leaf extract Simaroubaglauca, which act as both reducing and stabilizing agent.Methods: Formation of silver nanoparticles was confirmed by primarily by Ultraviolet/visible spectroscopy. X-ray diffraction studies revealed the crystallinity of the nanoparticles. The scanning electron microscopy was carried out to determine the mean particle size, as well as the morphology of the NPs and the composition of elements, was studied with Energy Dispersive X-ray analysis (EDS).Results: The silver nanoparticles were spherical in shape with a mean size of 23 nm. The EDS showed strong optical absorption peak at 3keV and it was confirmed the formation of AgNPs. The synthesised AgNPs further utilized for the evaluation of antibacterial activity and shown significant antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Enterobacter and Klebsiella pneumonia at 50 µg/ml and 100µg/ml concentrations.Conclusion: The synthesised silver nanoparticles have been characterised by UV-vis, SEM-EDAX and XRD to determine the sizes and shapes of the silver nanoparticles.


2021 ◽  
pp. 088391152110142
Author(s):  
Velu Gomathy ◽  
Venkatesan Manigandan ◽  
Narasimman Vignesh ◽  
Aavula Thabitha ◽  
Ramachandran Saravanan

Biofilms play a key role in infectious diseases, as they may form on the surface and persist after treatment with various antimicrobial agents. The Staphylococcus aureus, Klebsiella pneumoniae, S. typhimurium, P. aeruginosa, and Escherichia coli most frequently associated with medical devices. Chitosan sulphate from marine litter (SCH-MW) was extracted and the mineral components were determined using atomic absorption spectroscopy (AAS). The degree of deacetylation (DA) of SCH was predicted 50% and 33.3% in crab and shrimp waste respectively. The elucidation of the structure of the SCH-MW was portrayed using FT-IR and 1H-NMR spectroscopy. The molecular mass of SCH-MW was determined with Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). The teratogenicity of SCH-MW was characterized by the zebrafish embryo (ZFE) model. Antimicrobial activity of SCH-MW was tested with the agar well diffusion method; the inhibitory effect of SCH-MW on biofilm formation was assessed in 96 flat well polystyrene plates. The result revealed that a low concentration of crab-sulfated chitosan inhibited bacterial growth and significantly reduced the anti-biofilm activity of gram-negative and gram-positive bacteria relatively to shrimp. It is potentially against the biofilm formation of pathogenic bacteria.


2015 ◽  
Vol 61 (7) ◽  
pp. 487-494 ◽  
Author(s):  
Devendra H. Dusane ◽  
Che O’May ◽  
Nathalie Tufenkji

Chromobacterium violaceum is an opportunistic pathogen that causes infections that are difficult to treat. The goal of this research was to evaluate the effect of selected tannins (tannic acid (TA) and gallic acid (GA)) on bacterial growth, motility, antibiotic (carbenicillin, tetracycline) susceptibility, and biofilm formation. Both tannins, particularly TA, impaired bacterial growth levels and swimming motilities at sub-minimum inhibitory concentrations (sub-MICs). In combination with tannins, antibiotics showed increased MICs, suggesting that tannins interfered with antibacterial activity. Sub-MICs of tetracycline or TA alone enhanced biofilm formation of C. violaceum; however, in combination, these compounds inhibited biofilm formation. In contrast, carbenicillin at sub-MICs was effective in inhibiting C. violaceum biofilm formation; however, in combination with lower concentrations of TA or GA, biofilms were enhanced. These results provide insights into the effects of tannins on C. violaceum growth and their varying interaction with antibiotics used to target C. violaceum infections.


2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.


2011 ◽  
Vol 366 ◽  
pp. 404-407
Author(s):  
Li Hua Wang

The block single-crystals of taurine were obtained, and its structure was determined by single-crystal X-ray diffraction. The single-crystal X-ray analysis of taurine reveals that the crystal belongs monoclinic, space group P2(1)/c with a = 0.52824(10) nm, b = 1.1647(8) nm, c = 0.79236(13) nm, ß = 94.0850(10). The magnesium complex with taurine has been synthesized in ethanol. The antibacterial assay of the Mg (II) complex was measureed using a modified version of the 2-fold serial dilution method. The results show that the complex shows considerable antibacterial activity against escherichia coli, bacillus subtilis and staphylococcus white.


Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1423
Author(s):  
Nicola Mangieri ◽  
Roberto Foschino ◽  
Claudia Picozzi

Shiga toxin-producing Escherichia coli are pathogenic bacteria able to form biofilms both on abiotic surfaces and on food, thus increasing risks for food consumers. Moreover, biofilms are difficult to remove and more resistant to antimicrobial agents compared to planktonic cells. Bacteriophages, natural predators of bacteria, can be used as an alternative to prevent biofilm formation or to remove pre-formed biofilm. In this work, four STEC able to produce biofilm were selected among 31 different strains and tested against single bacteriophages and two-phage cocktails. Results showed that our phages were able to reduce biofilm formation by 43.46% both when used as single phage preparation and as a cocktail formulation. Since one of the two cocktails had a slightly better performance, it was used to remove pre-existing biofilms. In this case, the phages were unable to destroy the biofilms and reduce the number of bacterial cells. Our data confirm that preventing biofilm formation in a food plant is better than trying to remove a preformed biofilm and the continuous presence of bacteriophages in the process environment could reduce the number of bacteria able to form biofilms and therefore improve the food safety.


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