Antimicrobial Resistance Genes in the Atmospheric Environment

Antimicrobial resistance (AMR) is one of the most urgent public health threats of our time. While it is commonly associated with hospitals and clinical settings, antibiotic resistance genes (ARGs) can also be found in the environment — including in the air we breathe.

This project focuses on understanding the presence and spread of ARGs in the atmosphere, particularly around wastewater treatment plants and agricultural areas. Using specially designed low-cost 3D-printed air samplers, we collect air samples and analyse them using DNA-based techniques (metagenomics) to identify and measure ARGs and the mobile genetic elements that help them spread between bacteria.

Our goal is to better understand whether these resistance genes are being released into the air, how far they travel, and whether they pose a risk to surrounding communities. We are especially interested in sites where treated waste (biosolids) or agricultural inputs such as biostimulants are used, as these may increase the risk of ARG emissions.

In addition to this core focus, our research also examines how ARG patterns change during extreme weather events like floods, large-scale public events such as music festivals, and under different sample preservation methods. We are also conducting a national-scale assessment of ARGs in wastewater treatment plants across Australia, and a global comparative study of resistance gene mobility spanning wastewater metagenomes from 29 countries.

By uncovering new information about airborne and environmental AMR, our work helps fill key knowledge gaps and supports more informed decisions on environmental health, public safety, and antibiotic stewardship.

Research Outcomes

Five major studies are at various stages of completion:

• Patterns of antibiotic resistance gene (ARG) distribution and risk assessment across Australian wastewater treatment plants — analysis complete, manuscript in preparation
• Temporal dynamics of ARGs during extreme flooding events — manuscript in preparation
• AMR variation associated with large public gatherings (e.g., music festivals) — analysis underway
•  Effects of different preservatives on the stability and metagenomic detection of AMR in environmental samples — manuscript submitted for publication
• Global comparative analysis of resistance gene mobility in wastewater metagenomes across 29 countries — manuscript in preparation

Development and validation of a low-cost 3D-printed active air sampler for ARG surveillance at wastewater treatment plants was published in ACS ES&T Engineering, 2025.

Conference Abstracts

Zhai, N., Li, J., Thomas, K.V. & O’Brien, J.W. Surveillance of antimicrobial resistance in Australian wastewater and air: Integrating national trends and a low-cost monitoring tool, Next Water 2025, Melbourne, Australia, 21-22 October 2025.

Research Outputs

Zhai, N., Li, J., Klümper, U., Lakhey, P., Thomas, K.V. and O’Brien, J.W., 2025. Evaluation of a Low-Cost Active Air Sampler for the Surveillance of Airborne Transmission of Antibiotic Resistance Genes Using a Municipal Wastewater Treatment Plant as a Case Study. ACS ES&T Engineering, 5(9), pp.2260-2268.

Li, J., Ren, J., Li, J., Thai, P.K., Cen, X., Zhao, Z., Zhai, N., Thomas, K.V. and O’Brien, J.W., 2025. Stability of Antibiotics and Their Metabolites in Sewers: Implications for Wastewater-Based Epidemiology and Antibiotic Sustainability. Environmental Science & Technology, 59(33), pp.17796-17810.

Zhai, N., Thomas, K.V., Li, J. and O’Brien, J.W., 2025. Environmental Antimicrobial Resistance: Current Status and Future Prospects. Environmental Contamination: Causes and Solutions, 1(1), p.6.

Li, J., O’Brien, J.W., Tscharke, B.J., He, C., Shimko, K.M., Shao, X., Zhai, N., Mueller, J.F. and Thomas, K.V., 2024. National survey of the occurrence of antimicrobial agents in Australian wastewater and their socioeconomic correlates. Nature Water, 2(12), pp.1166-1177.