Antibacterial, anti-biofilm activity and mechanism of action of pancreatin doped zinc oxide nanoparticles against methicillin resistant Staphylococcus aureus

Abstract Background Herein, we first time used the gum Moringa oleifera as reducing and capping agent for successful synthesis of silver nitrate and zinc oxide nanoparticles(NPs) through green synthesis approach. This study was aimed to check antibacterial activities of synthesized NPs against multidrug resistant bacteria methicillin-resistant Staphylococcus aureus (MRSA). Methods Aqueous solutions of AgNO3 and purified gum powder were mixed with 1:1 ratio, autoclaved at 120oC for 2 min. NPs pellet collected after centrifugation at 10,000 g for 20 min. ZnO NPs were prepared by mixing purified gum powder and metal salt with1:1 ratio, heated (70oC) and stirred at 100 rpm for 4 h followed by centrifugation at 10,000 g for 20 min. Pellet was washed and calcinated at 400oC for 4 h. Antibacterial potential against E. coli, S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) was assessed by widely used Kirby-Bauer antibiotic susceptibility test. Results Optical observation of colour change from transparent to dark and UV-Visible analysis confirmed the synthesis of NPs. Fourier transform infrared spectroscopy (FTIR) of prepared nonmaterial revealed the characteristic AgNPs and ZnO stretch vibrations at wave number of 523 cm− 1 and 471 cm− 1resectively. Crystalline nature of AgNPs and ZnO NPs was confirmed by x-ray diffraction pattern with clear sharp Peaks. Scanning electron microscopy (SEM) revealed good surface morphology of AgNPs and ZnO NPs with 50nm and 60nm size respectively. AgNPs and ZnO NPs exhibited excellent antibacterial activity against E. coli (with zone of inhibition of 21 ± 02mm and 22 ± 03mm) and S.aureus ( with zone of inhibition of 20 ± 03mm and 21 ± 02mm) while good activity was observed against “super bug” methicillin-resistant Staphylococcus aureus (MRSA) with 16 ± 03mm ad 17 ± 02mm zone if inhibitions respectively. Conclusions This novel addition of Moringa Gum based nanoparticles will open new dimensions in the field of nanomedicine and pharmaceutics especially against MDR bacterial strains.

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A Molecular Insight into the Synergistic Mechanism of Nigella sativa (Black Cumin) with β-Lactam Antibiotics against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Applied Sciences ◽

10.3390/app11073206 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3206

Author(s):

Lorina I. Badger-Emeka ◽

Promise Madu Emeka ◽

Hairul Islam M. Ibrahim

Keyword(s):

Staphylococcus Aureus ◽

Mechanism Of Action ◽

Methicillin Resistant Staphylococcus Aureus ◽

Nigella Sativa ◽

Synergistic Effects ◽

Diffusion Method ◽

Methicillin Resistant ◽

Cell Wall Disruption ◽

Time Kill ◽

Insight Into

Methicillin-resistant Staphylococcus aureus (MRSA) infection is detrimental to hospitalized patients. With diminishing choices of antibiotics and the worry about resistance to colistin in synergistic combined therapy, there are suggestions for the use of herbal derivatives. This investigation evaluated the synergistic effects of Nigella sativa (NS) in combination with beta-lactam (β-lactam) antibiotics on extreme drug-resistant (XDR) MRSA isolates. NS concentrations of 10, 7.5, 5.0, 2.5, 1.0, and 0.1 µg/mL, alone and in combination with β-lactam antibiotics, were used to determine the antimicrobial susceptibility of MRSA isolates by the well diffusion method. Time–kill assays were performed using a spectrophotometer, with time–kill curves plotted and synergism ascertained by the fractional inhibitory concentration (FIC). Scanning and transmission electron microscopy were used to gain insight into the mechanism of action of treated groups. Isolates were inhibited by the NS concentrations, with differences in the zones of inhibition being statistically insignificant at p < 0.05. There were statistically significant differences in the time–kill assay for the MRSA isolates. In addition, NS combined with augmentin showed better killing than oxacillin and cefuroxime. The mechanism of action shown by the SEM and TEM results revealed cell wall disruption, which probably created interference that led to bacterial lysis.

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Synthesis of zinc oxide and silver nanoparticles using ficus palmata - Forssk leaf extracts and assessment of antibacterial activity

Environmental Engineering Research ◽

10.4491/eer.2020.454 ◽

2020 ◽

Vol 26 (6) ◽

pp. 200454-0

Author(s):

Sabaoon Shamshad ◽

Jamshaid Rashid ◽

Ihsan-ul-haq ◽

Naseem Iqbal ◽

Saif Ullah Awan

Keyword(s):

Staphylococcus Aureus ◽

Silver Nanoparticles ◽

Zinc Oxide ◽

Antibacterial Activity ◽

Zinc Oxide Nanoparticles ◽

Inhibitory Concentration ◽

Oxide Nanoparticles ◽

Leaf Extracts ◽

E Coli ◽

Ficus Palmata

Multidrug resistance of bacteria is an emerging human health hazard and warrants development of novel antibacterial agents with more effective mode of action. Here, zinc oxide and silver nanomaterials were prepared using Ficus palmata Forssk leaf extract with efficient antibacterial activity. SEM coupled with EDS confirmed the spherical symmetry with average particle diameter 50 to 65 nm while the XRD confirmed crystalline face centered cubic structure of silver and hexagonal crystallize phase of zinc oxide nanoparticles. Antibacterial activity was evaluated for 8 pathogenic bacterial strains including 3 drug resistant pathogenic strains. The nanoparticles showed enhanced growth inhibition for resistant strains in comparison with the broad-spectrum antibiotics i.e. roxithromycin and cefixime. Minimum inhibitory concentration in μg.mL-1 of silver nanoparticles was found to be as low as 33.3 for resistant Streptococcus haemolyticus; 11.1 for Staphylococcus aureus and E Coli; and 3.7 μg.mL-1 for resistant Pseudomonas aeruginosa. Similarly, the minimum inhibitory concentration of zinc oxide nanoparticles was found to be 100 μg.mL-1 against resistant Streptococcus haemolyticus and Staphylococcus aureus; 11.1 μg.mL-1 for resistant Pseudomonas aeruginosa; and 3.7 μg.mL-1 against resistant E coli. Ficus palmata Forssk leaf extracts can be explored effectively for synthesizing active antibacterial nanomaterials as a non-toxic and environmentally benign synthesis route.

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