A Sustainable Combined Approach to Control the Microbial Bioburden in the School Environment

Area of Science:

• Environmental microbiology
• Indoor air quality
• Public health

Background:

• School environments harbor dynamic microbial ecosystems, including pathogens, impacting student health.
• Inadequate ventilation and chemical sanitizers contribute to indoor bioburden and antimicrobial resistance (AMR).
• Sustainable alternatives are needed to improve classroom microbial quality and reduce health risks.

Purpose of the Study:

• To evaluate the impact of plants, mechanical ventilation, and probiotic-based sanitation (PBS) on indoor bioburden and air quality in a school setting.
• To assess the effectiveness of these interventions in reducing pathogens and AMR.
• To compare the efficacy of PBS with conventional chemical sanitation.

Main Methods:

• A pre-post case-control study was conducted over one year in an Italian high school.
• Microbial monitoring using culture-dependent and -independent methods assessed bioburden and air quality.
• Interventions included introducing plants, a mechanical ventilation system, and PBS as a replacement for chemical sanitation.

Main Results:

• Baseline bioburden was high, dominated by Staphylococcus spp. and fungi.
• Plants showed a modest reduction in fungal contamination.
• Mechanical ventilation and PBS significantly decreased pathogen levels by over 80% (p < 0.001) and AMR by up to 3 Log10 (p < 0.001).

Conclusions:

• Combined strategies, particularly ventilation and PBS, are effective in improving indoor microbial quality in schools.
• Probiotic-based sanitation offers a sustainable and effective alternative to chemical methods for controlling bioburden and AMR.
• These findings support the use of PBS for enhancing health in indoor environments, including non-sanitary settings.