scholarly journals Bactericides Properties of Chitosan Metal Quantum Dots Microbial Pathogenicity Against E. coli, S. aureus, and S. Typhi

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Galo Cárdenas-Triviño ◽  
María J. Saludes-Betanzo ◽  
Luis Vergara-González

The nanotechnology is considered as a tool to overcome antibiotic-resistant infections. The aim of this study was to investigate the antibacterial properties of quantum dots (QDs) of Au, Ag, and Cu supported in chitosan against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), and Salmonella Typhi (ATCC 9993) strains. The QDs were synthesized by the method (Chemical Liquid Deposition, CLD) using 2-ethoxyethanol as solvent (1×10−3 M approximate dispersion concentration). Then, NPs supported in chitosan were synthesized by solvated metal atom dispersion (SMAD) in two concentrations, labelled [A] and [B] (0.05 and 0.1 g/L) for each metal with chitosan resulting in an average size of Au 10±2.0, Ag 6±1.3, and Cu 10±2.4 nm, respectively. Several other techniques were performed such as TEM, SEM/EDX, TGA, DSC, and FT-IR for characterizing QDs. The antibacterial assay was performed with 8 agents on cultures of E. coli, S. aureus, and S. Typhi by disk diffusion, broth macrodilution, and determining death curve to the most sensitive pathogen. The antibacterial effect of the nanoparticles was compared using the diameter of growth inhibition zone by agar disk diffusion and through the minimal inhibitory concentration (MIC) and minimal bactericide concentration (MBC) obtained by macrodilution in batch culture with an initial inoculum of 5×105 CFU/mL. The highest bactericidal effect was obtained with nanoparticles of Au, Ag, and Cu (0.1 g/L) with MIC and MBC of 200 and 400 mg/mL, respectively. The greatest bactericidal effect considering the three pathogens turned out to be Ag QDs (0.05 and 0.1 g/L). A bactericidal effect of metal nanoparticles is affected mainly by the electronegativity, the concentration of nanoparticles, and the bacterial age culture.

2020 ◽  
Author(s):  
Leyla Mojtabavi ◽  
Amir Razavi

AbstractIn this work, we studied the effects of copper incorporation in the composition of bioactive glass. Three different glass compositions were synthesized with 0, 3, and 6 mol% of copper addition. X-Ray Diffraction (XRD) patterns confirmed that an amorphous microstructure was obtained for all three glass compositions. Results from Differential Thermal Analysis (DTA) showed that the copper addition in the glass lowers the glass transition temperature, from 646°C to 590°C when added at 6 mol%. X-ray Photoelectron (XPS) survey and high-resolution scans were performed to study the structural effects of copper addition in the glass. Results indicated that the incorporation of copper changes the ratio of bridging to non-birding oxygens in the structure. Glasses were further analyzed for their structure with Nuclear Magnetic Resonance (NMR) spectroscopy, which indicated that copper acts as a network modifier in the glass composition and copper-containing glasses show a less connected microstructure. Antibacterial efficacy of the glasses was analyzed against E. coli and S. epidermis. Copper-containing glasses showed a significantly higher inhibition zone compared to control glass. The glass with 6 mol% copper, exhibited inhibition zones of 9 and 16mm against E. coli and S. epidermis bacteria, respectively.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Olga V. Zakharova ◽  
Anna Yu. Godymchuk ◽  
Alexander A. Gusev ◽  
Svyatoslav I. Gulchenko ◽  
Inna A. Vasyukova ◽  
...  

Suspensions of Cu nanoparticles are promising for creating the new class of alternative antimicrobial products. In this study we examined copper nanoparticles of various sizes obtained by the method of wire electric explosion: nanopowder average size 50 nm (Cu 50) and 100 nm (Cu 100). The paper presents the complex study of the influence of physicochemical properties such as particle size and concentration of the freshly prepared and 24-hour suspensions of Cu nanoparticles in distilled water and physiological solution upon their toxicity to bacteriaE. coliM-17. Ionic solution of Cu2+and sodium dichloroisocyanurate was used for comparison study. It has been shown that decrease in the nanoparticle size leads to changes in the correlation between toxicity and concentration as toxicity peaks are observed at low concentrations (0.0001⋯0.01 mg/L). It has been observed that antibacterial properties of Cu 50 nanoparticle suspensions are ceased after 24-hour storage, while for Cu 100 suspensions no correlation between antibacterial properties and storage time has been noted. Cu 100 nanoparticle suspensions at 10 mg/L concentration display higher toxicity at substituting physiological solution for water than Cu 50 suspensions. Dependence of the toxicity on the mean particle aggregates size in suspension was not revealed.


PHARMACON ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 834
Author(s):  
Eunike Pelealu ◽  
Defny S. Wewengkang ◽  
Surya Sumantri Abdullah

ABSTRACTSponges are one of the biota components that make up coral reefs which are quite widely distributed. The metabolite content in the sponge can ward off and inhibit the pathogenic bacteria that interfere with it. This study aims to determine the activity of inhibiting bacterial growth from the extract and fraction of Leucetta chagosensis sponge against the growth of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. The samples were extracted using the maceration method with 95% ethanol solvent and then fractionated using 3 solvents with different polarity levels, namely methanol, n-hexane and chloroform. Activity test using the disk diffusion agar method of Kirby and Bauer. Only the MeOH fraction was able to inhibit the growth of E. coli bacteria with an average inhibition zone of 6.88 mm. Whereas for S.aureus bacteria extracts and all fractions showed activity to inhibit bacterial growth with an average inhibition zone of EtOH (6.61 mm), CHCI3 (6.68 mm), n-hexane (7.83 mm) and MeOH (8.00 mm), respectively. All activities that are shown are categorized as weak (weak).Keywords: Antibacterial, Leucetta chagosensis, Staphylococcus aureus, Escherichia coli ABSTRAKSpons merupakan salah satu komponen biota penyusun terumbu karang yang penyebarannya cukup luas. Kandungan metabolit yang ada di dalam spons dapat menangkal dan menghambat bakteri patogen pengganggunya.  Penelitian ini bertujuan untuk melihat aktivitas menghambat pertumbuhan bakteri dari ekstrak dan fraksi spons Leucetta chagosensis. terhadap pertumbuhan bakteri Gram positif Staphylococcus aureus dan Gram negatif Escherichia coli. Sampel di ekstraksi menggunakan metode maserasi dengan pelarut etanol 95% lalu di fraksinasi dengan menggunakan 3 pelarut dengan tingkat kepolaran yang berbeda yaitu metanol, n-heksan dan kloroform. Uji aktivitas menggunakan metode disk diffusion agar Kirby dan Bauer.  Hanya fraksi MeOH yang mampu menghambat pertumbuhan bakteri E.coli dengan zona hambat rata-rata 6,88 mm. Sedangkan terhadap bakteri S.aureus ekstrak dan semua fraksi menunjukan aktifitas menghambat pertumbuhan bakteri dengan rata-rata zona hambat masing-masing EtOH (6,61 mm), CHCl3 (6,68 mm), n-Heksan (7,83 mm), dan MeOH (8,00 mm). Semua aktivitas yang ditunjukan dikategorikan lemah (weak).Kata kunci : Antibakteri, Leucetta chagosensis, Staphylococcus aureus,  Escherichia coli


2021 ◽  
Vol 9 (2) ◽  
pp. 75
Author(s):  
Luthfiah Luthfiah ◽  
Dwi Setyati ◽  
Sattya Arimurti

Dumortiera hirsuta is one of the liverworts that can be used as a medicinal to prevent infection by pathogenic bacteria. The content of secondary metabolites of D. hirsuta has potential as antibacterial properties includes flavonoids, alkaloids and steroids. This research is to analyze the antibacterial activity of moss D. hirsuta against pathogenic bacteria that will be beneficial to humans. Liverworts of D. hirsuta were extracted using ethyl acetate solvent and tested against three types of pathogenic bacteria using the agar well-diffusion method. The results of this study indicated that the ethyl acetate extract of D. hirsuta at 100% concentration could inhibit the growth of Escherichia coli, Staphylococcus aureus, and Salmonella typhi bacteria. The range of antibacterial activity categories of the ethyl acetate extract of D. hirsuta to E. coli, S. aureus, and S. typhi between weak to moderate.


Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 72
Author(s):  
Mohamad M. Ahmad ◽  
Hicham Mahfoz Kotb ◽  
Shehla Mushtaq ◽  
Mir Waheed-Ur-Rehman ◽  
Christopher M. Maghanga ◽  
...  

This article outlines the preparation of manganese-doped copper nanoparticles (Mn + Cu NPs) using Vinca rosea (L.) leaf extract as a convenient and environmentally friendly substance. UV–vis, FT–IR, XRD, SEM–EDAX, and DLS instrumental techniques were employed to describe the physical and chemical properties of synthesized V. rosea extract-mediated Vr-Mn + Cu NPs. The synthesized Vr-Mn + Cu NPs were observed to be monodispersed and spherical, with an average size of 412 nm. The plant extract includes a variety of phytochemical components. The Vr-Mn + Cu NPs also have potential antioxidant and antibacterial properties against selected pathogens. The green synthesized Vr-Mn + Cu NPs showed a maximum inhibition zone of 16.33 ± 0.57 mm against E. coli. For dye degradation, MR, EBT, and MO showed the highest degradation percentage capabilities with Vr-Mn + Cu NP-based adsorbents, which were determined to be 78.54 ± 0.16, 87.67 ± 0.06, and 69.79 ± 0.36. The results clearly show that biosynthesized Vr-Mn + Cu NPs may be employed as an antioxidant, antibacterial, photocatalytic dye degradation, and catalytic agent, as well as being ecologically benign.


2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Lucía Arévalo-Híjar ◽  
Miguel Ángel Aguilar-Luis ◽  
Stefany Caballero-García ◽  
Néstor Gonzáles-Soto ◽  
Juana Del Valle-Mendoza

Objective. To evaluate antibacterial and cytotoxic effect of 2 methanolic extracts of Azadirachta indica and Moringa oleifera against strains of Enterococcus faecalis (ATCC 29212) in vitro. Methods. The methanolic extracts of Azadirachta indica and Moringa oleifera were prepared in vitro. The antibacterial effect of the extracts against Enterococcus faecalis was evaluated using the agar diffusion technique. The minimum inhibitory concentration (MIC) was determined using the microdilution method and the cytotoxicity using the cellular line MDCK. Results. The methanolic extract with the most antibacterial effect during the first 24 and 48 hours against Enterococcus faecalis was Moringa oleifera, evidencing a growth inhibition zone of 35.5 ± 1.05 and 44.83 ± 0.98, respectively. The MIC for both extracts was 75 µg/ml. The bactericidal effect of the Azadirachta indica extract was found at a concentration of 25 µg/ml and a concentration of 75 µg/ml for Moringa extract. Conclusions. In conclusion, we demonstrated that the methanolic extract of Azadirachta indica and Moringa oleifera both have an antibacterial effect against Enterococcus faecalis strains during the first 24 and 48 hours. None of the extracts exhibited toxicity against the cell lines under low concentrations.


2018 ◽  
Vol 29 (6) ◽  
pp. 645-650 ◽  
Author(s):  
Oumar Mahamat ◽  
Tume Christopher ◽  
Njouonkou Andre-Ledoux ◽  
Amadoh Jude ◽  
Nfor Ndiane ◽  
...  

Abstract Background Globally, Termitomyces letestui is used by different communities to treat various illnesses, including bacterial infection, although with limited scientific evidence. The current study aims to assess the immunomodulatory and antibacterial properties of the water extract of a wild mushroom, T. letestui in mice model. Methods The base study was completed following the standard methods and procedures using white mice Mus musculus. The immunomodulatory was investigated for humoral and cell-mediated response in both the normal and dexamethasone-immunosuppressed mice. An immunostimulatory drug, levamisole, was used as reference. The treatment was done daily and the extract doses of 250 and 500 mg/kg bwt were used. Delayed-type hypersensitivity reaction (DTH), mice lethality rate and hemagglutination antibody titer were determined. Disc diffusion assay was performed using the Muller-Hinton agar to assess the effect against Escherichia coli and Staphylococcus aureus. The statistical analysis was performed using GraphPad prism 5.0 a Software. Results T. letestui water extract (TLAE) provided significant inhibition zones against E. coli and S. aureus. TLAE=, along with the antigen (Salmonella typhi) showed a significant increase in the circulating antibody titer and reduced the lethality rate in mice. The extract also showed significant increase in the DTH response against S. typhi. Conclusions This preliminary study demonstrated that TLAE caused a significant immunostimulatory effect on both the cell-mediated and humoral immune systems in the mice and antibacterial property against E. coli and S. aureus.


2015 ◽  
Vol 43 (2) ◽  
pp. 327-334 ◽  
Author(s):  
Mihaela NICULAE ◽  
Laura STAN ◽  
Emoke PALL ◽  
Anamaria Ioana PAȘTIU ◽  
Iulia Maria BALACI ◽  
...  

The study was aimed to characterize the chemical composition and the antimicrobial activity of Romanian propolis ethanolic extracts (EEP) against antibiotic-sensitive and antibiotic-resistant E. coli strains isolated from bovine mastitis. The preliminary antimicrobial screening was performed by a disk diffusion method, followed by determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) based on broth microdilution assay; further, the synergistic action of propolis with antimicrobial drugs was assessed by a disk diffusion method on agar containing subinhibitory concentrations of propolis. For the chemical characterisation of EEP, the flavonoids (flavones/flavonols, flavanones/dihydroflavonols) and total phenolics were evaluated by spectrophotometric methods. The phenolic compounds of these extracts were also determined using HPLC. The results indicated for Romanian propolis ethanolic extracts the typical poplar composition profile with flavonoids and phenolic acids as main biological active compounds, with chromatographic analysis data confirmed also spectrophotometrically. In addition, positively correlated with the chemical composition, a strong antimicrobial efficacy was exhibited towards E. coli strains, along with interesting synergistic interaction with antibiotics that can be further investigated to obtain propolis-based formulation with antibacterial properties. Subsequent in vitro and in vivo studies evaluating the safety and efficacy are intended to consider propolis in veterinary therapeutic protocols.


2021 ◽  
Vol 21 (1) ◽  
pp. 281
Author(s):  
Muhammad Zaidan Tsani Ariandi ◽  
Meiskha Bahar ◽  
Hany Yusmaini ◽  
Fajriati Zulfa ◽  
Cut Fauziah ◽  
...  

Actinomycetes are found in soils with loose, humus, dry characteristics and around plant roots. Actinomycetes produce secondary metabolite compounds as antibacterial. Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi are Gram negative bacteria that can cause infection in humans. This study aims to determine the ability of the Actinomycetes metabolite filtrate from Bogor Botanical Gardens as an antibacterial agent against the growth of E. coli, P.aeruginosa and S. typhi in vitro. This study used an experimental design with samples of Actinomycetes isolats originating from the Bogor Botanical Gardens soil using the disc diffusion method on Muller Hinton Agar (MHA) media by looking at the clear zone of bacterial growth around the disc paper. Of the three concentration groups, namely 50%, 60%, and 70%, the largest average inhibition zone is found at a concentration of 70% with the average for the three test bacteria E. coli, P.aeruginosa and S. typhi respectively: 4.23 mm; 3.0 mm and 8.43 mm. The results of the Kruskal - Wallis test with p value = 0.01 showed that there was an effect of the Actinomycetes metabolite filtrate on the growth of the three tested bacteria as antibacterials.  


2020 ◽  
Vol 13 (7) ◽  
pp. 3193-3201
Author(s):  
Flore Nguemaim Ngoufo ◽  
Gerald Ngo Teke ◽  
Amslem Che ◽  
Henri Lucien Fouamno Kamga

Typhoid fever is an infectious disease that has been a public health concern for millennia. The use of herbal preparations is getting popularity, with an estimated 80% of the world’s population still depending on it for the management of various diseases including typhoid fever. However, data concerning their quality, safety and efficacy is not readily available. Our aim was to determine the in vitro efficacy of some commercially available herbal preparations used in the treatment of typhoid fever in Bamenda Municipality. Five herbal preparations indicated for the treatment of typhoid fever (coded P1 to P5) were bought from various outlets of the herbal producers and serial dilutions made and screened for their activities against clinical isolates of Salmonella Typhi and Salmonella Paratyphi using the agar well diffusion and dilution methods. The bacterial growth inhibition zone diameters of the herbal preparations were measured with a transparent ruler and compared with those of some standard antibiotics (ciprofloxacin and ceftriaxone). Two of the herbal preparations (P1 & P2) showed inhibition zone diameters against S. Typhi (20 and 14 mm respectively) while the rest (P3, P4 & P5) were inactive. P1 showed minimal activity on S. Paratyphi while the rest of the herbal preparations (P2, P3, P4 and P5) were inactive at all tested concentrations. The difference between the value of the inhibition zone diameters of the herbal preparations and that of the standard antibiotics on both S. Typhi and S. Paratyphi was statistically significant (p<0.05). It was found out that most of the herbal preparations showed no activity against the tested bacterial isolates contrary to their label bogus claims.Keywords: Antibacterial activity, Typhoid fever, Herbal preparations, in vitro, Bamenda-Cameroon.


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