Tertiary Wastewater Treatment Processes Can Be a Double-Edged Sword for Water Quality Improvement in View of Mitigating Antimicrobial Resistance and Pathogenicity

Abstract

Despite the high removal efficiency for chemical pollutants by tertiary wastewater treatment processes (TWTPs), there is no definite conclusion in terms of microbial risk mitigation yet. This study utilized metagenomic approaches to reveal the alterations of antibiotic resistance genes (ARGs), virulence factor genes (VFGs), their co-occurrence, and potential hosts during multiple TWTPs. Results showed that the TWTPs reduced chemical pollutants in wastewater, but the denitrifying biofilter (DB) significantly increased the absolute abundances of selected antibiotic-resistant bacteria and ARGs, and simultaneously elevated the relative abundances of ARGs and VFGs through the enrichment of multidrug resistance and offensive genes, respectively. Moreover, the co-occurrence of ARGs and VFGs (e.g., bacA–tapW, mexF–adeG) was only identified after the DB treatment and all carried by Pseudomonas. Then, the ultraviolet and constructed wetland treatment showed good complementarity for microbial risk reduction through mitigating antibiotic resistance and pathogenicity. Network and binning analyses showed that the shift of key operational taxonomic units affiliating to Pseudomonas and Acinetobacter may contribute to the dynamic changes of ARGs and VFGs during the TWTPs. Overall, this study sheds new light on how the TWTPs affect the antibiotic resistome and VFG profiles and what TWTPs should be selected for microbial risk mitigation.

Nitrogen Removal Performance and Microbial Response of Anammox Under Multiantibiotic Stress: Effect of Static Magnetic Field

“…Although ARG hosts during biological wastewater treatment vary in studies due to different operational parameters and antibiotics, heterotrophic denitrifiers reportedly exhibit strong associations with ARGs and serve as potential hosts. 34,41 However, it was also reported that the anammox bacterium Candidatus Brocadia is a host of SDZ and chlortetracycline resistance genes. 31 Herein, anammox bacteria were negatively correlated with most ARGs, which was contrary to the above finding.…”

Nanosilver-Induced Pseudo Cuproptosis of Potentially Pathogenic Bacteria during the Storage of Ozone-Treated Wastewater

“…Wastewater reuse, especially for agricultural irrigation in regions facing water scarcity such as the Middle East, North Africa, the Indian subcontinent, and the arid regions of northern China, holds significant importance . Efforts have been made to upgrade wastewater treatment plants to tertiary treatment levels in order to improve the water quality for agricultural irrigation . Among the techniques used in tertiary treatment to remove organic micropollutants from secondary wastewater, ozone stands out and is being widely adopted. − However, several studies have indicated that even after ozone oxidation, pathogenic bacteria, such as Gram-negative bacteria, can remain in the wastewater and regrow during storage, leading to quantities equal to or even exceeding those found in untreated secondary wastewater. − Recent research has attempted to address this issue by introducing natural competition as a method .…”

“…1 Efforts have been made to upgrade wastewater treatment plants to tertiary treatment levels in order to improve the water quality for agricultural irrigation. 2 Among the techniques used in tertiary treatment to remove organic micropollutants from secondary wastewater, ozone stands out and is being widely adopted. 3−5 However, several studies have indicated that even after ozone oxidation, pathogenic bacteria, such as Gram-negative bacteria, can remain in the wastewater and regrow during storage, leading to quantities equal to or even exceeding those found in untreated secondary wastewater.…”