Search

Abstract: In this study, solid phase extraction (SPE) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) were utilized to develop a rapid, sensitive and reliable method for trace analysis of 21 antibiotics belonging to 7 classes in influent and effluent of municipal wastewater treatment plant. Detection parameters for SPE preconcentration and UPLC-MS/MS analysis were optimized, including sample pH, eluant, mobile phase (solvent and formic acid concentration), column temperature, and flow rate. Under the optimal conditions, the recoveries for different antibiotics ranged from 60.5% to 109.7% and all analytes were detected within 10.0min by UPLC-MS/MS. The validation study indicated that the method detection limits (MDLs) for the 21 antibiotics were from 0.3 to 60.0ngL−1 for effluent, while higher MDLs (0.5–84.0ngL−1) for influent. Accuracy and precision for both within-run (−11.6 to 14.3% and 0.2 to 15.6%) and between-run tests (−7.2 to 8.7% and 1.9 to 16.4%) were acceptable. The analysis of influent and effluent samples of two municipal wastewater treatment plants in Hong Kong revealed the presence of 11 antibiotics, including ampicillin, cefalexin, sulfamethoxazole, sulfadiazine, norfloxacin, ciprofloxacin, ofloxacin, tetracycline, roxithromycin, erythromycin-H2O, and trimethoprim. Their concentration ranged from 3.5 to 720.0ngL−1 in influent and from 2.1 to 556.4ngL−1 in effluent. [Copyright &y& Elsevier]

• We collected time-series influent, AS and effluent for metagenomic sequencing. • Prevalence of ARGs and MGEs was examined in effluents from global cities. • An online platform integrating the resistome risk ranking scheme was developed. • ARG variants with high risk were characterized in effluents. Wastewater treatment plants (WWTPs) are regarded as critical points in disseminating antibiotic resistance genes (ARGs). In particular, the discharging effluents from WWTPs generally bring downstream catchment areas exogenous ARGs and resistant bacteria. However, there lacks a sufficient assessment of the resistome and mobilome in effluents. In this study, a consecutive monthly sampling was conducted over 13 months in three Hong Kong (HK) WWTPs for metagenomic sequencing. Prevalence information of ARGs and mobile genetic elements (MGEs) was compared with counterparts in effluents from cities of North America, South America, Europe, and Asia. Moreover, a publicly accessible platform integrating the exposure ranking scheme, which was based on the global archive of ARG abundance, and a readily implementable online pipeline was developed to benefit communication in academia and government consultancy. Results demonstrated HK WWTPs were featured high ARG removal efficiency of 2.34–2.43 log reduction rate, and effluents were ranked in moderate levels of Level 2 and Level 3 in the exposure prioritizing scheme based on total ARG abundance. Moreover, absolute quantification of temporal variations of effluent resistome disclosed distinct changes over time among varied ARG types which were associated with prevalently used antibiotics, including quinolone and sulfonamide. This reinforces the need for real-time management of WWTP systems. Notably, ARGs of anthropogenic prevalence, high mobility, and potential pathogenicity were found to be present in HK effluents, drawing attention to the necessity for improved risk management. In addition, source tracking of effluent resistome and structural equation model analysis was conducted to explore the disparity in ARG abundance and diversity in different samples. The discovery of this study and the recommendation of a comprehensive exposure assessment will facilitate decision-making in resistome management in WWTPs to reduce the ARG and antibiotic resistant bacteria (ARB) contamination in the receiving environments. [Display omitted] [ABSTRACT FROM AUTHOR]