Performance of the Municipal Wastewater Treatment Plant for Removal of Listeria monocytogenes

Abstract

The reuse of treated wastewater (TWW) for irrigation is a practical solution for overcoming water scarcity, especially in arid and semiarid regions of the world. However, there are several potential environmental and health-related risks associated with this practice. One such risk stems from the fact that TWW irrigation may increase antibiotic resistance (AR) levels in soil bacteria, potentially contributing to the global propagation of clinical AR. Wastewater treatment plant (WWTP) effluents have been recognized as significant environmental AR reservoirs due to selective pressure generated by antibiotics and other compounds that are frequently detected in effluents. This review summarizes a myriad of recent studies that have assessed the impact of anthropogenic practices on AR in environmental bacterial communities, with specific emphasis on elucidating the potential effects of TWW irrigation on AR in the soil microbiome. Based on the current state of the art, we conclude that contradictory to freshwater environments where WWTP effluent influx tends to expand antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes levels, TWW irrigation does not seem to impact AR levels in the soil microbiome. Although this conclusion is a cause for cautious optimism regarding the future implementation of TWW irrigation, we conclude that further studies aimed at assessing the scope of horizontal gene transfer between effluent-associated ARB and soil bacteria need to be further conducted before ruling out the possible contribution of TWW irrigation to antibiotic-resistant reservoirs in irrigated soils.

High Throughput Profiling of Antibiotic Resistance Genes in Urban Park Soils with Reclaimed Water Irrigation

“…37 In our study, we have observed significantly positive correlations between ARGs and transposase abundance, indicating the potential facilitation of ARGs transfer. Therefore, when considering the impact of RWI, it is necessary not only to assess the abundances of ARGs in RWI soils but also to investigate the abundances of MGEs.…”

“…A plasmid metagenome analysis from the final effluent of a WWTP in Germany has revealed 140 clinically relevant ARGs including genes encoding resistance to aminoglycosides, beta-lactams, fluoroquinolones, macrolides, tetracyclines, and other antibiotics. 37 Previous study has also confirmed that E. coli, K. pneumoniae, and P. mirabilis harbor plasmid-mediated AmpC enzymes. 45 In the present study, f loR gene encoding for FCA resistance (152.7-fold) was highly enriched in the WQT sample compared with WQC sample.…”

“…20,21,37,38 But these approaches have not been amenable to broadspectrum scanning of ARGs in environmental samples. 13 In a recent study on the effect of treated wastewater irrigation on the magnitude of ARGs, six different ARGs (qnrA, tet(O), sulI, sulII, ermB, and ermF) were analyzed using the conventional qPCR method.…”

Wastewater reuse in irrigation: A microbiological perspective on implications in soil fertility and human and environmental health

“…Instead, the few publications available on the subject, show some controversial findings. While Negreanu et al (2012) and Gatica and Cytryn (2013) failed to find any evidences that antibiotic resistant bacteria from treated wastewater could compete or survive in soils after for 6-8 years of irrigation, Wang et al (2014) reported opposite results (Table 4). Wang et al (2014) observed higher diversity and abundance of antibiotic resistance genes in soils irrigated with wastewater than in a pristine soil.…”

Global Experiences on Wastewater Irrigation: Challenges and Prospects

“…In Israel, Nadav et al ( 2013 ) detected that the lowest degree of water repellency was consistently exhibited by the soil with the highest specifi c surface area irrigated with the highest quality wastewater. Gatica and Cytryn ( 2013 ) found that although recent studies seem to indicate that irrigation with wastewater did not signifi cantly induce antibiotic resistance reservoirs in soil, the impact of the abovementioned factors was not yet clear in the context of mobile genes transfer between wastewater-associated bacteria and soil.…”