Environmental and Clinical Reservoirs of Antimicrobial Resistance: Implications for Genomic Surveillance and Infection Control

A recent study of environmental Escherichia coli from the Juan Díaz River and Panama City wastewater influent shows high rates of ribosome‑targeting antimicrobial resistance—shifting genomic‑surveillance and infection‑control priorities.

Investigators recovered isolates from the Juan Díaz River and influent at the Panama City wastewater treatment plant and analyzed them by PCR and whole‑genome sequencing to provide isolate‑level genomic context. Overall resistance frequencies were 80.8% for aminoglycosides, 37.4% for tetracycline, and 18.2% for chloramphenicol; plasmid‑associated resistance was more common in river isolates than in wastewater isolates.

Resistance was dominated by aminoglycoside, tetracycline, and chloramphenicol determinants. River isolates tended to carry plasmid‑mediated genes, whereas wastewater isolates more often harbored chromosomally integrated determinants. That contrast is consistent with pollutant‑driven selection in surface waters promoting plasmid mobility and horizontal gene transfer—implying higher short‑term dissemination risk from rivers—while chromosomal integration in wastewater suggests stabilized reservoirs with greater long‑term persistence.