Antibiotic Residues In The Environment: Drivers Of Antimicrobial Resistance In Ecosystems—A Systematic Review

Introduction:

The widespread use of antibiotics in human medicine, agriculture, and aquaculture has resulted in the accumulation of antibiotic residues in environmental matrices such as soil, surface water, sediments, and wastewater. These residues act as environmental contaminants that exert selective pressure on microbial communities, thereby promoting the emergence and dissemination of antimicrobial resistance (AMR).

Methods:

A systematic literature review was conducted following PRISMA 2020 guidelines. Databases including Scopus, Web of Science, PubMed, and Google Scholar were searched for studies published in English between 2015 and 2025 using keywords such as “antibiotic residues,” “antimicrobial resistance,” “ARGs,” “soil,” “water,” “wastewater,” and “environment.” A total of 112 records were identified, and 35 studies met the inclusion criteria after screening.

Results:

Antibiotic residues were reported in 29 of the 35 studies, with concentrations ranging from 1 to 500 ng/L in aquatic environments and up to 1200 µg/kg in soils and sediments. Tetracyclines (24 studies), sulfonamides (21), fluoroquinolones (20), and macrolides (18) were the most frequently detected classes. Antimicrobial resistance genes (ARGs), particularly tet, sul, and bla, were identified in 23 studies, with significant positive correlations (r = 0.60–0.88) between antibiotic concentrations and ARG abundance. Major contamination sources included wastewater treatment plants (26 studies), agricultural runoff (19), aquaculture systems (14), and pharmaceutical effluents (11).

Conclusions:

Antibiotic residues are prevalent in environmental systems and contribute significantly to the spread of AMR. Strengthening environmental monitoring, improving waste management practices, and promoting responsible antibiotic use are important to mitigate resistance risks and protect ecosystem and public health.