Antibacterial effects of microbial synthesized silver-copper nanoalloys on Escherichia coli, Burkholderia cepacia, Listeria monocytogenes and Brucella abortus

  • Sheida Mohammadi Students´ Research Committee, Urmia University of Medical Sciences, Urmia, Iran
  • Nima Hosseini Jazani Department of Microbiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
  • Mehri Kouhkan Faculty of Pharmacology, Urmia University of Medical Sciences, Urmia, Iran
  • Leila Ashrafi Babaganjeh Faculty of Pharmacology, Urmia University of Medical Sciences, Urmia, Iran
Keywords: Escherichia coli, Burkholderia cepacia, Listeria monocytogenes, Brucella abortus, Ag-Cu nanoalloy


Background and Objectives: Bacterial resistance is an emerging public health problem worldwide. Metallic nanoparticles and nanoalloys open a promising field due to their excellent antimicrobial effects. The aim of the present study was to investigate the antibacterial effects of Ag-Cu nanoalloys, which were biosynthesized by Lactobacillus casei ATCC 39392, on some of the important bacterial pathogens, including Escherichia coli, Burkholderia cepacia, Listeria monocytogenes and Brucella abortus. Materials and Methods: Ag-Cu nanoalloys were synthesized through the microbial reduction of AgNO3 and CuSO4 by Lactobacillus casei ATCC39392. Furthermore, they were characterized by Fourier-Transform Infrared Spectrometer (FTIR) and Field Emission Scanning Electron Microscopy (FESEM) analysis in order to investigate their chemical composition and morphological features, respectively. The minimum inhibitory and minimum bactericidal concentrations of Ag-Cu nanoalloys were determined against each strain. The bactericidal test was conducted on the surface of MHA supplemented with 1, 0.1, and 0.01 μg/µL of the synthesized nanoalloy. The antimicrobial effects of synthesized nanoalloy were compared with ciprofloxacin, ampicillin and ceftazidime as positive controls. Results: Presence of different chemical functional groups, including N-H, C-H, C-N and C-O on the surface of Ag-Cu nanoalloys was recorded by FTIR. FESEM micrographs revealed uniformly distributed nanoparticles with spherical shape and size ranging from 50 to 100 nm. The synthesized Ag-Cu nanoalloys showed antibacterial activity against L. monocytogenes PTCC 1298, E. coli ATCC 25922 and B. abortus vaccine strain. However, no antibacterial effects were observed against B. cepacia ATCC 25416. Conclusion: According to the findings of the present research, the microbially synthesized Ag-Cu nanoalloy demonstrated antibacterial effects on the majority of the bacteria studied even at 0.01 μg/µL. However, complementary investigations should be conducted into the safety of this nanoalloy for in vivo or systemic use.


Iravani S, Korbekandi H, Mirmohammadi SV, Zolfaghari B. Synthesis of silver nanoparticles: chemical, physical and biological methods. Res Pharm Sci 2014; 9:385-406.

Chernousova S, Epple M. Silver as antibacterial agent: ion, nanoparticle, and metal. Angew Chem Int Ed Engl 2013; 52:1636-1653.

Zhang X-F, Liu Z-G, Shen W, Gurunathan S. Silver nanoparticles: Synthesis, characterization, properties, applications, and therapeutic approaches. Int J Mol Sci 2016; 17:E1534.

Chatterjee AK, Chakraborty R, Basu T. Mechanism of antibacterial activity of copper nanoparticles. Nanotechnology 2014; 25:135101.

Tamayo L, Azocar M, Kogan M, Riveros A, Paez M. Copper-polymer nanocomposites: An excellent and cost-effective biocide for use on antibacterial surfaces. Mater Sci Eng C Mater Biol Appl 2016; 69:1391-1409.

Tiwari M, Narayanan K, Thakar MB, Jagani HV, Venkata Rao J. Biosynthesis and wound healing activity of copper nanoparticles. IET Nanobiotechnol 2014; 8:230-237.

Ren G, Hu D, Cheng EW, Vargas-Reus MA, Reip P, Allaker RP. Characterisation of copper oxide nanoparticles for antimicrobial applications. Int J Antimicrob Agents 2009; 33:587-590.

Shah M, Fawcett D, Sharma S, Tripathy SK, Poinern GEJ. Green synthesis of metallic nanoparticles via biological entities. Materials (Basel) 2015; 8:7278-7308.

Sathishkumar M, Sneha K, Won S, Cho C-W, Kim S, Yun Y-S. Cinnamon zeylanicum bark extract and powder mediated green synthesis of nano-crystalline silver particles and its bactericidal activity. Colloids Surf B Biointerfaces 2009; 73: 332-338.

Kuppusamy P, Yusoff MM, Maniam GP, Govindan N. Biosynthesis of metallic nanoparticles using plant derivatives and their new avenues in pharmacological applications–An updated report. Saudi Pharm J 2016; 24: 473-484.

Jain D, Daima HK, Kachhwaha S, Kothari S. Synthesis of plant-mediated silver nanoparticles using papaya fruit extract and evaluation of their anti microbial activities. Dig J Nanomater Biostruct 2009; 4:557-563.

Singh A, Jain D, Upadhyay M, Khandelwal N, Verma H. Green synthesis of silver nanoparticles using Argemone mexicana leaf extract and evaluation of their antimicrobial activities. Dig J Nanomater Biostruct 2010; 5:483-489.

Vijayakumar M, Priya K, Nancy F, Noorlidah A, Ahmed A. Biosynthesis, characterisation and anti-bacterial effect of plant-mediated silver nanoparticles using Artemisia nilagirica. Ind Crops Prod 2013; 41:235-240.

Gan PP, Ng SH, Huang Y, Li SFY. Green synthesis of gold nanoparticles using palm oil mill effluent (POME): a low-cost and eco-friendly viable approach. Bioresour Technol 2012; 113:132-135.

Iravani S. Green synthesis of metal nanoparticles using plants. Green Chem 2011; 13:2638-2650.

Ingle A, Rai M, Gade A, Bawaskar M. Fusarium solani: a novel biological agent for the extracellular synthesis of silver nanoparticles. J Nanopart Res 2009; 11:2079-2085.

Pantidos N, Horsfall LE. Biological synthesis of metallic nanoparticles by bacteria, fungi and plants. J Nanomed Nanotechnol 2014; 5:233.

Alvarez-Puebla RA, Bravo-Vasquez JP, Cheben P, Xu D-X, Waldron P, Fenniri H. SERS-active Ag/Au bimetallic nanoalloys on Si/SiO(x). J Colloid Interface Sci 2009; 333:237-241.

Sopousek J, Pinkas J, Broz P, Bursik J, Vykoukal V, Skoda D, et al. Ag-Cu colloid synthesis: bimetallic nanoparticle characterization and thermal treatment. J Nanomater 2014; Article ID 638964.

Taner M, Sayar N, Yulug IG, Suzer S. Synthesis, characterization and antibacterial investigation of silver–copper nanoalloys. J Mater Chem 2011; 21:13150-13154.

Rocha-Rocha O, Cortez-Valadez M, Hernandez-Martinez AR, Gamez-Corrales R, Alvarez R, Britto-Hurtado R, et al. Green synthesis of Ag-Cu nanoalloys using Opuntia ficus-indica. J Electron Mater 2017; 46:802-807.

Allocati N, Masulli M, Alexeyev MF, Di Ilio C. Escherichia coli in Europe: an overview. Int J Environ Res Public Health 2013; 10:6235-6254.

Vazquez-Boland JA, Kuhn M, Berche P, Chakraborty T, Dominguez-Bernal G, Goebel W, et al. Listeria pathogenesis and molecular virulence determinants. Clin Microbiol Rev 2001; 14:584-640.

Khan SH, Badovinac VP. Listeria monocytogenes: a model pathogen to study antigen-specific memory CD8 T cell responses. Semin Immunopathol 2015; 37:301-310.

Yan SF, Wang W, Bai L, Hu YJ, Dong YP, Xu J, et al. Antimicrobial resistance, virulence profile, and molecular characterization of Listeria monocytogenes isolated from ready-to-eat food in China, 2013-2014. Biomed Environ Sci 2016; 29:448-452.

Dahshan H, Merwad AM, Mohamed TS. Listeria species in broiler poultry farms: Potential public health hazards. J Microbiol Biotechnol 2016; 26:1551-1556.

Martinez-Suarez JV, Ortiz S, Lopez-Alonso V. Potential impact of the resistance to quaternary ammonium disinfectants on the persistence of Listeria monocytogenes in food processing environments. Front Microbiol 2016; 7:638.

Aras Z, Ardic M. Occurrence and antibiotic susceptibility of Listeria species in turkey meats. Korean J Food Sci Anim Resour 2015; 35:669-673.

Razzaghi R, Rastegar R, Momen-Heravi M, Erami M, Nazeri M. Antimicrobial susceptibility testing of Brucella melitensis isolated from patients with acute brucellosis in a center of Iran. Indian J Med Microbiol 2016; 34:342-345.

Ilhan Z, Solmaz H, Ekin IH. In vitro antimicrobial susceptibility of Brucella melitensis isolates from sheep in an area endemic for human brucellosis in Turkey. J Vet Med Sci 2013; 75:1035-1040.

Abdel-Maksoud M, House B, Wasfy M, Abdel-Rahman B, Pimentel G, Roushdy G, et al. In vitro antibiotic susceptibility testing of Brucella isolates from Egypt between 1999 and 2007 and evidence of probable rifampin resistance. Ann Clin Microbiol Antimicrob 2012; 11:24.

Khazaei Z, Najafi A, Piranfar V, Mirnejad R. Microarray-based long oligonucleotides probe designed for Brucella Spp. detection and identification of antibiotic susceptibility pattern. Electron Physician 2016;8: 2297-2303.

Gautam V, Singhal L, Ray P. Burkholderia cepacia complex: beyond Pseudomonas and Acinetobacter. Indian J Med Microbiol 2011; 29:4-12.

Mahenthiralingam E, Baldwin A, Dowson CG. Burkholderia cepacia complex bacteria: opportunistic pathogens with important natural biology. J Appl Microbiol 2008; 104:1539-1551.

Coutinho HD. Burkholderia cepacia complex: virulence characteristics, importance and relationship with cystic fibrosis. Indian J Med Sci 2007; 61:422-429.

Mohammadi S, Hosseini Jazani N, Ashrafi Babaganjeh L, Kouhkan M. Biosynthesis, characterization of Ag/Cu nanoalloy particles using Lactobacillus casei Subsp. casei and study of antimicrobial activities. Int J Adv Biotechnol Res 2017; 8:1405-1415.

Quinteros MA, Aiassa Martinez IM, Dalmasso PR, Paez PL. Silver nanoparticles: Biosynthesis using an ATCC reference strain of Pseudomonas aeruginosa and activity as broad spectrum clinical antibacterial agents. Int J Biomater 2016; Article ID 5971047.

Camcı MT, Sayar N, Yulug IG, Suzer S. Zn prolongs the stability of antibacterial Silver-Copper nanoalloys. Biochem Biophys 2013; 1:70-77.

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; 275:177-182.

Shrivastava S, Bera T, Roy A, Singh G, Ramachandrarao P, Dash D. Characterization of enhanced antibacterial effects of novel silver nanoparticles. Nanotechnology 2007; 18:225103.

Rudramurthy GR, Swamy MK, Sinniah UR, Ghasemzadeh A. Nanoparticles: Alternatives against drug-resistant pathogenic microbes. Molecules 2016; 21: E836.

Dakal TC, Kumar A, Majumdar RS, Yadav V. Mechanistic basis of antimicrobial actions of silver nanoparticles. Front Microbiol 2016; 7:1831.

Franci G, Falanga A, Galdiero S, Palomba L, Rai M, Morelli G, et al. Silver nanoparticles as potential antibacterial agents. Molecules 2015; 20:8856-8874.

Markowska K, Grudniak AM, Wolska KI. Silver nanoparticles as an alternative strategy against bacterial biofilms. Acta Biochim Pol 2013; 60: 523-530.

Delcour AH. Outer membrane permeability and antibiotic resistance. Biochim Biophys Acta 2009; 1794:808-816.

Zgurskaya HI, Lopez CA, Gnanakaran S. Permeability barrier of Gram-negative cell envelopes and approaches to bypass it. ACS Infect Dis 2015; 1:512-522.

Siritongsuk P, Hongsing N, Thammawithan S, Daduang S, Klaynongsruang S, Tuanyok A, et al. Two-phase bactericidal mechanism of silver nanoparticles against Burkholderia pseudomallei. PloS one 2016; 11:e0168098.

Leid JG, Ditto AJ, Knapp A, Shah PN, Wright BD, Blust R, et al. In vitro antimicrobial studies of silver carbene complexes: activity of free and nanoparticle carbene formulations against clinical isolates of pathogenic bacteria. J Antimicrob Chemother 2012; 67:138-148.

Zhou J, Chen Y, Tabibi S, Alba L, Garber E, Saiman L. Antimicrobial susceptibility and synergy studies of Burkholderia cepacia complex isolated from patients with cystic fibrosis. Antimicrob Agents Chemother 2007; 51:1085-1088.

Ventola CL. The antibiotic resistance crisis: part 2: management strategies and new agents. P T 2015; 40:344-352.

Wang L, Hu C, Shao L. The antimicrobial activity of nanoparticles: present situation and prospects for the future. Int J Nanomedicine 2017; 12:1227-1249.

How to Cite
Mohammadi S, Hosseini Jazani N, Kouhkan M, Ashrafi Babaganjeh L. Antibacterial effects of microbial synthesized silver-copper nanoalloys on Escherichia coli, Burkholderia cepacia, Listeria monocytogenes and Brucella abortus. IJM. 10(3):171-9.
Original Article(s)