PubMed · 2026-04-17
Irrigating crops with recycled wastewater spreads antibiotic-resistant bacteria and genes into soil, but plant roots appear to act as a natural filter, significantly reducing how much of that resistance makes it inside the plant.
Antibiotic resistance genes (sul1, ermB, intI1) rose significantly in soils irrigated with treated and raw wastewater, but these increases were not mirrored inside plant roots.
Root microbiomes were more resilient than soil microbiomes to wastewater irrigation, with most wastewater-associated bacterial groups absent or reduced in roots compared to surrounding soil.
One plant pathogen genus (Rhizorhapis) was promoted in roots under raw wastewater irrigation, indicating the root barrier is selective but not absolute.
