Localized Hotspot Management: Hand-Held Phage Aerosols as a Complementary Strategy for Carbapenem-Resistant...

Area of Science:

• Microbiology
• Infectious Diseases
• Biotechnology

Background:

• Carbapenem-resistant Acinetobacter baumannii (CRAB) poses a significant threat in healthcare settings due to surface persistence and resistance to disinfectants.
• Bacteriophages (phages) offer a specific and lytic alternative for biocontrol against CRAB.

Purpose of the Study:

• To evaluate a personal hand-held vibrating mesh nebulizer (VMN) for rapid, localized delivery of phage aerosols.
• To assess phage stability, viability during nebulization, and surface decontamination efficacy against CRAB.

Main Methods:

• Two lytic phages (ϕ2 and ϕ11) were tested for stability under various storage conditions (4 °C, -20 °C).
• Phage viability was assessed during VMN operation.
• Surface decontamination efficacy was evaluated using varying spray parameters and phage concentrations.

Main Results:

• Phages demonstrated optimal stability at 4 °C; storage at -20 °C reduced infectivity significantly.
• VMN aerosolization did not compromise phage viability.
• A 3-minute spray achieved >99.9% CRAB reduction, with ϕ2 effective at 1x10^7 PFU/mL and ϕ11 at 1x10^8 PFU/mL.
• Residual ϕ2 provided protection against recolonization for at least 24 hours, while ϕ11 protection lasted 6 hours.

Conclusions:

• The hand-held VMN is a practical, cost-effective platform for delivering viable phage aerosols.
• This method complements large-scale disinfection, offering targeted infection control in healthcare environments.
• Phage aerosols show potential for sustained surface decontamination and prevention of CRAB recolonization.