Tuning of antimicrobial property of commercial drugs by use of bio- synthesized noble metal nanoparticles

Abstract

Silver nanoparticles are known to have antimicrobial and antifungal properties. Here we explore the effect of biogenic silver (AgNPs) and gold nanoparticles (AuNPs) on the antimicrobial property of drugs namely Vancomycin, Ampicillin and Tetracyclin, by measuring their zone of inhibition in disk diffusion studies against Escherichia coli, Enterococcus faecalis and Staphylococcus aureus. The different AuNPs and AgNPs used were synthesized using aqueous extracts of floral parts of Tecoma stans, Caesalpinia sappan, Tagetus erecta. The bacterial strains were spread on agar plates and the disks impregnated with known concentration of drug were used for disk diffusion studies and well diffusion studies. 20nm & 200nm commercially available AuNPs and AgNPs were also used along with drugs for disk diffusion studies and the results were compared. Different nanoparticles had different effect on drug's antimicrobial activity. The range of tunability of antimicrobial activity of drug achieved by using the biogenic nanoparticles was more than that of commercial nanoparticles. E.coli and S.aureus are known to gain resistance against Ampicilin and Vancomysin respectively. In this work, the effect of Ampicillin on E.coli and the effect of Vancomysin on S.aureus could be restored by using it along with our nanoparticles. Thus we propose a safe and simple method to increase or decrease drug's activity against specific microbe.