| Description |
Wastewater treatment plants are among the primary sources of antibiotic-resistant bacteria and antibiotic-resistance genes released into the natural environment as a consequence of human activity. While the treatment of wastewater usually results in substantially reduced concentrations of antibiotics and other pharmaceuticals and can eliminate a significant portion of the resistant bacteria present in untreated wastewater, some resistance determinants will inevitably survive treatment to be released into receiving bodies of water. While a number of studies have investigated antibiotic resistance in wastewater treatment plants and treated effluent, few studies have attempted to address their impact on receiving rivers and streams. Here we used high throughput, deep metagenomics sequencing to investigate not only the impact of wastewater treatment plant effluent on the resistome of an urban watershed but also the fate of effluent-associated antibiotic resistance genes after release into the environment. Treated effluent was found to be associated with both increased abundance and diversity of antibiotic resistance gene types. The impact of wastewater discharge on the resistome of the bacterial communities diminished, however, with increasing distance from effluent discharge points. Our study highlights the role of human waste contamination on the spread of antibiotic resistance in river surface water but suggests that the impact may be limited, with little lasting influence on the watershed resistome. |
