Antibiotic chemicals and antibiotic resistance genes enter the environment via wastewater effluents as well as from runoff from agricultural operations. The relative importance of these two sources, however, is largely unknown. The relationship between the concentrations of chemicals and genes requires exploration, for antibiotics in the environment may lead to development or retention of resistance genes by bacteria. The genes that confer resistance to metal toxicity may also be important in antibiotic resistance. In this work, concentrations of 19 antibiotics (using liquid chromatography tandem mass spectrometry), 14 metals (using inductively coupled plasma-mass spectrometry), and 45 metal, antibiotic, and antibiotic-resistance associated genes (using a multiplex, microfluidic quantitative polymerase chain reaction method) were measured in 13 sediment samples from two large rivers as well as along a spatial transect in a wastewater effluent-impacted lake. Nine of the antibiotics were detected in the rivers and 13 were detected in the lake. Sixteen different resistance genes were detected. The surrounding land use and proximity to wastewater treatment plants are important factors in the number and concentrations of antibiotics detected. Correlations among antibiotic chemical concentrations, metal concentrations, and resistance genes occur over short spatial scales in a lake but not over longer distances in major rivers. The observed correlations likely result from the chemicals and resistance genes arising from the same source, and differences in fate and transport over larger scales lead to loss of this relationship.
|Original language||English (US)|
|Number of pages||13|
|Journal||Environmental Science: Processes and Impacts|
|State||Published - Aug 2018|
Bibliographical noteFunding Information:
This work was funded by the Minnesota Environment and Natural Resources Trust fund as recommended by the Legislative and Citizen Commission on Minnesota Resources and a Doctoral Dissertation Fellowship from the University of Minnesota Graduate School. Thanks to Brock Matter, Xun Ming and Peter Villalta at the Masonic Cancer Center for their assistance with analytical method development, Rick Knurr for metal analysis of sediment samples at the Earth Science Geochemical Lab, Nic Jelinski for textural analysis of sediment samples, and Abby Kargol for her assistance with sediment extractions.
© The Royal Society of Chemistry.
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