The impact of metal pipe materials, corrosion products, and corrosion inhibitors on antibiotic resistance in drinking water distribution systems.

Drinking water distribution systems (DWDS) are unique engineering environments that are important routes for the acquisition and dissemination of antibiotic resistance. Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in drinking water pose risks to human and environmental health. Metals are known stressors that can select for antibiotic resistance. The objective of this review was to assess the state of knowledge regarding the impact of metal pipe materials, corrosion products, and corrosion inhibitors on the prevalence of antibiotic resistance in DWDS. ARGs and mobile genetic elements (MGEs) have been detected in full-scale DWDS in concentrations ranging from ~ 101 to 1010 copies/L. Metal pipe materials can select for bacteria harboring ARGs and metal resistance genes (MRGs) through co-selection processes. Corrosion products that develop in metal drinking water pipes (Cu, Fe, and Pb oxides) may also stimulate antibiotic resistance selection during distribution. Different corrosion inhibitor regimes (phosphates, sodium silicates) may also have impacts on microbial communities and the abundance of resistance genes in DWDS. Research is needed to quantify how engineering decisions related to drinking water infrastructure and corrosion inhibitor practices impact the abundance and distribution of ARG, MRGs, and MGEs in potable water systems. KEY POINTS: • Lack of quantitative measurements of antibiotic and metal resistance genes in drinking water distribution systems. • Pipe materials and corrosion products that develop in pipe scales may impact antibiotic resistance. • Corrosion inhibitors with zinc or phosphate could alter antibiotic resistance. • Management decisions should consider antibiotic resistance ramifications. Graphical abstract.