Antibiotic resistance in urban stormwater: a review of the dissemination of resistance elements, their impact, and management opportunities

Abstract

The public health crisis of antibiotic resistance is a growing threat across the world that is only expected to intensify in the coming years. The cycling of antibiotic resistance genes (ARGs) in the environment via urban stormwater runoff is one means by which humans are exposed to resistant bacteria as traditional gray stormwater infrastructure facilitates the transport of resistance elements into water bodies utilized by the public. In this review, existing research on the occurrence of ARGs in urban stormwater runoff is critically reviewed with the goal of determining the role of stormwater in the dissemination and development of antibiotic resistance. From the research conducted, urban stormwater is concluded to be hotspot for antibiotic resistance due to the confluence of factors that contribute to an increase in the frequency of gene transfer including ARGs, antibiotic resistant bacteria, mobile genetic elements, and selective pressures such as metals. The long-term impact of ARG dissemination on downstream environments such as surface water bodies and green stormwater infrastructure (GSI) systems is also reviewed. GSI has the potential for ARG management within the urban water cycle while also presenting a threat for antibiotic resistance proliferation after collecting and possibly concentrating ARGs. More research is needed to understand how engineering decisions can be incorporated into GSI design to maximize the removal of ARGs from stormwater runoff while also minimizing ARG propagation and mobilization.