RT Journal Article SR Electronic T1 Mechanisms of Listeria monocytogenes disinfection with Benzalkonium chloride: from molecular dynamics to kinetics of time-kill curves JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.06.21.497115 DO 10.1101/2022.06.21.497115 A1 Martín Pérez-Rodríguez A1 Marta L. Cabo A1 Eva Balsa-Canto A1 Míriam R. García YR 2022 UL http://biorxiv.org/content/early/2022/06/23/2022.06.21.497115.abstract AB Unravelling the mechanisms of action of disinfectants is essential to optimize dosing regimes and minimize the emergence of antimicrobial resistance. In this work, we decipher the mechanisms of action of a commonly used disinfectant - benzalkonium chloride (BAC)-over a major pathogen -L. monocytogenes-in the food industry. For that purpose, we use modeling at multiple scales, from the cell membrane to the cell population inactivation. Molecular modeling reveals that the integration of the BAC into the membrane requires three phases: (1) the BAC approaches the cellular membrane, (2) the BAC is adsorbed on its surface, and (2) it is rapidly integrated into the lipid bilayer, where it remains at least for several nanoseconds, probably destabilizing the membrane. We hypothesize that the equilibrium of adsorption, although fast, is limiting for sufficiently large BAC concentrations, and a kinetic model is derived to describe kill curves of a large population of cells. The model is tested and validated with time series data of free BAC decay and time-kill curves of L. monocytogenes at different inocula and BAC dose concentrations. The knowledge gained from the molecular simulation plus the proposed kinetic model offers the means to rationally design novel disinfection processes.IMPORTANCE Disinfection is fundamental to guarantee food safety, but the misuse or overuse of common biocides in the food industry, such as benzalkonium chloride, can act as drivers of antimicrobial resistance. Selective pressure associated with exposure to benzalkonium chloride may result in adaptation to quaternary amine compounds or even cross-resistance to other antibiotics such as ciprofloxacin. Therefore, understanding the mechanisms of action of disinfectants is crucial to determining the optimal dosing regimens to ensure safety while minimizing the levels of disinfectant residue after treatment.