The alarming rise of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) due to the extensive use of antibiotics in healthcare, agriculture, and other sectors poses significant threats to human and animal health, as well as the environment.

New research from Water Research Australia looks at how anaerobic digestion influences the fate and removal of these resistant bacteria in sludge from wastewater treatment plants (WWTP).

In the research, scientists conducted lab-scale experiments using sludge from a full-size WWTP to assess the impact of various anaerobic conditions on ARGs and ARB. The study focused on 10 ARGs from different antibiotic classes and one integrase gene (intI1) of class 1 integron, which plays a role in the horizontal gene transfer of ARGs. The findings revealed that temperature-phased anaerobic digestion (TPAD) and free ammonia (FA) pretreatment significantly reduced ARG levels. TPAD alone achieved a reduction of over 92%, while combining TPAD with FA pretreatment boosted ARG removal by an additional 15%.

These results highlight effective strategies for mitigating the spread of antibiotic resistance through wastewater treatment, offering crucial benefits for public health and environmental protection. Key takeaways from the research, now available for WaterRA members to download, include:

  • Significant reduction of ARGs: TPAD and FA pretreatment can drastically lower the levels of antibiotic-resistant bacteria in sludge.
  • Practical implementation: Incorporating these methods in wastewater treatment plants can help curb the spread of antibiotic resistance.

By adopting these advanced treatment methods, WWTPs can play a pivotal role in safeguarding public health and preserving environmental integrity.

For more detailed information and to learn about integrating these strategies into treatment processes, download the full report.