Journal of Medical Bacteriology 2018. 7(1-2):36-43.

Synergistic Effect between Phyto-Syntesized Silver Nanoparticles and Ciprofloxacin Antibiotic on some Pathogenic Bacterial Strains
Yaser Nikparast, Mahsa Saliani


Background:    Plant extract as a potential phyto-reducer is used as a simple, non-toxic and ecofriendly green synthesis method of silver nanoparticles (AgNPs). In this study biosynthesis of AgNPs using leaves extract broth of Amaranthus retroflexus as both reducing and stabilizing agent was analyzed. Antibacterial activity toward resistant human pathogenic bacteria Escherichia coli and Pseudomonas aeruginosa and also against plant pathogenic bacteria Pseudomonas syringae, Xanthomonas oryzae, was studied. The biosynthesized AgNPs were also evaluated for their increased antimicrobial activities with Ciprofloxacin antibiotic against some of the tested bacteria.

Methods:   The formation of green synthesized nanoparticles from aqueous solution of silver nitrate was first screened by measuring the surface plasmon resonance peak at 300-800 nm using UV–vis spectroscopy. The morphology, size and Crystalline structure of the synthesized AgNPs was determined using Transmission Electron Microscope (TEM), DLS and X-ray diffraction analysis. For antibacterial studies two-fold serial dilutions were made in NB medium (Qlab Canada) and the growth of the cultures was monitored by measuring the optical density value at 630 nm (OD630) with microplate reader (Biotech ELX 800) after 24 hours of incubation to obtain the MIC of the AgNPs.

Results:     The results indicated that the phyto-synthesized AgNPs were spherical with an average size of 48 nm. XRD peaks indicate the presence of a face centered cubic (fcc) structure of crystalline AgNPs.  The AgNPs showed highly potent antibacterial activity toward the tested bacteria. Also the combined antibacterial activity of Ciprofloxacin with AgNPs reduced the MIC of antibiotic from 0.125 µg/ml to 0.0625 µg/ml toward P. aeruginosa and Ciprofloxacin MIC against P. syringae decreased from 0.25 to 0.0625 µg/ml in combination with 6.25, 12.5, and 25 µg/ml of AgNPs.

Conclusion:     Results from the current study suggested that the silver nanoparticles successfully can be synthesized using Amaranth leaf extract. The phyto-synthesized nanoparticles could have potential antibacterial applications and show synergistic effect in combination with Ciprofloxacin antibiotic.


Antibacterial activity, Biosynthesis, Optimization, Plant extract, Silver nanoparticles.

Full Text:



Ghorbani HR, Safekordi AA, Attar H, et al. Biological and non-biological methods for silver nanoparticles synthesis. Chemical and Biochemical Engineering Quarterly, 2011; 25(3):317-326.

Mittal AK, Bhaumik J, Kumar S, Banerjee UC. Biosynthesis of silver nanoparticles: Elucidation of prospective mechanism and therapeutic potential. J Colloid Interface Sci 2014a; 415:39-47.

Roopan SM, Rohit, Madhumitha G, et al. Low-cost and eco-friendly phyto-synthesis of silver nanoparticles using Cocos nucifera coir extract and its larvicidal activity. Ind Crops Prod 2013; 43:631-5.

Mittal J, Batra A, Singh A, Sharma MM. Phytofabrication of nanoparticles through plant as nanofactories. Adv Nat Sci Nanosci Nanotechnol 2014b; 5:43002.

Durán N, Marcato PD, Durán M, et al. Mechanistic aspects in the biogenic synthesis of extracellular metal nanoparticles by peptides, bacteria, fungi, and plants. Appl Microbiol Biotechnol 2011; 90:1609-24.

Azócar MI, Tamayo L, Vejar N, et al. A systematic study of antibacterial silver nanoparticles: Efficiency, enhanced permeability, and cytotoxic effects. J Nanoparticle Res 2014; 16.

Rai M, Yadav A, Gade A. Silver nanoparticles as a new generation of antimicrobials. Biotechnol Adv 2009; 27:76-83.

Vijayakumar M, Priya K, Nancy FT, et al (2013) Biosynthesis, characterisation and anti-bacterial effect of plant-mediated silver nanoparticles using Artemisia nilagirica. Ind Crops Prod 41:235-40.

Das S, Das J, Samadder A, et al. Biosynthesized silver nanoparticles by ethanolic extracts of Phytolacca decandra, Gelsemium sempervirens, Hydrastis canadensis and Thuja occidentalis induce differential cytotoxicity through G2/M arrest in A375 cells. Colloids Surfaces B Biointerfaces 2013; 101:325-36.

Logeswari P, Silambarasan S, Abraham J (2013) Ecofriendly synthesis of silver nanoparticles from commercially available plant powders and their antibacterial properties. Sci Iran 20:1049-54.

Zarei, M., Jamnejad, A. and Khajehali, E., 2014. Antibacterial effect of silver nanoparticles against four foodborne pathogens. Jundi J Microbiol 7(1).

Jyoti K, Baunthiyal M, Singh A. Characterization of silver nanoparticles synthesized using Urtica dioica Linn. leaves and their synergistic effects with antibiotics. J Radiat Res Appl Sci 2016; 9:217-27.

Saxena A, Tripathi RM, Zafar F, et al. Green synthesis of silver nanoparticles using aqueous solution of Ficus benghalensis leaf extract and characterization of their antibacterial activity. Mater Lett 2012; 67:91-94.

Ramesh PS, Kokila T, Geetha D. Plant mediated green synthesis and antibacterial activity of silver nanoparticles using Emblica officinalis fruit extract. Spectrochim Acta Part A Mol Biomol Spectrosc 2015; 142:339-43.

Guzman M, Dille J, Godet S. Synthesis and antibacterial activity of silver nanoparticles against gram-positive and gram-negative bacteria. Nanomedicine Nanotechnology, Biol. Med 2012; 8:37-45

Durán N, Durán M, de Jesus MB, et al (2016) Silver nanoparticles: A new view on mechanistic aspects on antimicrobial activity. Nanomedicine Nanotechnology, Biol Med 12:789-99.

Sondi I, Salopek-Sondi B. Silver nanoparticles as antimicrobial agent: A case study on E. coli as a model for Gram-negative bacteria. J Colloid Interface Sci 2004; 275:177-82.

Franci, G., Falanga, A., Galdiero, S., Palomba, L., Rai, M., Morelli, G. and Galdiero, M. Silver nanoparticles as potential antibacterial agents. Molecules, 2015; 20(5): 8856-74.

LeBel M. Ciprofloxacin: Chemistry, Mechanism of Action, Resistance, Antimicrobial Spectrum, Pharmacokinetics, Clinical Trials, and Adverse Reactions. Pharmacother J Hum Pharmacol Drug Ther 1988; 8:3-30.


  • There are currently no refbacks.

Creative Commons Attribution-NonCommercial 3.0

This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License which allows users to read, copy, distribute and make derivative works for non-commercial purposes from the material, as long as the author of the original work is cited properly.