Determinants of presence and removal of antibiotic resistance genes during WWTP treatment

Determinants of presence and removal of antibiotic resistance genes during WWTP treatment: A cross-sectional study

Pallares Vega, R. (TU Delft BT/Environmental Biotechnology; Wetsus, Centre for Sustainable Water Technology)
Blaak, Hetty (Universiteit Utrecht)
van der Plaats, Rozemarijn (Universiteit Utrecht)
de Roda Husman, Ana M. (Universiteit Utrecht)
Hernandez Leal, Lucia (Wetsus, Centre for Sustainable Water Technology)
van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology)
Weissbrodt, D.G. (TU Delft BT/Environmental Biotechnology)
Schmitt, Heike (Wetsus, Centre for Sustainable Water Technology; Rijksinstituut voor Volksgezondheid en Milieu (RIVM); Universiteit Utrecht)

2019

Wastewater treatment plants (WWTPs), linking human fecal residues and the environment, are considered as hotspots for the spread of antimicrobial resistance (AMR). In order to evaluate the role of WWTPs and underlying operational parameters for the removal of AMR, the presence and removal efficiency of a selected set of 6 antimicrobial resistance genes (ARGs) and 2 mobile genetic elements (MGEs) was evaluated by means of qPCR in influent and effluent samples from 62 Dutch WWTPs. The role of possible factors impacting the concentrations of ARGs and MGEs in the influent and their removal was identified through statistical analysis. ARGs and the class I integron-integrase gene (intI1) were, on average, removed to a similar extent (1.76 log reduction) or better (+0.30–1.90 logs) than the total bacteria (measured as 16S rRNA gene). In contrast, broad-host-range plasmids (IncP-1) had a significantly increased (p < 0.001) relative abundance after treatment. The presence of healthcare institutions in the area served did only slightly increase the concentrations of ARGs or MGEs in influent. From the extended panel of operational parameters, rainfall, increasing the hydraulic load of the plant, most significantly (p < 0.05) affected the treatment efficiency by decreasing it on average −0.38 logs per time the flow exceeded the average daily flow. Our results suggest that overall, WWTP treatments do not favor the proliferation of the assessed resistance genes but might increase the relative abundance of broad-host-range plasmids of the IncP-1 type.

ARGs
IncP plasmids
MGE
Process design
Rainfall
Removal efficiency
WWTPs

http://resolver.tudelft.nl/uuid:d2a3c450-52ab-43ae-bad6-ba137911a0ba

https://doi.org/10.1016/j.watres.2019.05.100

0043-1354

Water Research, 161, 319-328

Institutional Repository

journal article

© 2019 R. Pallares Vega, Hetty Blaak, Rozemarijn van der Plaats, Ana M. de Roda Husman, Lucia Hernandez Leal, Mark C.M. van Loosdrecht, D.G. Weissbrodt, Heike Schmitt