Metagenomic Analysis of Urban Wastewater Treatment Plant Effluents in Tokyo

Abstract

Urban wastewater treatment plant (WWTP) effluents, even with proper treatment, may cause antimicrobial resistance (AMR) burden, with a high frequency of acquired antimicrobial resistance genes (ARGs). The dissemination of ARGs into the environment increases the risk of infectious diseases; however, there is little direct evidence regarding their epidemiological effects. This study aimed to assess effluents from urban WWTPs around the Tama River and Tokyo Bay using metagenomic analysis of (AMR) genes (ARGs) and heavy-metal resistance genes. Methods: Metagenomic DNA-seq analysis of water samples and resistome analysis were performed. Results: The most prevalent ARG was the sulfonamide resistance gene, sul1, followed by the quaternary ammonium compound resistance gene, qacE, suggesting that basic gene sets (sul1 and ∆qacE) in the class 1 integrons are the predominant ARGs. The aminoglycoside resistance genes, aadA and aph, and macrolide resistance genes, msr(E) and mph(E), were the predominant ARGs against each antimicrobial. bla OXA and bla GES were frequently detected, whereas the bla CTX-M cluster was faintly detected. Non-metric multidimensional scaling plot analysis and canonical correspondence analysis results suggested that marked differences in ARGs could be involved in the seasonal differences; qnrS2, aac(6')-Ib, and mef(C) increased markedly in summer, whereas msr(E) was more frequently detected in winter. Heavy-metal (Hg and Cu) resistance genes (HMRGs) were significantly detected in effluents from all WWTPs. Conclusion:We characterized a baseline level of the environmental ARG/HMRG profile in the overall community, suggesting that environmental AMR surveillance, particularly in urban WWTPs, is a valuable first step in monitoring the AMR dissemination of bacteria from predominantly healthy individuals carrying notable ARG/Bs.

Occurrence and Quantitative Microbial Risk Assessment of Methicillin-Resistant Staphylococcus aureus (MRSA) in a Sub-Catchment of the Yodo River Basin, Japan

“…This suggests that the current spread of MRSA in Japan is not limited to medical institutions, but may be widespread throughout the city as already mentioned [ 16 , 17 , 18 ]. Although the degree of pollutant loading from hospital effluent to STP influent varies greatly from region to region and country to country [ 73 , 74 , 75 , 76 , 77 , 78 ], our results support the need for further conclusive research by taking regional customs, bias, and unknown factors into consideration. In addition, due to the presence of a wide variety of live microorganisms in activated sludge in the biological treatment reactors at STPs [ 79 ], there have been concerns that AMRB could result in a pool of AMRB through zygotic transmission or transformation [ 80 , 81 , 82 ].…”

Comprehensive Genome and Plasmidome Analysis of Antimicrobial Resistant Bacteria in Wastewater Treatment Plant Effluent of Tokyo

“…Sewage effluent samples were collected from eight WWTP sites along the Tama River, Tokyo Bay, and the recreational beach area (BEC1) [ 14 ]. EPB and CPB from fresh 50-mL samples of each effluent ( Figure 1 ).…”

Temporal disturbance of a model stream ecosystem by high microbial diversity from treated wastewater

“…A major public concern about WWTP effluents released into streams is the introduction of antibiotic‐resistant bacteria and ARGs along with their propagation in natural ecosystems (Araújo et al, 2010; Ferreira da Silva et al, 2007; Sekizuka et al, 2022). Our results showed that the added treated wastewater introduced new phyla encoding for stress response systems including antimicrobial resistances.…”