scholarly journals ANTIBACTERIAL ACTIVITY OF SILVER NANOPARTICLES SYNTHESIZED USING CITRUS SINENSIS PEEL EXTRACT AGAINST PATHOGENS ISOLATED FROM DISEASED TOMATO (SOLANUM LYCOPERSICUM L.)

2021 ◽  
Vol 4 (1) ◽  
pp. 1-3
Author(s):  
ONYEMAECHI OBIAZIKWOR ◽  
Hakeem Olalekan SHITTU

Among all the noble nanoparticles, silver nanoparticles have gained boundless interests because of their unique properties such as chemical stability, catalytic and most important antimicrobial activities. This study was carried out to investigate the antibacterial activity of phytosynthesized silver nanoparticles against bacteria pathogens isolated from diseased tomato plant leaves. Silver nanoparticles were synthesized using Citrus peel extract and the formation of nanoparticles was monitored using spectrophotometer. Diseased tomato plant leaves were obtained from a farm located at Ovia North-East Local Government Area, Edo State, Nigeria for the isolation of bacteria pathogens. The isolated bacteria include Pseudomonas sp. and Enterobacter sp. Antibacterial testing using the phytosynthesized silver nanoparticles was carried out via the agar well diffusion method on the test isolates. Zones of inhibition of 10 and 8 mm were obtained for Enterobacter and Pseudomonas species respectively by 100 µl nanoparticles treatment after 24 hours of incubation. This indicated that the phytosynthesized silver nanoparticles have antibacterial activity against the bacterial pathogens. Further studies should be carried out to determine the mode of action of silver nanoparticles and the potential of the test nanoparticles in plant disease management. The potential of members of the genus, Enterobacter as causative agents of plant diseases should be further investigated.

2020 ◽  
Vol 21 (10) ◽  
pp. 980-989
Author(s):  
Sampath Shobana ◽  
Sunderam Veena ◽  
S.S.M. Sameer ◽  
K. Swarnalakshmi ◽  
L.A. Vishal

Aims: To evaluate the antibacterial activity of Artocarpus hirsutus mediated seed extract for nanoparticle synthesis. Background: Gastrointestinal bacteria are known for causing deadly infections in humans. They also possess multi-drug resistance and interfere with clinical treatments. Applied nanotechnology has been known to combat such infectious agents with little interference from their special attributes. Here we synthesize silver nanoparticles from Artocarpus hirsutus seed extract against two gastro-intestinal bacterial species: Enterobacter aerogenes and Listeria monocytogenes. Objective: To collect, dry, and process seeds of Artocarpus hirsutus for nanoparticle synthesis. To evaluate the morphological interaction of silver nanoparticles with bacteria. Methods: Artocarpus hirsutus seeds were collected and processed and further silver nanoparticles were synthesized by the co-precipitation method. The synthesized nanoparticles were characterized using XRD, UV, FTIR, and SEM. These nanoparticles were employed to study the antibacterial activity of nanoparticles against Enterobacter aerogenes and Listeria monocytogenes using well diffusion method. Further, morphological interaction of silver nanoparticles on bacteria was studied using SEM. Result: Silver nanoparticles were synthesized using Artocarpus hirsutus seed extract and characterization studies confirmed that silver nanoparticles were spherical in shape with 25-40 nm size. Antibacterial study exhibited better activity against Enterobacter aerogenes with a maximum zone of inhibition than on Listeria monocytogenes. SEM micrographs indicated that Enterobacter aerogenes bacteria were more susceptible to silver nanoparticles due to the absence of cell wall. Also, the size and charge of silver nanoparticles enable easy penetration of the bacterial cell wall. Conclusion: In this study, silver nanoparticles were synthesized using the seed extract of Artocarpus hirsutus for the first time exploiting the fact that Moraceae species have high phytonutrient content which aided in nanoparticle synthesis. This nanoparticle can be employed for large scale synthesis which when coupled with the pharmaceutical industry can be used to overcome the problems associated with conventional antibiotics to treat gastrointestinal bacteria.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ram Prasad ◽  
Vyshnava Satyanarayana Swamy

The unique property of the silver nanoparticles having the antimicrobial activity drags the major attention towards the present nanotechnology. The environmentally nontoxic, ecofriendly, and cost-effective method that has been developed for the synthesis of silver nanoparticles using plant extracts creates the major research interest in the field of nanobiotechnology. The synthesized silver nanoparticles have been characterized by the UV-visible spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Further, the antibacterial activity of silver nanoparticles was evaluated by well diffusion method, and it was found that the biogenic silver nanoparticles have antibacterial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 27853), Azotobacter chroococcum WR 9, and Bacillus licheniformis (MTCC 9555).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helal F. Hetta ◽  
Israa M. S. Al-Kadmy ◽  
Saba Saadoon Khazaal ◽  
Suhad Abbas ◽  
Ahmed Suhail ◽  
...  

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.


2020 ◽  
Vol 11 (4) ◽  
pp. 5382-5387
Author(s):  
Irshad Ul Haq Bhat ◽  
Maisarah Binti Alias

The approach towards green synthetic methods has been enormously encouraged to synthesise nanoparticles for various uses. In this study, the one-pot synthetic method was adapted to synthesise silver nanoparticles (AgNPs) using Melastoma malabathricum (M. malabathricum) aqueous extract. The formation of AgNPs was confirmed by observing the results obtained by optical characterisation methods. The plasma resonance band along with shoulder at 375 nm and 595 nm, respectively, in Uv-Visible spectra supported the conversion of silver (Ag) to AgNPs reduced by functional groups present in the plant extract. The size of AgNPs was 31 nm and cubic in shape as confirmed by X-ray diffractometry (XRD) using Scherer equation. X-Ray Fluorescence (XRF) results also confirmed the presence of silver. The FTIR characterisation confirmed the presence of reducing functional groups. The antibacterial activity of AgNPs against Staphylococcus aureus (S. aureus) was carried out by disc diffusion method with increasing concentration of AgNPs, and enhanced inhibition zone was observed. The AgNPs obtained can be further explored against different bacterial strains and can a potential candidate as an antibacterial agent using the green synthetic approach.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Moira Carmalita Dharsika Niluxsshun ◽  
Koneswaran Masilamani ◽  
Umaramani Mathiventhan

Wide application of nanoparticles motivates the need for synthesising them. Here, a nontoxic, eco-friendly, and cost-effective method has been established for the synthesis of silver nanoparticles using extracts of lemon peel (Citrus limon), green orange peel (Citrus sinensis), and orange peel (Citrus tangerina). The synthesised nanoparticles have been characterised using UV-visible absorptionspectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy (TEM). The UV-visible absorption spectrum of these synthesised silver nanoparticles shows an absorption peak at around 440 nm. TEM images show different shaped particles with various sizes. Furthermore, the antibacterial activity of silver nanoparticles was appraised by a well-diffusion method and it was observed that the green synthesised silver nanoparticles have an effective antibacterial activity against Escherichia coli and Staphylococcus aureus. The outcome of this study could be beneficial for nanotechnology-based biomedical applications.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mona A. Alqahtani ◽  
Monerah R. Al Othman ◽  
Afrah E. Mohammed

Abstract Recently, increase bacterial resistance to antimicrobial compounds issue constitutes a real threat to human health. One of the useful materials for bacterial control is Silver nanoparticles (AgNPs). Researchers tend to use biogenic agents to synthesize stable and safe AgNPs. The principal aim of this study was to investigate the ability of lichen in AgNPs formation and to find out their suppression ability to MDR bacteria as well as their cytotoxic activity. In the current study, lichens (Xanthoria parietina, Flavopunctelia flaventior) were collected from the south of the Kingdom of Saudi Arabia. Lichens methanolic extracts were used for conversion of Ag ions to AgNPs. Prepared biogenic AgNPs were characterized by Ultraviolet–Visible (UV–Vis) Spectroscopy, Transmission electron microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta potential and Energy-Dispersive X-ray Spectroscopy (EDS). Lichens Secondary metabolites were determined by Fourier-Transform Infrared Spectroscopy (FTIR) and Gas Chromatography–Mass Spectrometry (GC–MS). The antibacterial activity and synergistic effect of AgNPs were evaluated against pathogenic bacteria, including gram-positive; Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococcus (VRE), and gram-negative; (Pseudomonas aeruginosa, Escherichia coli) as well as the reference strains (ATCC) using the agar disk diffusion method. Cytotoxic effect of biogenic AgNPs was tested against HCT 116 (Human Colorectal Cancer cell), MDA-MB-231 (Breast cancer cell), and FaDu (Pharynx cancer cell) by MTT test. TEM imaging showed well-dispersed spherical particles of 1–40 nm size as well as zeta size showed 69–145 nm. Furthermore, FTIR and GC–MS identified various lichen chemical molecules. On the other hand, the highest antibacterial activity of AgNPs was noticed against P. aeruginosa, followed by MRSA, VRE, and E. coli. AgNPs influence on gram-negative bacteria was greater than that on gram-positive bacteria and their synergistic effect with some antibiotics was noted against examined microbes. Moreover, higher cytotoxicity for biogenic AgNPs against FaDu and HCT 116 cell line in relation to MDA-MB-231 was noted. Given the current findings, the biogenic AgNPs mediated by lichens had positive antibacterial, synergistic and cytotoxic powers. Therefore, they might be considered as a promising candidate to combat the multi-drug resistance organisms and some cancer cells.


2019 ◽  
Vol 3 (2) ◽  
pp. 61 ◽  
Author(s):  
Van Thang Nguyen ◽  
Viet Tien Vu ◽  
The Huu Nguyen ◽  
Tuan Anh Nguyen ◽  
Van Khanh Tran ◽  
...  

This work emphasizes the use of the silver decorative method to enhance the antibacterial activity of TiO2 and ZnO nanoparticles. These silver-decorated nanoparticles (hybrid nanoparticles) were synthesized using sodium borohydride as a reducing agent, with the weight ratio of Ag precursors/oxide nanoparticles = 1:30. The morphology and optical properties of these hybrid nanoparticles were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, and UV-Vis spectroscopy. The agar-well diffusion method was used to evaluate their antibacterial activity against both Staphylococcus aureus and Escherichia coli bacteria, with or without light irradiation. The TEM images indicated clearly that silver nanoparticles (AgNPs, 5–10 nm) were well deposited on the surface of nano-TiO2 particles (30–60 nm). In addition to this, bigger AgNPs (<20 nm) were dispersed on the surface of nano-ZnO particles (30–50 nm). XRD patterns confirmed the presence of AgNPs in both Ag-decorated TiO2 and Ag-decorated ZnO nanoparticles. UV-Vis spectra confirmed that the hybridization of Ag and oxide nanoparticles led to a shift in the absorption edge of oxide nanoparticles to the lower energy region (visible region). The antibacterial tests indicated that both oxide pure nanoparticles did not exhibit inhibitory effects against bacteria, with or without light irradiation. However, the presence of AgNPs in their hybrids, even at low content (<40 mg/mL), leads to a good antibacterial activity, and higher inhibition zones under light irradiation as compared to those in dark were observed.


2018 ◽  
Vol 29 (2) ◽  
pp. 37-41
Author(s):  
M Iqbal Hossain ◽  
M Anwar Habib ◽  
Nazimuddin Ahmed

This quasi experimental study was designed to evaluate antibacterial activity of chemically synthesized silver nanoparticles (AgNPs) from silver nitrate (AgNO3) solutions on gram negative bacteria like E.Coli using disc diffusion method. Different concentrations of AgNPs, AgNO3 and reference drug ciprofloxacin were used to find out the antibacterial activity which revealed that AgNPs possessed significant antibacterial effect compared to AgNO3 solutions but relatively less antibacterial effect than that of ciprofloxacin. So chemical synthesis guided AgNPs may have some antibacterial effects.TAJ 2016; 29(2): 37-41


Author(s):  
S. Kaviya ◽  
J. Santhanalakshmi ◽  
B. Viswanathan ◽  
J. Muthumary ◽  
K. Srinivasan

2020 ◽  
Vol 7 (4) ◽  
pp. 109-113
Author(s):  
Sahar Baie ◽  
Ania Ahani Azari ◽  
Teena Dadgar

Background: This descriptive cross-sectional study was conducted to determine the antibacterial activity of Lactobacillus strains isolated from buffalo milk and yogurt in Aliabad-e Katul city, Golestan province, north-east of Iran. Methods: Raw milk and yogurt samples were collected and cultured on MRS medium by incubating anaerobically at 37°C for 48 hours. The suspected colonies were identified on the basis of Gram staining, biochemical tests, and carbohydrates fermentation. The antibacterial activity of the cell-free supernatant (CFS) extracted from Lactobacillus strains was determined using the agar well diffusion method against standard strains of Escherichia coli ATCC 11303, Klebsiella pneumoniae ATCC 13883, and Pseudomonas aeruginosa ATCC 15442 as well as gram-negative uropathogens previously isolated from patients with urinary tract infections (UTIs). Three isolates of E. coli (E1, E2, and E3), two isolates of P. aeruginosa (P1 and P2), and two isolates of K. pneumoniae (K1 and K2) were used in this study. Results: A total of 19 Lactobacillus strains were identified as L. plantarum, L. casei, L. acidophilus, and L. helveticus. Based on the results of antibacterial activity test, the isolates had the highest and lowest inhibitory effects on the E. coli and K. pneumoniae isolates, respectively. Among the isolates, only L. casei isolates showed inhibitory activity against K. pneumoniae isolates. Conclusions: In this study, Lactobacilli from buffalo milk and yogurt demonstrated a good inhibitory activity against E. coli as a common cause of urinary tract infection. Therefore, further studies are recommended to elucidate their potential for being used as an alternative to antibiotic therapy.


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