Potential use of bacteriophages as biocontrol agents against multidrug-resistant pathogens in wastewater treatment: a review

The conventional methods of wastewater treatment are essentially used to remove contaminants and pathogens from wastewater before it is released into the environment or used for other purposes. With the increasing number of Multidrug-Resistant (MDR) organisms in wastewater, the potential usefulness of conventional treatment methods has been re-evaluated. The conventional biological treatment and disinfection have been proven in many studies to increase the prevalence of Antibiotic Resistance Genes (ARG) in bacteria. More than 25 genes responsible for antibiotic resistance were found to be increased from influent to effluent in different Wastewater Treatment Plants (WWTPs). Additionally, many studies have discussed the high abundance of several Mobile Genetic Elements (MGEs) after disinfection by chlorination and ozonation. Bacteriophage-based therapy has emerged as an innovative method for effectively managing microorganisms in wastewater treatment and in various other applications. Bacteriophages can be utilized to kill pathogenic bacteria and eradicate the biofilms formed by the bacteria in wastewater treatment plants with low intrinsic toxicity. However, the use of bacteriophages has been associated with some limitations, including the narrow host range spectrum. This review provides a critical overview of the recent knowledge on the effect of biological treatment and disinfection on spreading antibiotic resistance. In addition, we highlight the interactions among bacteria and phages to sustain the water treatment process. We also emphasize the proposed improvement in wastewater treatment using bacteriophage-based therapy. Our focus is identifying gaps, opportunities, and critical concerns that should be addressed in further research.