Monitoring antibiotic resistance genes in wastewater treatment: Current strategies and future challenges

Abstract

Antimicrobial resistance (AMR) is a growing threat to human and animal health.Progress in molecular biology has revealed new and significant challenges for AMR mitigation given the immense diversity of antibiotic resistance genes (ARGs), the complexity of ARG transfer, and the broad range of omnipresent factors contributing to AMR. Municipal, hospital and abattoir wastewater are collected and treated in wastewater treatment plants (WWTPs), where the presence of diverse selection pressures together with a highly concentrated consortium of pathogenic/commensal microbes create favourable conditions for the transfer of ARGs and proliferation of antibiotic resistant bacteria (ARBs). The recent emergence ARBs and ARGs as well as their potential health effects have re-defined the role of WWTPs as a focal point in the fight against AMR. By reviewing the occurrence of ARGs in wastewater and sludge and the current technologies used to quantify ARGs and identify antibiotic resistant bacteria (ARB), this paper provides a research roadmap to address existing challenges in AMR control via wastewater treatment. Wastewater treatment is a double-edged sword that can act as either a pathway for AMR spread or as a barrier to reduce the environmental release of anthropogenic AMR. State of the art ARB identification technologies, such as metagenomic sequencing and fluorescence-activated cell sorting, have enriched ARG/ARB databases, unveiled keystone species in AMR networks, and improved the resolution of AMR dissemination models. Data and information provided in this review highlight significant knowledge gaps. These include inconsistencies in ARG reporting units, lack of ARG/ARB monitoring surrogates, lack of a standardised protocol for determining ARG removal via wastewater treatments, and the inability to support appropriate risk assessment. This is due to a lack of standard monitoring targets and agreed threshold values, and paucity of information on the ARG-pathogen host relationship and potential risk evolution. These research gaps need to be addressed and research 3 findings need to be transformed into practical guidance for WWTP operators to enable effective progress towards mitigating the evolution and spread of AMR.

Inactivation of Antibiotic-Resistant Bacteria in Wastewater by Ozone-Based Advanced Water Treatment Processes

“…The risk of infection by AMRB in water and via the ecosystem and the development of AMRB in the presence of residual antimicrobials or AMRGs in the water environment are now being assessed [ 113 , 114 , 120 ]. Latest research reported the importance of introducing advanced wastewater treatment systems not only for wastewater at STPs but also for hospital effluents from medical facilities [ 30 , 121 , 122 , 123 ]. Meanwhile, it is important to maintain a balance between costs and efficiency by optimizing the operations cost of wastewater treatment along with the management of wastewater treatment plants [ 82 , 124 , 125 ].…”

Routine wastewater-based monitoring of antibiotic resistance in two Finnish hospitals: focus on carbapenem resistance genes and genes associated with bacteria causing hospital-acquired infections

“…Both MGEs and integrons are known to facilitate the mobility of ARGs, suggesting the prevalence of ARGs and the risk of gene transfer in hospital wastewater [23]. Investigating ARG pathogenehost relationships and the prevalence of MGEs and integrons is critical for assessing and monitoring risk [24].…”

Metagenomic analysis of MWWTP effluent treated via solar photo-Fenton at neutral pH: Effects upon microbial community, priority pathogens, and antibiotic resistance genes

“…4 b). According to Nguyen et al (2021) and Raza et al (2021) , ARGs conferring resistance to sulfonamides and tetracyclines are frequently detected in MWWTPE regardless of predominant bacteria taxa, season, and location. Gene sul1 usually prevails in MWW worldwide due to high sequence conservation and transfer among different species ( Wei et al, 2018 ).…”