Fig. 4: Differentiation of antibiotic resistance genes (ARGs) in influent sewage from two neighboring communities.

A ARGs that were unique to the university (U-) or community (C-) wastewater treatment plants (WWTPs) compared across all sampling dates from 2020 to 2022 (left), from 2022 only (center), and for the university WWTP for 2020–2021 vs 2022 (right). B Unique ARGs compared across all dates, indicated by antibiotic class. Total relative abundances were higher in the community WWTPs in 2020 and 2021 (Wilcox p < 0.0001). Samples were not collected at the university WWTP prior to October 2020. MLS indicates resistance to macrolide, lincosamide, and streptogramin.