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An invitro study was conducted to investigate the antiviral properties of silver nanoparticles synthesized from fungal strain Aspergillus sps isolated from soil. The isolated and characterized silver nanoparticles exhibited as an excellent antiviral property on Bacteriophage viral strain. The viral inactivation process was increased with increasing the concentration of silver nanoparticles.
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Scholars Research Library
Der Pharmacia Lettre, 2012, 4 (2):649-651
ISSN 0975-5071
Scholar Research Library
Antiviral properties of silver nanoparticles synthesized by Aspergillus sps
G. Narasimha*
, Habeeb Khadri
and Mohammed Alzohairy
Department of Virology, Sri Venkateswara University, Tirupati, A.P, India
Department of Medical Sciences, College of Applied Medical Sciences, Qassim University,
Kingdom of Saudi Arabia
An invitro study was conducted to investigate the antiviral properties of silver nanoparticles synthesized from fungal
strain Aspergillus sps isolated from soil. The isolated and characterized silver nanoparticles exhibited as an
excellent antiviral property on Bacteriophage viral strain. The viral inactivation process was increased with
increasing the concentration of silver nanoparticles.
Key words: Aspergillus sps, Silver nanoparticls, E.coli, Bacteriophage, Antiviral activity.
In present days, resistance to commercially available antimicrobial agents by pathogenic microorganisms has been
increasing at an alarming rate and has become a serious problem. There is need to search for novel antimicrobial and
antiviral agents from natural and inorganic substances. The inorganic agent silver has been employed as most
antimicrobial agent, since ancient times to fight infections pathogens [1]The significant feature of silver is its broad
spectram antimicrobial property which is due to microbial colonization associated with biomaterial related
infections[2] . There are many invitro studies on antibacterial and antifungal properties of silver nanoparticles. But
the reports on antiviral activity of silver nanoparticles was scanty. Hence there is need for much research on antiviral
compounds including inorganic, organic and metallic nanoparticles from chemical and biological systems for
control of viral diseases in plants, animals, and human beings. In this study, an attempt was made on antiviral
properties of silver nanoparticles synthesized from soil fungi Aspergillus sps.
The viruses are obligative intracellular pathogenic agents in both eukaryotes and prokaryotes, the only real link
between viral bacteriophages and actual human pathogens, is their ability to alter the genome of non-virulent
bacteria strains, producing more virulent strains. Previous reports made on antiviral activity of chemical agents
iodine and chlorine dioxide against viral strains bacteriophag and poliovirus and concluded that oxidative damage of
sulfhydryl groups in the protein coat was an important aspect in the killing mechanism of nanoparticles [3].
Elechiguerra, (2005) [4]
reported that, silver nanoparticles with very small sizes are susceptible to Human Immuno
virus, binding of silver nanoparticles of size less than 5nm to gp120 protein of HIV virus prevented the virus from
attaching itself to the host tissue cells. The indications for use of a novel class of anti-HCV agent and exact antiviral
mechanism of metallic nanoparticles may lead to the development of agents with potent activities against viruses
G. Narasimha et al Der Pharmacia Lettre, 2012, 4 (2):649-651
Scholar Research Library
Collection of silver nanoparticles
The silver nanoparticles used in this study was synthesized from fungal strain Aspergillus their size and shapes were
reported [6]
Isolation of viral host (E.coli)
The viral host, bacterial strain (E.coli) was isolated from sewage water and the the culture was isolated on EMB
agar medium by streak plate method under sterile conditions. After incubation the agar plates were incubated in
incubator at 37
C . After incubation, the bacterial colonies with metallic shine (unique nature of E.coli) were
observed then transferred to nutrient broth and kept for shaking for preparing E.coli suspension. The viral host
E.coli, bacterial strains were cultured in TGYE medium with following chemical ingredients g/L (Tryptone; 10,
Glucose; 10, Yeast extract; 1, NaCl; 8. Typical viral phage preparations contain approximately 1X10
Enrichment of Bacteriophages
The bacteriophages were enriched by standard methods [7].
For this a known volume of sewage water was
transferred to conical flask; 5ml of 10X nutrient broth was transferred. This preparation was kept for mechanical
shaking for 5-6 hrs at room temperature.
Inactivation of virus with nanoparticles
The isolated viral strains in the sewage samples were treated with the silver nanoparticles with various
concentrations (30-240ppm) prepared and treated with virus particles in suspension and the mixture was vortexed
and incubated.
Plaques formation on medium
The bacteriophage viral suspension (treated and without treated nanoparticles) and the E.coli suspension were mixed
in soft agar medium and poured into replicative plates. After medium solidification is over the plates were incubated
at 37
C for 24 to 48 hrs in incubator. After incubation, the plates were observed for formation of plaques (Bacterial
cell lysis) and the number of plaques was counted.
The antiviral properties of silver nanoparticles isolated from soil fungi Aspergillus sps on bacteriphage was studied
and the results were reported in table.1. With increasing the nanoparticles concentration from 30-210 ppm the
veridical property also increased. It is an indication of decreasing the plaques number on the medium. Various
nanoparticle concentrations used in this study, the nanoparticles concentrations from 30-180ul range reduced the
plaque number, whereas at 210-240ppm totally inhibited the viral growth in host (bacteria)which is indication of
complete inhibition of viral replication (viral growth) in host.(table.1). Similarly an vitro studies have contributed to
the understanding of possible mechanisms by which nanoparticles or metal oxides such as Arsenic, Antimony leads
to induction of apoptosis, inhibition of growth and angiogenesis, modulation of cellular signaling pathways,
perturbation of cellular redox status, and promotion of differentiation[8].The two primary mechanisms control the
oxidant disinfection efficiency by hydroxyl radicals: [9] oxidation and disruption of the cell wall and membrane
with resulting disintegration of the cell [10].The diffusion of antiviral agent into the cell where it may inactivate
the enzymes, damage intracellular components, interfere with protein synthesis and DNA replication[11]. The lower
surface to volume ratio of the viruses may provide greater rates of hydroxyl radical reaction with intracellular
biological molecules compared with the larger bacterial cells. The relatively slow diffusion of hydroxyl radicals into
viruses, and particularly bacterial cells, may be the cause of its low disinfection rate, and may limit its use as a
disinfectant [12] The antiviral activity in the present study correlates with antimicrobial activity of silver
nanoparticles from Aspergillus niger jaydev and Narasimha ( 2010) [13] and white button mushrooms (Agaricus
bisporus) Narasimha et al ( 2011) [14].
Elechiguerra et al (2005) [4] reported that
the silver nanoparticles with very
small size are susceptible to bacteria and fungi and HIV, binding of silver nanoparticles of size equal /less than 5nm
to gp 120 protein of HIV virus prevented the virus from attaching itself to the host tissue cells. Further research
needs to be in-depth of work on antiviral properties of silver nanoparticles and their molecularchr mechanism on
viral inhibition.
G. Narasimha et al Der Pharmacia Lettre, 2012, 4 (2):649-651
Scholar Research Library
Table.1.Ant viral properties silver nanoparticles at various concentrations
Plate No Silvernanoparticle suspension (in ppm) No. of Plaques*
1 Without silvernanoparticles (Control) 120
2 30 72
3 60 54
4 90 34
5 120 18
6 150 9
7 180 2
8 210 ND
9 240 ND
*Values represented in the table are mean of duplicates
Pfu plaque forming units
ND: Not detected
Silver nanoparticles synthesized from soil fungi, Aspergillus sps effectively inhibited the growth of Bacteriophage
virus in host bacteria. The viral inactivation process was increased with increasing the concentration of nanoparticle
is an indication of antiviral properties of silver nanopartilces.
[1] M.Bellantone, N.L.Coleman, J.B.Hench. J.T. Kouri, J.M. Ramiraj Yacama, Nanobiotechnol,; 2005 16, 23-46
[2] A.G Gristina, Science,; 1987 237, 1588
[3] G. M. Byrion, Water Res,; 1999 33, 169–179
[4]J.L. Elechiguerra, J.R.Burt, A.Morones,. Gao .ChamachoBragado, H.H Lara,, M.J Yacaman J.Nanobiotechnol,;
[5] J.Nanobiotechnol, P.Roger, B. C. Johnson Robert, M. Andrew, Kropinski, J.Erika Lingohr, L. Carlton Gyles,
N,Jamalludeen, Vet. Microbiol,; 2 007 124 :47– 57
[6] K.S.H.Naveen, K.V.BhaskaraRao , G.kumar, Karthic , G.Narasimha, Biotechnol,;2011 5 (4):, 29-36
[7] N. Beaudoin, Danielle R DeCesaro, Debrah LDurkee, and Susan E Barbaro, 2007, Rivier Academic Journal,
Volume 3, Number 1, Spring.
[8] W.H. Miller, H.M. Schipper, J.S. Lee. J Singer, S .Waxman, Cancer Res,; 2002 62, 3893–3903
[9] J.R. Bolton, K.G.Linden, J. Environ. Eng ,; 2003 129, 209–221
[10] J.H. Baxendale, J.A Wilson, Trans. Faraday Soc,; 1957 53, 344–356.
[11] J.M. Montgomery, 1985 Water Treatment Principles and Design, John Wiley, New York, 1985.
[12] R.J. Watt., M.P. Kong, O.C.M.Glenn, B.H.Henry, Water Res,; 1995 29, 95–100.
[13] L.R .Jaydev, G. Narasimha, Coll. Surf, B.Biointerfaces,; 2010 81, 830-833
[14] G. Narasimha, B. Praveen, Mallikarjuna and B. Deva prasad Raju, Int. J. Nano.dim,; 2011 2 (1): 29-36
... Furthermore, antiviral activity of biosynthesized NPs from bacteria and fungus has been shown in only a few cases. AgNPs produced from Aspergillus sp. were found to have antiviral efficacy against a bacteriophage virus strain by Narasimha et al. (2012). AgNPs produced from the fungus strain A. niger at 8-12 ppm completely suppressed viral development in the host bacterial strain E. coli, according to Narasimha et al. (2012). ...
... AgNPs produced from Aspergillus sp. were found to have antiviral efficacy against a bacteriophage virus strain by Narasimha et al. (2012). AgNPs produced from the fungus strain A. niger at 8-12 ppm completely suppressed viral development in the host bacterial strain E. coli, according to Narasimha et al. (2012). Gaikwad et al. (2013) discovered that AgNPs can protect against herpes simplex virus and human parainfluenza virus type 3 by synthesizing them. ...
Several microorganisms might be used in the production of nanoparticles. Endophytic fungi have received considerable interest in recent years for the manufacture of metallic nanoparticles due to their metal tolerance, metal absorption, and accumulation capabilities. In compared to other microorganisms, fungi are good machinery for the synthesis of any type of metallic nanoparticle, and can provide a number of advantages, including I easy isolation from soil or plants, as opposed to rare bacteria and actinomycetes, which require particular enrichment techniques. (ii) Secrete a large number of metabolites and extracellular enzymes that aid in the reduction of metal ions into nanoparticles. (iii) Because of their quick growth, they are simple to scale-up (iv). Because most fungi grow in a wide range of pH, temperature, and NaCl concentrations, it is easy to change culture conditions and produce consistent nanoparticles. The production of metal nanoparticles from entophytic fungi and their possible biological applications are the subject of this chapter.
... The AgNPs from fungi were observed to inhibit various types of viruses in a concentration-dependent manner. Researchers showed that the AgNPs from the fungi of Aspergillus group have the ability to inhibit the growth of bacteriophage at a concentration of 30-21 pp, causing a reduction in the number of plaques (Narasimha et al., 2012). It was also observed that nanoparticle produced from Aspergillus sp. ...
... showed inhibition of viral bacteriophage from 80 to 32 PFU, whereas the control showed a value of 78 PFU (Vijayakumar and Prasad, 2009). The dimension of AgNPs produced from the A. niger showed high efficacy as an antiviral agent by preventing the proliferation of the bacteriophage within the host E. coli cells (Narasimha et al., 2012). Studies have also shown that AgNPs obtained from F. oxysporum and Curvularia sp. ...
Silver nanoparticles (AgNPs) are among the various types of the metallic nanoparticles considered to possess antimicrobial potential. The use of biogenic sources as a potential reducing agent for synthesis nanoparticle is promptly increasing in comparison to physical and chemical methods. Amongst the biogenic sources, fungi are more preferred microorganisms to use for AgNPs synthesis as they are easy to culture and can control the size and morphology of the synthesized nanoparticles and help in low-cost large-scale production. The use of fungi for AgNPs synthesis is a rapid, environmentally safe, and cost-effective approach for vector control strategies in the future. Fungi can act as an effective agent in comparison to other microorganisms as it has the ability of producing higher amount of enzymes and proteins with the potential for synthesizing nanoparticles. Fungi-mediated synthesized nanoparticles possess coatings of biomolecules, which increases their activity. Organisms like Aspergillus flavus, Rhizopus sp., and Fusarium oxysporum were reported to possess extracellular material or biomass, which helps in the reduction of silver ions to AgNPs. This chapter focusses solely on fungi-mediated AgNPs synthesis, with their preferred physico-chemical parameters, their mode of action, and their applications in various modern aspects.
... A. fumigatus-reduced AgNPs showed antiviral activity against HIV-1. Narasimha et al. [165] showed antiviral properties of Aspergillus sp. reduced AgNPs by inhibiting viral particles in bacterial host cells, reduction in number of viral plaques, and complete inactivation of viral replication. ...
The fabrication of nanomaterials with controlled sizes, shapes, and geometries is considered the most crucial part of nanotechnology. During past years, the global economic metier of nanomaterials has primed up at an annual growth rate compounded at >20%. One of the major challenges posed in the expansive advancement of nanomaterials is the “concern and alarm call” for ecological sustainability of nanosynthetic processes. Traditionally, top-down or bottom-up approaches of physical and chemical protocols are characterized by low process yield, usage of reactive reactants of acidic/basic moieties and organic solvents,generation of deleterious end products, and the requirements of specific operative conditions and high purity levels of starting reactants. In this context, the principles of green chemistry (commencing from invention, design, and application of chemical procedures to reduction/elimination of usage and generation of dangerous substances) amalgamated with microbial technology (usage of living cells: bacteria, fungi, microalgae, plants, and enzymes) offer a striking assortment of scientific interfacein the advances of more sustainable processes.
... This may be due to the silver nanoparticles inability to activate the plants' induced systemic resistance against CMV infection. Silver nanoparticles may affect the RNA copying during viral multiplication and it is clear that silver nanoparticles significantly influence the inhibition of viral nucleic acid replication when silver nanoparticle particles become less than the size of the particles [36,37]. ...
... Aspergillus spp. synthesized AgNPs have been observed to show noteworthy antiviral activity against bacteriophages [126][127][128]. ...
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The antiviral property of silver nanoparticles synthesized fromfungal strain Aspergillus niger was tested in this study. The characterized silver nanoparticles with small size (3-10nm) showed an excellent antiviral agent. The viral inactivation process was increased with increasing the concentration. The colloidal silver nanoparticle at 8-12ppm totally inhibited the viral growth in host bacterial strain, E.coli.
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In this paper we report an eco-friendly route for the synthesis of sliver nanoparticles using Agaricus bisporus (white button mushroom) extract. The synthesized silver nanoparticles were confirmed and characterized by UV-Visible spectrum of the aqueous solution containing silver ions showed a peak at 420 nm corresponding to the surface plasmon absorbance of silver nanoparticles. Transmission Electron Microscopy (TEM) micrographs showed the size of silver nanoparticles and were measured in the range of 8-50nm, Fourier Transform Infrared Spectroscopy (FTIR) spectrum detection of analysis showed peaks between 500-4000 cm-1 confirmed the presence of proteins, carbonyl groups, esters and carboxylic acids for the synthesis and stabilization of silver nanoparticles .X-ray diffraction (XRD) spectrum of the silver nanoparticles exhibited 2θ values corresponding to the silver nanocrystal. Further, the antibacterial activity of synthesized silver nanoparticles showed effective inhibitory activity against pathogens and non- pathogenic bacterial strains vis, Escherichia coli, Staphylococcus sps, pseudomonas sps, and Bacillus sps
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MS2 coliphage Viruses suspended in buffered distilled water were rapidly inactivated by < 5 mg/L iodine doses, losing 6 logs (99.9999%) of infectivity within less than 3 min contact time. The effect of pH on MS2 inactivation within the range of 6 to 8 was not statistically significant. However, in the presence of dissolved organic substances, such as detergents and proteins, the inactivation of MS2 viruses decreased significantly to less than 4 logs (99.99%). Of special interest was that in the presence of beef extract proteins, an apparent reversal of MS2 inactivation, dubbed rebound, was observed. It was observed that after an initial 5 to 6 log reduction in infectivity, a consistent and-statistically significant increase in the number of plaque forming units (PFU), as much as 2 logs, was measured. MS2 rebound occurred only when the oxidized iodine residual had been quickly consumed by beef extract proteins in solution. Neither virus particle aggregation nor water salinity were found to account for the increase in PFU values. Based on other investigators' suggestions that iodine disinfection caused changes to viral protein-coats, it was hypothesized that conformational changes in MS2's protein coat caused by iodine would result in a change in the isoelectric focusing point of whole MS2 virions. A shift in isoelectric focusing point from an acidic pH Value of 3.9 to more basic values, and a dispersion of the virus band after exposure to high levels of iodine was observed, supporting the hypothesis that iodine caused changes in the charge distribution characteristics of the protein coat.
  • G M Byrion
G. M. Byrion, Water Res,; 1999 33, 169-179
  • M Bellantone
  • N L Coleman
  • J B J T Hench
  • J M Kouri
  • Ramiraj Yacama
M.Bellantone, N.L.Coleman, J.B.Hench. J.T. Kouri, J.M. Ramiraj Yacama, Nanobiotechnol,; 2005 16, 23-46
  • R J Watt
  • M P Kong
  • O C M Glenn
  • B H Henry
R.J. Watt., M.P. Kong, O.C.M.Glenn, B.H.Henry, Water Res,; 1995 29, 95-100.
  • J L Elechiguerra
  • J R Burt
  • A Morones
  • Gao
  • H Chamachobragado
  • M Lara
J.L. Elechiguerra, J.R.Burt, A.Morones,. Gao.ChamachoBragado, H.H Lara,, M.J Yacaman J.Nanobiotechnol,; 2005
  • K S H Naveen
  • K V Bhaskararao
  • G Kumar
  • G Karthic
  • Narasimha
K.S.H.Naveen, K.V.BhaskaraRao, G.kumar, Karthic, G.Narasimha, Biotechnol,;2011 5 (4):, 29-36
  • N Beaudoin
  • Danielle R Decesaro
  • Debrah Ldurkee
  • E Susan
  • Barbaro
N. Beaudoin, Danielle R DeCesaro, Debrah LDurkee, and Susan E Barbaro, 2007, Rivier Academic Journal, Volume 3, Number 1, Spring.