The Effect of Clinical Environment on the Transport and Antibiotic Resistance of Mycobacteria

Meiyi Zhang, Aayushi Nangia, Jasim Ibrahim, Sandun Fernando, MARIA KING, Texas A&M University

     Abstract Number: 18
     Working Group: Bioaerosols

Abstract
Despite years of clinical care and research and the increasingly recognized role of the environment in spreading pathogens, there remains a significant lack of understanding of the transmission dynamics of mycobacteria that cause lung disease, their survival in air, and movement within the ventilated environments. The thick, mycolic acid-rich cell wall of mycobacteria and their MMPL5 efflux channels hinder drug penetration. Aerosol transmission exposes bacteria to varying airflow, potentially altering membrane protein behavior and drug susceptibility. Although respiratory isolation is standard in health clinics, the resuspension of aerosolized mycobacteria carried in airflows within ventilation systems may change their behavior. Increasing evidence suggests that environmental stressors may contribute to the development of antibiotic resistance in bacteria by mechanisms that are not well understood. However, the environmental effects on the transmission of aerosolized bacteria with antibiotic resistance also remain understudied. Our study focuses on determining how the aerosolization of pathogens at clinical care centers that often have 6-21 air changes per hour affects the transport of mycobacteria and triggers the development of antibiotic resistance. Aerosolized droplet behavior simulated in a hospital-like setting and airflow-induced pressure changes mapped to the cell membrane dynamics of mycobacteria show effects on antibiotic binding. Molecular dynamics simulations and experimental results demonstrate that ventilation airflow related pressure changes cause the opening and rearrangements of membrane channels enabling the release of antibiotics from the cell.