Silver Nanoclusters Decrease Bacterial Resistance to Heavy Metals and Antibiotics

Area of Science:

• Biomedical Research
• Nanotechnology
• Microbiology

Background:

• Nanomaterials are utilized in biomedicine as carriers and possess antimicrobial properties.
• Silver nanoclusters (AgNCs) were hypothesized to interact with the TolC protein, crucial for multidrug resistance in bacteria.

Purpose of the Study:

• Synthesize and characterize glutathione-coated AgNCs.
• Evaluate the toxicological effects of AgNCs on bacterial strains.
• Investigate the impact of AgNCs on bacterial resistance to heavy metals and antibiotics.

Main Methods:

• Synthesis and characterization of AgNCs (2.2 ± 0.5 nm diameter).
• Microplate assays to assess toxicity against five bacterial strains.
• Testing AgNCs in combination with heavy metal salts and antibiotics.

Main Results:

• AgNCs showed no significant growth inhibition at concentrations used for resistance assays (≤2.5 µg/mL Ag).
• A notable decrease in bacterial resistance to copper (II), cadmium (II), erythromycin, and levofloxacin was observed with AgNCs.
• A dose-dependent relationship was established between AgNC concentration and bacterial resistance modulation.

Conclusions:

• AgNCs can act as inhibitors of bacterial resistance to heavy metals and antibiotics.
• These findings may aid in understanding bacterial adaptation and developing strategies against multidrug resistance.
• AgNCs show promise for future applications in combating bacterial resistance mechanisms.