Every year, about one million people die because germs no longer respond to medicines. Doctors call this problem antimicrobial resistance, or AMR.
We usually blame too many antibiotics for AMR. New research shows another culprit: a weedkiller called glyphosate.
What the Scientists Did
Researchers collected 68 bacteria from a protected wetland in Argentina. The wetland never used herbicides, but farms nearby do.
They also gathered 19 germs from hospitals and 15 from farms where herbicides are common. All 102 samples were tested against 16 antibiotics and against pure glyphosate and glyphosate‑based sprays.
What They Found
Hospital germs were highly resistant to many drugs. About three‑quarters could survive a strong antibiotic called carbapenem. The same hospital strains also survived high levels of glyphosate.
Every wild‑type strain from the wetland showed some ability to grow in glyphosate, even though the chemical was never applied there. One group, Enterobacter, grew in up to 80 mg per milliliter of glyphosate. In contrast, Bacillus stopped growing at just 2.5 mg per milliliter.
When the scientists built a family tree of all the bacteria, they saw that the most glyphosate‑tolerant bugs were closely related, no matter where they came from. This suggests the same genetic traits help them survive both herbicides and antibiotics.
Why It Matters
Glyphosate is the world’s most used herbicide. It is also listed by the International Agency for Research on Cancer as a probable human carcinogen and is known to harm bees.
Several European nations have already limited its use. France, Belgium and the Netherlands ban it for home gardens, and Germany keeps it out of public places.
The new study says regulators should test pesticides for their ability to pick out antibiotic‑resistant bacteria before they are sold. Labels might need warnings that resistant genes can move from treated soils to hospitals through water.