Removal of antibiotic resistant bacteria in wastewater treatment plants

Abstract

Antibiotic Resistant Bacteria (ARB) emergence is an increasing threat to public health globally. Wastewater Treatment Plants (WWTPs) play a crucial role in the dissemination of ARB in the environment due to limitations in ARB removal. This study investigated the presence and characteristics of ARB, specifically Extended-Spectrum Beta-Lactamase producing Escherichia coli (ESBL-Ec) and Vancomycin Resistant Enterococci (VRE) , in two WWTPs treating wastewater from hospital and domestic source. The study employed phenotypic and genotypic tests to confirm the presence of ESBL-Ec and VRE, and evaluated their resistance to antibiotics. The results indicated the presence of ESBL-Ec and VRE in both WWTP influent up to (6.0 ± 0.25) x 105 and (1.38 ± 0.25) × 104 CFU/100 mL, respectively, suggesting the potential dissemination of ARB to environment. Although the WWTPs demonstrated relatively high removal efficiencies for ESBL-Ec and VRE up to 4.1 and 5.0 log reduction, respectively, the presence of resistant genes suggested the need for further optimization of treatment processes to mitigate the spread of ARB. The findings highlighted the significance of improved disinfection methods, monitoring antibiotic usage, and implementing robust antimicrobial resistance surveillance systems in WWTPs to minimize the environmental impact associated with ARB dissemination.