Optimized Design to Reduce Environmental Effects on Bioaerosols

Meiyi Zhang, Tatiana Baig, BROOKE SMITH, Hyoungmook Pak, Gabriela Ramos, Violette Ramirez, Sunil Kumar, David Klassen, Maria King, Texas A&M University

     Abstract Number: 45
     Working Group: Aerosol Science of Infectious Diseases: What We Have Learned and Still Need to Know about Transmission, Prevention, and the One Health Concept

Abstract
Illnesses caused by airborne pathogens, including the recent SARS-CoV-2 coronavirus pandemic and frequent outbreaks of bacterial illnesses, have severe human health consequences, and require effective treatment strategies. However, antiviral drugs are limited, and few novel antibiotic classes are in development today. Viral infectivity and antimicrobial resistance (AMR) of bacteria pose increasing threat to global public health. Even though antibiotics, metals, and other pollutants are the main drivers for AMR development, growing evidence suggests that other environmental stressors such as air conditioning airflow may contribute to triggering resistance in pathogens. Due to mechanical and molecular forces, deposition, resuspension, attachment, and detachment from surfaces may change the behavior of bioaerosols in ventilation airflow. Our study using biolayer interferometry and molecular dynamics simulation demonstrates that different environmental conditions affect the binding kinetics of the spike (S) protein and receptor binding domain (RBD) of SARS-CoV-2 to different surface materials. Test results with bacterial aerosols show that aerosolization not only exerts mechanical stress on bacteria, but also affects their cell membrane, indicating correlation with the airflow triggering resistance to antibiotics that inhibit cell wall synthesis. Although bacteria are robust creatures, environmental conditions, including the direction of airflow can be manipulated to disrupt their proliferation. The layout of a facility will directly affect whether the rooms are more likely to become contaminated with aerosolized pathogens or not. Of greatest concern in food processing facilities and healthcare settings is the possibility of generating bioaerosols containing resistant pathogens. Therefore, it is critical to optimize the airflow patterns to minimize the entrainment and residence time of contaminated air. Computational airflow models recently developed in this study show that facility layout strongly affects the transport and behavior of bioaerosols, opening new avenues for engineering to reduce the adverse responses triggered by environmental effects and combat their spread.