The effects of silver nitrate on Mycobacterium abscessus biofilms in a simulated antimicrobial showerhead environment

• DOI: 10.3389/fpubh.2025.1572869
• Publication Date: 2025-05-26T05:17:03Z
• Authors: Sarah Pitell; Cheolwoon Woo; Jill Millstone; Janet Stout; Leanne Gilbertson; Sarah-Jane Haig
• Keywords: Mycobacterium abscessus; Mycobacterium chelonae

Antimicrobial silver materials for drinking water disinfection have become increasingly popular in building-wide systems (e.g., copper-silver ionization) and point-of-use applications containing plumbing fixtures) to combat the microbial growth of associated pathogens that can cause infections immunocompromised (DWPIs). However, evaluations various silver-containing treatments suggest their efficacy is often temporary or incomplete. A potential explanation these observations insufficient dosing into reduce types microorganisms, which are known be more resistant biocides. Instead, sublethal exposure may microorganisms adapt ways increase resistance disinfection. In this study, we assessed effects different concentrations on biofilms clinically environmentally isolated Mycobacterium abscessus , a biofilm-forming member microbiota with public health environmental significance, bench-scale system operated simulated use patterns antimicrobial showerheads. We found high significantly reduced cell densities impacted cellular aggregation behavior, but ultimately made resulting treated non-potable due concentration needed solicit effects. Silver were appropriate limited reduction viable M. . Additionally, transcriptomic analysis revealed genes related stress survival upregulated all experimental conditions: flavoprotein, chaperone, protease synthesis, ribosome cysteine methionine metabolism lower dose condition, peptidoglycan synthesis antioxidant production higher condition. These expressional changes enhance pathogenicity traits after exposure. Overall, our findings indicate drives meaningful biofilm behavior gene expression isolates, yet does not inactivate under conditions.