Aerosolization Affects Bacillus globigii Vegetative Cell and Spore Behaviors

Area of Science:

• Environmental microbiology
• Bacterial pathogenesis
• Antimicrobial resistance

Background:

• Antimicrobial resistance (AMR) is a major global health concern.
• The effect of environmental stressors like aerosolization on AMR is not well understood.
• Previous studies indicated aerosolization can induce antibiotic resistance in Gram-negative bacteria.

Purpose of the Study:

• To investigate the impact of aerosolization on the survival and antibiotic resistance of Bacillus globigii, a surrogate for the Gram-positive pathogen Bacillus anthracis.
• To determine how varying aerosolization conditions and durations affect bacterial viability and resistance profiles.
• To compare the effects on both vegetative cells and spores.

Main Methods:

• Aerosolization of Bacillus globigii vegetative cells and spores under various conditions and durations (5-45 min).
• Collection of aerosolized samples using a wetted wall cyclone (WWC) system.
• Analysis through antibiotic susceptibility testing, culture-based assays, and quantitative polymerase chain reaction (qPCR).

Main Results:

• Vegetative cells showed decreased culturability at 5 and 30 min aerosolization.
• Spores exhibited reduced culturability between 15 and 45 min of aerosolization.
• Both cell types demonstrated the lowest antibiotic susceptibility after 15 min of aerosolization.

Conclusions:

• Aerosolization duration and bacterial state (vegetative vs. spores) significantly influence bacterial survival and the development of antibiotic resistance.
• Findings highlight the need to consider aerosolization dynamics in understanding AMR spread.
• This research is crucial for developing strategies to combat airborne antibiotic-resistant bacteria.