scholarly journals Antibacterial Activity and Acute Toxicity Testing of Biosynthesized Silver Nanoparticles against Methicilin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Ifeyomi Wilfred Olobayotan ◽  
Bukola Catherine Akin-Osanaiye ◽  
Olukemi A. Onuh

Antibacterial activity of biosynthesized silver nanoparticles was studied using the macrobroth dilution technique. The silver nanoparticles was significantly active (p > 0.05) against the test organisms at an extract concentration of 75 µg/ml. Concentrations ≤ 50 µg/ml were not as effective as the colony forming units at this concentration, 1.61 x 106 for methicillin-resistant Staphylococcus aureus and concentrations ≤ 25 µg/ml 1.45 x 106 for Pseudomonas aeruginosa respectively, were about the same range as the colony forming units of the controls. The silver nanoparticles inhibited Methicillin-Resistant S. aureus more (MIC of 75 µg/ml and MBC of 100 µg/ml) than they inhibited P. aeruginosa (both MIC and MBC was 100 µg/ml). The LD50 of the synthesized silver nanoparticles after oral administration was seen to be greater than 5000 mg/kg body weight and is therefore thought to be safe. This study supports the use of silver nanoparticles as therapeutic agents. KEYWORDS: Nanoparticles, Biosynthesis, Inhibition, Therapeutic agents, Macroboth Technique

2003 ◽  
Vol 47 (8) ◽  
pp. 2507-2512 ◽  
Author(s):  
Masakatsu Tsuji ◽  
Morio Takema ◽  
Hideaki Miwa ◽  
Jingoro Shimada ◽  
Shogo Kuwahara

ABSTRACT The in vivo antibacterial activity of S-3578, a new parental cephalosporin, was compared with those of cefepime, ceftriaxone, ceftazidime, imipenem-cilastatin, and vancomycin. The efficacy of S-3578 against systemic infections caused by methicillin-resistant Staphylococcus aureus (MRSA) SR3637 (50% effective dose [ED50], 7.21 mg/kg of body weight) was almost the same as that of vancomycin. In contrast, cefepime and imipenem-cilastatin were less active against this pathogen (ED50s, >100 and >100 mg/kg, respectively). S-3578 was the most effective compound against penicillin-resistant Streptococcus pneumoniae SR20946 (ED50, 1.98 mg/kg). S-3578 (10 mg/kg) induced a significant reduction in the numbers of viable MRSA SR17764 and Pseudomonas aeruginosa SR10396 organisms in polymicrobial pulmonary infections. The therapeutic efficacy of S-3578 was more potent than that of the combination of vancomycin and ceftazidime. High levels of S-3578 were detected in plasma in vivo, and its efficacy against experimentally induced infections in mice caused by MRSA and P. aeruginosa reflected its potent in vitro activity. We conclude that S-3578 is a promising new cephalosporin for the treatment of infections caused by gram-positive and -negative bacteria, including MRSA and P. aeruginosa.


Author(s):  
Faisal Yusuf Ashari ◽  
Setio Harsono ◽  
Manik Retno Wahyunitisari

Introduction: Infection of burn wound is a chronical disturbance to the skin, which is caused by Staphylococcus aureus and Pseudomonas aeruginosa, but lately many cases found that both bacteria have been resistant to the antibiotic. To overcome the infection caused by those bacteria, it is important to search for natural substance that has antibacterial activity to both bacteria. The power of natural substance is underestimated. Studies reveal that honey can be more effective for healing burns than modern medicine. The previous research revealed that amber honey and white honey were used as an alternative treatment against Pseudomonas aeruginosa Multi Resistant (PaMR) and Methicillin Resistant Staphylococcus aureus (MRSA). The aim of this study was to evaluate the antibacterial activity of amber honey and white honey on PaMR and MRSA.Methods: This research was conducted by performing antibacterial test phase, determining Minimum Inhibitory Concentration (MIC), and determining comparison value of antibacterial activity from amber honey and white honey to tetracycline.Results: The result of this research showed that both amber honey and white honey have antibacterial activity to both bacteria, by way of stronger antibacterial activity from white honey than amber honey. Amber honey and white honey have the same PaMR activity. MIC of white honey was 7.1% (to MRSA) and 12.3% (to PaMR), while MIC of amber honey was 10% (to MRSA) and 12.5% (to PaMR). The comparison value of antibacterial activity between amber honey and white honey to tetracycline for MRSA was equal to 1:1.08 x 10-4 and 1:1.62 x 10-4. The comparison value of antibacterial activity between amber honey and white honey to tetracycline for PaMR was equal to 1:5.62 x 10-6 and 1:1.03 x 10-5 .Conclusion: Amber honey and white honey have antibacterial activity against MRSA and PaMR. 


2020 ◽  
Vol 8 (3) ◽  
pp. 102-110
Author(s):  
Shailesh Budhathoki ◽  
Anima Shrestha

Actinomycetes are Gram positive, free living saprophytes which are distributed in soil as one of the major populations and are primary source of antibiotics. This study was carried out with a quest to isolate actinomycetes from soil samples of different places and assess their antibacterial activity. Isolation of actinomycetes was carried out by serial dilution of soil sample followed by spread plate method. The antimicrobial extract was extracted using ethyl acetate. Assessment of antimicrobial activity was performed by using Agar cup plate assay against test organisms (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Salmonella paratyphi, Bacillus subtilis, Staphylococcus aureus). Antibacterial activity was tested against Methicillin Sensitive Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus in the isolates having effective inhibitory activity against Staphylococcus aureus. From 15 soil samples of 12 different locations, 121 actinomycetes isolates were isolated. Among them, 58 (47.9%) isolates were inhibitory against at least 1 test organism in primary screening, of which 22 isolates effective against more than 1 test organism was chosen for secondary screening. Out of them, 8 were inhibitory against 2 test organisms while 14 were inhibitory against 3 test organisms. Staphylococcus aureus was found to be the most susceptible test organism with its susceptibility against 12 actinomycetes isolates. Among 12 isolates effective against Staphylococcus aureus, 10 were found to have an inhibitory effect against Methicillin Susceptible Staphylococcus aureus while 6 were found to have inhibitory effect against Methicillin Resistant Staphylococcus aureus strain. The findings of this study highlight the inhibitory potential of actinomycetes and the need for further investigation for obtaining novel antimicrobial agents from actinomycetes from various unexplored areas.


2021 ◽  
Author(s):  
Thu Ha Bui ◽  
Ngoc Dai Nghia Tran ◽  
Phung Anh Nguyen ◽  
Nhat Linh Duong ◽  
Van Minh Nguyen ◽  
...  

Abstract A cost-effective and green technique was performed for the synthesis of silver nanoparticles (AgNPs) from a plant resource using Citrus maxima peel (CMP) extract as a reducing agent. The formation of AgNPs was confirmed by UV-Vis Spectroscopy at the wavelength range of 400−500 nm. The optimized conditions for the AgNPs synthesis using CMP extract as a reducing agent were determined. At these conditions, the X-ray diffraction (XRD) and the high-resolution transmission electron microscopy (HRTEM) results revealed the face-centered cubic structure of AgNPs had a highly crystalline with the particle size in a range of 10−20 nm. The Fourier transform infrared spectroscopy (FT-IR) demonstrated the presence of flavonoid, terpenoid, phenolic, and glycosides in phytochemical compositions of CMP extract which can act as the reducing agents for AgNPs formation. The antibacterial effect of the AgNPs was evaluated against Methicillin-resistant Staphylococcus aureus (MRSA) by implementing the minimum inhibitory concentration (MIC), minimum batericidal concentration (MBC), and the zone of inhibition tests. The AgNPs exhibited effective antibacterial activity against bacteria with an average diameter of inhibition zones of 11.7 mm, the MIC of 8.27 µg/mL, and the MBC of the 16.54 µg/mL.


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