Silver Nanoparticle-Based Combinations with Antimicrobial Agents against Antimicrobial-Resistant Clinical Isolates

Area of Science:

• Nanotechnology
• Microbiology
• Pharmacology

Background:

• Rising antimicrobial resistance (AMR) necessitates novel treatment strategies.
• Engineered nanomaterials, like silver nanoparticles (AgNPs), show promise but raise toxicity concerns.
• Limited development of new antimicrobials exacerbates the AMR crisis.

Purpose of the Study:

• To investigate synergistic antimicrobial effects of combining AgNPs with conventional antibiotics.
• To determine the optimal and safe minimum inhibitory concentration (MIC) range for these combinations.
• To assess the cytotoxicity of synergistic combinations in a human hepatocyte model.

Main Methods:

• Testing AgNPs (15-25 nm) against Gram-positive, Gram-negative, and AMR *Klebsiella pneumoniae* strains.
• Evaluating synergistic antimicrobial activity through co-exposure with kanamycin, colistin, rifampicin, and vancomycin.
• Assessing cytotoxicity using a human hepatocyte model.

Main Results:

• AgNPs were effective against Gram-negative bacteria (MIC 16-128 µg/mL) but less so against Gram-positive strains (MIC 256 µg/mL).
• Synergistic effects were observed when combining AgNPs with kanamycin, colistin, and rifampicin against both wild-type and AMR *K. pneumoniae*.
• Combinations showed no to minimal toxicity in the human hepatocyte model.

Conclusions:

• Combining AgNPs with conventional antimicrobials offers a synergistic strategy to combat antimicrobial-resistant bacteria.
• This approach presents a promising avenue for developing new therapies against challenging infections.
• The low observed cytotoxicity suggests a favorable safety profile for potential clinical applications.