Microbial silver resistance mechanisms: recent developments

Area of Science:

• Microbiology
• Biochemistry
• Materials Science

Background:

• Silver ions and nanoparticles are widely used as antimicrobial agents.
• Understanding microbial resistance to silver is essential due to its increasing application.
• Silver's efficacy extends to bacteria, fungi, viruses, and biofilms.

Purpose of the Study:

• To review the antimicrobial applications of silver compounds.
• To discuss molecular mechanisms of microbial silver resistance in bacteria and fungi.
• To explore silver's role in combating biofilms and viral infections, including SARS-CoV-2.

Main Methods:

• Literature review of recent studies on silver antimicrobial activity and resistance.
• Analysis of molecular mechanisms of silver resistance in bacteria (sil operon, efflux systems) and fungi (metallothioneins, ATPases).
• Discussion of evolutionary engineering studies on rapid silver resistance development.

Main Results:

• Silver ions and nanoparticles exhibit distinct antimicrobial properties and resistance mechanisms.
• Bacterial resistance involves specific genes and efflux systems; fungal resistance involves metallothioneins and cell wall components.
• Exopolysaccharides play a role in bacterial biofilm defense against silver nanoparticles.
• Rapid evolution of silver resistance and cross-resistance to other agents observed in microbes.
• Silver compounds are effective against microbial biofilms and possess antiviral properties.

Conclusions:

• Silver compounds are vital antimicrobials, necessitating a comprehensive understanding of resistance.
• Detailed knowledge of microbial silver response and ecological impact is critical for safe and effective use.
• Further research into silver's antimicrobial mechanisms and resistance evolution is warranted.