scholarly journals Presence of Silver Resistance Genes is not associated with Minimum Inhibitory Concentration of Silver Nanoparticles against Staphylococcus aureus and Escherichia coli

2020 ◽  
Vol 14 (4) ◽  
pp. 7-12
Author(s):  
ezzat allah ghaemi ◽  
fahimeh azadi ◽  
naeme javid ◽  
hanieh bagheri ◽  
◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdulkader Masri ◽  
Naveed Ahmed Khan ◽  
Muhammad Zarul Hanifah Md Zoqratt ◽  
Qasim Ayub ◽  
Ayaz Anwar ◽  
...  

Abstract Backgrounds Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study. Results 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P< 0.01) in both E. coli K1 treated with Hesperidin conjugated silver nanoparticles and E. coli K1 treated with silver alone, compared to untreated E. coli K1. Of note, the expression levels of cation efflux genes (cusA and copA) and translocation of ions, across the membrane genes (rsxB) were found to increase 2.6, 3.1, and 3.3- log FC, respectively. Significant regulation was observed for metabolic genes and several genes involved in the coordination of flagella. Conclusions The antibacterial mechanism of nanoparticles maybe due to disruption of the cell membrane, oxidative stress, and metabolism in E. coli K1. Further studies will lead to a better understanding of the genetic mechanisms underlying treatment with nanoparticles and identification of much needed novel antimicrobial drug candidates.


2020 ◽  
Vol 12 (1) ◽  
pp. 71-75
Author(s):  
A.M. Aliyu ◽  
S.J. Oluwafemi ◽  
S. Kasim

All over the world, hundreds of plants have been identified based on researchers and experimental evidence as good sources of medicinal agents. The bioactive components (phytochemicals) of both the seeds and pulp of Cola milleni were extracted using ethanol as solvent. The bioactive components detected were alkaloids, tanins, saponins, cardiac glycosides, carbohydrates, sterols, resins and terpenes while Flavonoids, anthraquinones, anthracyanides and phenol were not detected for both the seed and pulps. Antimicrobial activity of the ethanol extract (Seed and pulp) against Staphylococcus aureus, Escherichia coli and Penicillium notatum was carried out using standard techniques. Staphylococcus aureus had the highest zone of inhibition for pulp having a range of 9.7mm±0.58mm - 19.7mm±2.52mm while Penicllium notatum had the least with 0.00mm. S.aureus also had the highest zone of inhibition range of 14.3mm±2.08mm - 21.3mm±1.53mm for the seed extract while penicillium had the least inhibition range of 5.0mm±1.00mm - 5.7mm±0.58. E.coli showed the highest minimum inhibitory concentration with ethanol extract of the pulp (160mg/ml) while penicillium notatum was not reactive. The minimum inhibitory concentration of seed against penillium notatum was the highest (160mg/ml) while staphylococcus aureus showed the lowest of 40mg/ml. The antimicrobial activity is as a result of the presence of phytochemicals detected, which suggest the use of the plant for the treatment of diseases caused by these organisms. Key words: Cola millenii, Phytochemical, Antimicrobial activity, Bacteria, Fungi


DICP ◽  
1989 ◽  
Vol 23 (6) ◽  
pp. 456-460
Author(s):  
Michael N. Dudley ◽  
Hilary D. Mandler ◽  
Kenneth H. Mayer ◽  
Stephen H. Zinner

Serum inhibitory and bactericidal titers were measured in nine healthy volunteers following single iv doses of ciprofloxacin 100, 150, and 200 mg. The median peak serum bactericidal titer (5 minutes following completion of a 30-minute infusion) against two highly susceptible strains of Escherichia coli ranged between 1:64 and 1:1024 and titers exceeded 1:8 for six hours for all dose levels. The bactericidal titers against two strains of Pseudomonas aeruginosa and a methicillin-resistant strain of Staphylococcus aureus were considerably lower, the median peak being 1:2 at all dose levels. Measured inhibitory and bactericidal titers at five minutes and one hour postinfusion were significantly greater than those predicted (measured serum ciprofloxacin concentration to minimum inhibitory concentration [MIC] or minimum bactericidal concentration [MBC]) for only one strain of E. coli. Intravenous doses of ciprofloxacin 100–200 mg produce high and sustained serum bactericidal titers against highly susceptible bacteria; considerably lower levels of activity are seen against bacteria having higher MICs and MBCs but still considered susceptible to the drug.


Author(s):  
Enéas Costa Junior ◽  
Anderson Da Cunha Costa ◽  
Kivia Ludmilla Carvalho Ferreira ◽  
Kelly Maria Rêgo da Silva ◽  
Ester Miranda Pereira ◽  
...  

Objective: To evaluate the antimicrobial action of latex of Hancornia speciosa in two strains of bacteria causing Pneumonia. Method: The latex was collected and divided into two samples, a sample diluted in 5 mL of distilled water and dissolved in pure latex. The latex was then submitted to the Minimum Inhibitory Concentration (MIC) test, evaluating the lowest concentration capable of inhibiting the growth of strains of Staphylococcus aureus and Escherichia coli. Results: The Minimum Inhibitory Concentration test showed that the diluted latex had no antimicrobial effect in the Staphylococcus aureus strain and showed total inhibition of Escherichia coli growth. In the latex, in its pure form, showed growth in the first three dilutions tested and total inhibition in the others, behaving equally for both Staphylococcus aureus and Escherichia coli. Conclusion: Latex has antimicrobial action and low toxicity.


Author(s):  
Agus Purwanggana ◽  
Esti Mumpuni ◽  
Esti Mulatsari

Objective: The main objective of this research were screened in vitro and in silico of 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one as potential antibacterial agents.Methods: The in vitro antibacterial study was carried against Staphylococcus aureus, Staphylococcus epidermidis (gram positive) and Escherichia coli, Salmonella thypi (gram negative) using broth dilution method to determine Minimum Inhibitory Concentration (MIC), disc diffusion method to determine the diameter of inhibition zone. In silico antibacterial study was carried using computational software Protein-Ligand ANT System (PLANTS), computational docking was carried using receptor with Protein Data Bank (PDB) file 3MZD. The structures were optimized prior docking using YASARA, and MarvinSketch. The results of antibacterial testing were compared to two positive control drugs i. e amoxicillin and cefadroxil.Results: In vitro evaluation showed that 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has a better antibacterial activity than amoxicillin and cefadroxil with a Minimum Inhibitory Concentration (MIC) of 0.15 ppm and diameter of inhibition zone of 11.27±0.31, 11.35±0.39, 11.25±0.33, and 11.05±0.45 mm in Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Salmonella thypi, respectively. These results in line with in silico evaluation that showed 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has more negative docking score than amoxicillin, cefadroxil, and cloxacillin acyl as a native ligand on the 3MZD receptor.Conclusion: This results obtained in this research work were 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one compound potential as an antibacterial agent. 


2019 ◽  
Vol 807 ◽  
pp. 141-150
Author(s):  
Lin Yuan ◽  
Xue Ren Qian

Zeolite powders were first treated with hydrochloric acid, then reacted with sodium chloride, and sodium zeolite (Na-Zeolite) powders were obtained. Further Antibacterial zeolite powders were prepared by loading metal ions such as, Ag+ and Zn2+, Ag+ and Cu2+, Zn2+and Cu2+, Ag+ and Cu2+and Zn2+, through ion exchange. The powders were characterized by minimum Inhibitory concentration (MIC), SEM/EDXA and XRD. Antibacterial paper with antibacterial zeolite powders as filler was fabricated. The results demonstrated that MIC of loading (Ag++Zn2+) zeolite was 125ppm against Staphylococcus aureus and Escherichia coli . MIC of loading (Ag++Cu2++Zn2+) zeolite was 62.5ppm against Candida albicans and Aspergillus Niger. By adding 6% of (Ag++Zn2+), (Ag++Cu2+), and (Ag++Cu2++Zn2+) antibacterial zeolite powders, respectively, antibacterial paper were prepared; and the antibacterial rate of these papers against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus Niger for 4h is close to 100%.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Biswanath Chakraborty ◽  
Suchandra Chakraborty ◽  
Chandan Saha

The antibacterial activity of Murrayaquinone A (10), a naturally occurring carbazoloquinone alkaloid, and 6-methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione (11), a synthetic carbazoloquinone, both obtained during the development of the synthesis of Carbazomycin G, having unique quinone moiety, was studied against Gram-positive (Bacillus subtilisandStaphylococcus aureus) and Gram-negative (Escherichia coliandPseudomonassp.) bacteria. Compound10showed antibacterial activities against both ofEscherichia coliandStaphylococcus aureuswhereas compound11indicated the activity againstStaphylococcus aureusonly. Both compounds10and11exhibited minimum inhibitory concentration (MIC) of 50 μg mL−1againstStaphylococcus aureus.


Author(s):  
Ajirioghene A. Obroh ◽  
Ifeanyi O. Oshim ◽  
Oluwayemisi Odeyemi ◽  
Evelyn U. Urama ◽  
Nkechi A. Olise

Background: Moringa oleifera and Gongronema latifolium have many nutritional values that contain bioactive components such as alkaloids, saponin, tannin, steroids and terpenoids, as  antimicrobials.            Objective: The general purpose of this study was to evaluate the minimum inhibitory concentration (MIC) and Minimal bactericidal concentration(MBC) of both Moringa oleifera and Gongronema latifolium  extracts against Staphylococcus aureus, Salmonella typhi and Escherichia coli. Method: This is laboratory experimental research involving post test only control group design using the Kirby Bauer dilution method. With treatment combination of Moringa oleifera and Gongronema latifolium extracts concentration ranging from 50-200 mg/ml and positive control (gentamycin). Result: Mininum bacterial concentration was found between 6.25 mg /ml – 12.5mg /ml for Moringa oleifera and Gongronema latifolium extracts while minimum inhibitory concentration of Moringa oleifera and Gongronema latifolium was found between 12.5 mg / ml – 25.0 mg/ml respectively. U-Mann whitney results showed that the value of p < 0.05 were significant. In this study, the Staphylococcus aureus showed the highest inhibition zone diameter compared to other isolates. Conclusion: The results from this work affirms the use of Moringa oleifera and Gongronema latifolium as antimicrobials and emplores the attention of pharmaceutical companies to exploit production of antibiotics for treatment of infections resulting from Salmonella typhi and Staphylococcus aureus isolates.


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Hamidah ◽  
Salni ◽  
Nina Tanzerina

Escherichia coli is one of the bacteria that cause infections in the human digestive tract such as diarrhea, while Staphylococcus aureus is one of the bacteria that cause infections in the skin injury such as boils and pimples. This study used Syzygium zeylanicum leaves because it has potential as a antibacterial because it contains active compounds. This study aimed was determine the antibacterial activity of the fraction and the active compound in Syzygium zeylanicum leaves against Escherichia coli and Staphylococcus aureus. Research conducted on November 2015 to January 2016. The method used in this research were extraction by maceration, fractionation by liquid fractionation, antibacterial activity test, and determination of minimum inhibitory concentration with the diffusion method and isolation of active compounds by column chromatography method. The bacteria used in this test are Escherichia coli and Staphylococcus aureus. Data are presented in tabular form based on the average value of the inhibition diameter and deviation standard. The results of this research showed the water methanol active fraction against the bacteria that used in this test. The methanol water fraction had obtained one antibacterial compound in bottle 1,3,5 which shows the value of tannin Rf 0,416. The minimum inhibitory concentration of water methanol of water apple leaves is 1000 µg/mL for Escherichia coli and 500 µg/mL for  Staphylococcus aureus. The minimum  inhibitory concentration of the active  compound  to  Escherichia  coli  and  Staphylococcus  aureus  in  500  µg/mL.  The fraction and the active compound of water apple leaves have an antibacterial activity with Escherichia coli and Staphylococcus aureus and the active compound is tannin.


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