Civil Engineering Departmental Seminar - Characterizing and Predicting Antibiotic Resistance Gene Fate during Disinfection Processes: Insights and Implications for (Waste)Water Treatment, Healthcare, and Beyond

Characterizing and Predicting Antibiotic Resistance Gene Fate during Disinfection Processes: Insights and Implications for (Waste)Water Treatment, Healthcare, and Beyond

Disinfection processes are key barriers to the spread of viable antibiotic resistant bacteria (ARB) and their antibiotic resistance genes (ARGs) within environmental systems and human populations. Although increasing attention has been paid to the fates of ARB and ARGs during exposure to various disinfectants, there remains an incomplete understanding of fundamental kinetic parameters governing ARG elimination during disinfection, consequent impacts on ARGs’ biological activities, and key factors which may influence the relative efficiencies of such processes in practice. Our work has helped to address these knowledge gaps through systematic evaluations of the degradation and “deactivation” (i.e., biological activity loss) of a broad cross-section of ARGs during exposure to many of the disinfectants most commonly-used in (waste)water treatment, as well as in healthcare and personal care. Our investigations show that (a) kinetics of ARG (and more generally, DNA) degradation and deactivation by many chemical and physical disinfectants exhibit strong dependencies on the abundance of certain nucleotide targets (e.g., interstrand AT or GC bps, and intrastrand 5’-bipyrimidine-3’ or 5’-GG-3’ doublets) within the ARGs’ DNA sequences, and (b) that these dependencies can in turn provide the basis for quantitative models enabling accurate prediction of rate constants governing ARG degradation and deactivation kinetics under realistic treatment conditions (including during full-scale disinfection of municipal wastewater). Observations from this work also provide important insights into heretofore underappreciated and/or unrecognized factors governing the relative efficiencies of ARG degradation and deactivation during various (waste)water disinfection processes (particularly during chlorination of non-nitrified/ammonia-rich wastewater), and have significant implications for control of ARB and their ARGs during such processes. This talk will provide an overview of key findings and conclusions from our studies, and how this information can be used to improve decision-making regarding antibiotic resistance control when selecting, designing, and operating disinfection processes for (waste)water treatment and reuse, as well as for personal care and healthcare.