Synergistic effect of synthesized silver nanoparticles combined with amoxicillin/clavulanic acid against Pseudomonas aeruginosa isolated from clinical samples

Abstract

Abstract Background: Pseudomonas aeruginosa is one of the most prevalent nosocomial pathogenic microorganisms that affect and cause a life-threatening situation. Objective: The study aimed to investigate the synergistic effect of silver nanoparticles (NPs) with amoxicillin/clavulanic acid antibiotic on P. aeruginosa growth. Materials and Methods: A total of 220 clinical samples were collected. A sample has been subjected to isolation and identification by standard microbiological procedures. The extract of Citrus aurantium was used to synthesize silver NPs. The characterization of silver NPs was achieved at the University of Tehran, by using UV–visible spectrophotometry, X-ray diffraction (XRD), and transmission electron microscope (TEM). The antibacterial activity of AgNPs and combination with amoxicillin/clavulanic acid antibiotic were tested against bacteria using the agar well diffusion method. Results: Out of the 220 samples collected, 33 (15%) isolates were positive for P. aeruginosa. Highest resistance of P. aeruginosa was found to amoxicillin/clavulanic acid in percentage of 100. NPs have been characterized by a UV–visible spectrometer which revealed a broad peak at 426 cm-1. XRD showed the purity of the prepared silver NPs that the particle size was equal to 21.26 nm. TEM measurement showed the presence of sphere-like structures with sizes of 20 nm for regular particles and 40 nm for irregular particles. AgNPs, amoxicillin/clavulanic acid, and mixture (amoxicillin/clavulanic acid + AgNPs) have high inhibition activity of P. aeruginosa in concentration of 100 µg/mL and recorded 21.33 ± 3.06, 13.00 ± 0.00, and 22.00 ± 3.46 mm, respectively. Conclusion: The results supported a green synthesis approach for the synthesis of AgNPs with antimicrobial. P. aeruginosa has synergistic combinations of AgNPs with amoxicillin/clavulanic acid, with a great inhibitory effect on the growth of the bacteria.