Ampicillin-augmented Silver Nanoparticles for Synergistic Antimicrobial Response: A Promising Therapeutic Approach

Abstract

Aims: Globally, scientists are working to find more efficient antimicrobial drugs to treat microbial infections and kill drug-resistant bacteria.

Background: Despite the availability of numerous antimicrobial drugs, bacterial infections still pose a serious threat to global health. A constant decline in the effectiveness of antibiotics owing to their repeated exposure as well as a short-lasting antimicrobial activity led to the demand for developing novel therapeutic agents capable of controlling microbial infections.

Objective: In this study, we report the antimicrobial activity of chemically synthesized silver nanoparticles (cAgNPs) augmented with ampicillin (amp) in order to increase antimicrobial response against Escherichia coli (gram -ve), Staphylococcus aureus (gram +ve) and Streptococcus mutans (gram +ve).

Methods: Nanostructure, colloidal stability, morphology and size of cAgNPs before and after functionalization were explored by UV-vis spectroscopy, FT-IR, zeta potential and TEM. The formation and functionalization of cAgNPs were confirmed from UV-vis spectroscopy and FT-IR patterns. From TEM, the average sizes of cAgNPs and cAgNP-amp were found to be 13 and 7.8 nm, respectively, and change in colloidal stability after augmentation was confirmed from zeta potential values. The antimicrobial efficacies of cAgNP-amp and cAgNPs against E. coli S. aureus and S. mutans were studied by determining Minimum Inhibitory Concentrations (MICs), zone of inhibition, assessment of viable and non-viable bacterial cells and quantitative assessment of biofilm.

Results & discussion: Our results revealed cAgNP-amp to be highly bactericidal compared to cAgNPs or amp alone. The nano-toxicity studies indicated cAgNP-amp to be less toxic compared to cAgNPs alone.

Conclusion: This study manifested that cAgNPs show synergistic antimicrobial effects when they get functionalized with amp suggesting their application in curing long-term bacterial infections.

Keywords: Silver nanoparticles; ampicillin; antimicrobial efficacy; augmentation; bacterial infection; drugs..