Phage treatment and wetland technology as intervention strategy to prevent dissemination of antibiotic resistance in surface waters

Urban wastewater contains antibiotic residues and human-derived microorganisms, including well-known human disease causing bacteria (pathogens) which are resistant to antibiotics. These may withstand either traditional treatment in waster water treatment plants or passive treatment in constructed wetlands presenting a serious health risk particularly in Low to Middle Income Countries (LMIC).

In this proposed research, the Phageland consortium aims to develop a new low-cost, safe, eco-friendly and scalable intervention strategy to prevent the transmission of antibiotic resistance (AR) from wastewater into surface waters. This will be achieved by combining the use of specific bacteria-infecting viruses (bacteriophages also known as phages) to created a phage-based treatment in combination with constructed wetlands acting as passive water treatment systems.

The research partners will evaluate this technology with respect to its efficacy in removing key antibiotic resistant pathogens from wastewater, ecological safety, including preservation of natural bacterial diversity, and potential side effects for the wider environment including animals.

The PhageLand technology will also be tested in a scaled-up pilot infrastructure as a proof-of-concept for the strategy and its viability for deployment in LMICs where economic constraints limit the construction of more costly and power hungry treatment technologies. The project will use a combination of field and laboratory experiments, including cutting edge techniques and environmental engineering, to address current gaps in knowledge and both assess and develop the PhageLand technology.

The initial focus will be on post-Soviet European LMICs, and specifically Moldova as a model country, which have historically been overlooked amongst LMICs as a whole. However, the proposed technology will be universally applicable and easily transferred to other countries regardless of economic status.

PhageLand aims to develop a novel intervention strategy combining the low-cost and eco-friendly purification capacity of passive treatment systems, namely constructed wetlands (CW), with a dedicated phage-based treatment to prevent the transmission of antibiotic resistance (AR) from wastewater into surface waters. PhageLand includes public health investigations targeting multidrug-resistant bacterial (ARB) pathogens in low-middle income countries (LMICs) in Eastern Europe. The phage-based treatment will be specifically tailored to eliminate these multidrug-resistant pathogens from wastewater.

In parallel, PhageLand aims to assess: a) the self-purification capacity of model full-scale CWs operating in Spain and Moldova in removing antibiotic residues, ARB and antibiotic resistance genes (ARGs); and b) the potential risk associated with the dissemination of ARB and ARGs within indigenous bacterial communities and among animals inhabiting CWs. Experimental tasks will include field and laboratory experiments involving cutting-edge chemical, biotechnological and (meta)genomic techniques as well as animal testing.

Finally, a pilot-scale infrastructure will be used to scale-up the PhageLand technology and to assess its performance under real environmental conditions. This proof-of-concept will be used to demonstrate the efficacy and scalability of this nature-based technology for combating AR and to encourage stakeholders for its implementation in wastewater treatment, particularly in LMICs where costly and power-demanding treatment plants are difficult to set up.