Synergistic antibacterial activity of biogenic AgNPs with antibiotics against multidrug resistant bacterial strains

Abstract

The prevalence of hospital-acquired infections caused by drug resistant bacterial pathogens is a major health risk, leading to a considerable number of deaths and illnesses globally. Therefore, it is essential to develop new combinations of antimicrobial agents to effectively manage drug-resistant bacteria that are responsible for nosocomial infections. A current study aims to synthesize silver nanoparticles (AgNPs) from the seeds of Trigonella foenum-graecum (fenugreek). The AgNPs exhibited a spherical morphology and had an average particle size of 29.75 nm. In addition, XRD examination verified the presence of a face-centered cubic (fcc) lattice structure in the biosynthesized AgNPs, while FTIR study demonstrated the existence of several functional groups such as phenols, alkanes, and amines. The biogenic AgNPs exhibited the most potent antibacterial effect against E. coli strain, with relative inhibitory zone of 18.43 ± 0.35 mm and a minimum inhibitory concentration (MIC) of 50 µg/ml. In addition, the most potent antibacterial effect of AgNPs combined with colistin was observed against Acinetobacter baumannii strain, while the greatest combined efficacy of AgNPs with norfloxacin was found against Pseudomonas aeruginosa, resulting in a relative increase in the fold of inhibition area (IFA) of 0.53 and 0.35, respectively. In conclusion, the potent antibacterial and synergistic effect of AgNPs with antibiotics highlights their potential application of this combination in controlling nosocomial infections in health care settings.