Increased use of Quaternary Alkylammonium Compounds during the SARS-CoV-2 Pandemic: Impact on Environmental Concentrations and Multi-resistance Development in Pathogenic and Environmental Bacteria

• Applicants: Dr. Stefanie P. Glaeser; Professorin Dr. Ines Mulder
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management ; Soil Sciences ; Microbial Ecology and Applied Microbiology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 458460392

Quaternary alklyammonium compounds (QAAC) are a central ingredient of many disinfectants and surfactants and it has been known that they are not completely degraded during waste water treatment. Instead, they can accumulate in sewage sludge, soils and sediments. Several pathogenic bacteria have already acquired QAAC resistance. Also, resistance genes have been found widespread in wastewater treatment plants and receiving environments. A key concern is the genetic linkage of QAAC- and antibiotic resistance genes. The biocidal activity of QAACs has already raised concerns about their environmental effects before the SARS-CoV-2 pandemic. However, with considerably increased QAAC consumption, potential risks in the environment are amplified with the pandemic, with currently incalculable consequences for public health. Therefore, our projects aims at answering the following hypothesis: (1) As a consequence of the SARS-CoV-2 pandemic, concentrations of QAAC reaching the environment via wastewater effluent or sewage sludge rise. (2) Increased disinfectant concentrations in waste water treatment plants enhance the development of QAAC- and antibiotic multi-resistance in potential pathogens and environmental bacteria. (3) Increasing QAAC concentrations inhibit microbial degradation of antibiotics, with unknown consequences for the selection of antibiotic resistance.In this project, we will monitor the increase of QAAC concentrations with the onset of the SARS-CoV-2 pandemic in WWTPs and receiving environments and their effects on antibiotic resistance gene spread and multi-resistance in potential pathogenic and environmental bacteria which came in contact with QAACs. Our sample sets include, among others, monthly collected particulate suspended matter from the river Saar as well as waste water influent and effluent, waste water irrigated soils from Mexico City sampled before and after March 2020 – both located at or near national and international SARS-CoV-2 hot spots. Due to the importance of the environmental impact of QAACs, incubation experiments with soils and river water will accompany monitoring data and help to clarify their effects on the degradation of pharmaceuticals as well as antibiotic and multi-resistance development in bacteria.In a multidisciplinary approach, our study will identify the QAAC footprint and will help to get a realistic picture of QAAC associated risks in the environment that arise from the SARS-CoV-2 pandemic.

• DFG Programme: Research Grants