Pharmaceuticals in Wastewater Treatment Plants: A Systematic Review on the Substances of Greatest Concern Responsible for the Development of Antimicrobial Resistance

Abstract

In recent years, there is a growing concern about the alarming spread of antimicrobial resistance (AMR) in different environments. Increasingly, many species of bacteria, fungi and viruses are becoming immune to the most commonly used pharmaceuticals. One of the causes of the development of the resistance is the persistence of these drugs, excreted by humans, in municipal and hospital wastewater (WW). Consequently, wastewater treatment plants (WWTPs) are a primary source of antimicrobial resistance genes as novel pollutants. This systematic review sought to examine the relevant literature on pharmaceutical residues (PRs) responsible for AMR in municipal and hospital WW in order to propose a classification of the PRs of greatest concern and provide an updated source for AMR management in WWTPs. Among 546 studies collected from four databases, 18 were included in the present review. The internal and external validity of each study was assessed, and the risk of bias was evaluated on a 20-parameter basis. Results were combined in a narrative synthesis discussing influent and effluent PR concentrations at 88 WWTPs, seasonal variations, differences between hospital and municipal WW, environmental risk assessment values of antimicrobial substances and treatment facilities removal efficiencies. Among the 45 PRs responsible for AMR evaluated in this study, the antibiotics ciprofloxacin, clarithromycin, erythromycin, metronidazole, ofloxacin, sulfamethoxazole and trimethoprim constitute a considerable risk in terms of ubiquitous distribution, worrying concentrations, risk quotient values and resistance to removal treatments. Gaps in knowledge, data and information reported in this review will provide a valuable source for managing AMR in WWTPs.

Occurrence and Effects of Antimicrobials Drugs in Aquatic Ecosystems

“…The presence of antimicrobials in aquatic ecosystems (Figure 1) is essentially linked to the excretion of unmetabolized antimicrobials by humans and animals [49], direct introduction by aquaculture [50] and inadequate disposal at the hospital level [49].…”

Preparation of Chitosan-Modified Bentonite and Its Adsorption Performance on Tetracycline

“…Tetracycline (TC) is a broad-spectrum antibiotic with a polycyclic tetraphenyl carboxamide structure that is widely used in livestock and aquaculture, but its extensive use and misuse not only causes cytotoxicity to plants and animals but also leads to the spread of resistance genes and even threatens human health . In recent years, researchers have found different concentrations of TC in domestic sewage and industrial wastewater. , Some studies have reported that the TC content in pharmaceutical wastewater has reached 100–500 mg/L . If the treatment of TC wastewater is not complete, it will lead to an increase in residues in the environment year by year, posing a great threat to human health and the ecological environment .…”

“…2 In recent years, researchers have found different concentrations of TC in domestic sewage and industrial wastewater. 3,4 Some studies have reported that the TC content in pharmaceutical wastewater has reached 100−500 mg/L. 5 If the treatment of TC wastewater is not complete, it will lead to an increase in residues in the environment year by year, posing a great threat to human health and the ecological environment.…”

Review of Antimicrobial Resistance in Wastewater in Japan: Current Challenges and Future Perspectives

“…In terms of One Health, wastewater is an important reservoir of AMR because it contains various AMR from humans, animals, and environments [ 5 ]. The residual antimicrobials in wastewater that are used in humans, animals, and crop plants also are of great concern because they can drive the development and spread of AMR as a result of the selective pressure on bacteria, although the dynamics remain poorly understood [ 6 , 7 , 8 , 9 , 10 ]. A recent metagenomic analysis of ARGs in untreated sewage around the world revealed a higher abundance of ARGs in wastewater in low- and middle-income countries (LMICs) than in high-income countries (HICs), reflecting the state of sanitation and general health [ 11 ].…”