When Hurricane Milton made landfall near Siesta Key, Florida, in early October 2024, the storm’s devastation was obvious: torn‑up pastures, flooded cattle ranches and poultry farms, and more than 19 tornadoes ripping through 5.7 million acres of agricultural land. While emergency crews focused on immediate rescue and recovery, scientists were already warning about a quieter, longer‑term danger – the spread of antibiotic‑resistance genes through flood‑laden runoff.
How storms move resistance genes
Chamteut Oh, an assistant professor of environmental microbiology at the University of Florida, has been studying microbes that live in soil and water. He explains that manure from livestock farms is rich in antibiotic‑resistance genes because many animals receive antibiotics both to treat illness and to prevent disease in crowded factory‑farm conditions. When these farms are flooded, the manure can be swept into rivers, creeks and coastal bays.
Oh’s team collected water samples along the Gulf Coast at 30 sites from one week to seven months after Milton. Their analysis showed a clear movement of resistance genes from inland bacteria to coastal environments. In some cases, the genes rode on particles such as microplastics and persisted for months, creating a reservoir of resistant microbes that could eventually infect people.
Public‑health implications
Antibiotic‑resistant infections claim 1.27 million lives worldwide each year, and more than 35,000 Americans die annually from such infections. When resistant bacteria enter drinking‑water supplies, standard treatment methods—like chlorination—can be overwhelmed by the sheer volume of floodwater, allowing untreated microbes to reach homes.
James Tiedje, a microbiologist at Michigan State University, warns that downstream communities relying on river water for drinking may face higher infection risks after severe storms. The problem is compounded by climate change, which is increasing both the frequency and intensity of hurricanes and droughts—each of which can amplify the spread of resistance genes.
Climate change and drought
Research presented in March 2026 linked drought conditions to higher antibiotic resistance in soil bacteria. As soil dries, natural antibiotics become more concentrated, killing off sensitive microbes and leaving behind a larger proportion of resistant strains. This finding underscores how extreme weather—whether flood or drought—can drive the evolution of resistant bacteria.
What can be done?
Oh stresses that the most effective prevention is reducing the overuse of antibiotics in agriculture. Limiting routine antibiotic use in healthy livestock would lower the amount of resistance genes entering the environment via manure.
State and local officials can also strengthen water‑treatment infrastructure to better handle surge volumes during storms, ensuring that floodwater does not bypass critical filtration and disinfection steps.
As the 2026 hurricane season ramps up, the connection between climate‑driven extreme weather and public‑health threats like antibiotic resistance becomes increasingly urgent. Communities near large animal‑production facilities should stay informed about water‑quality advisories and support policies that protect both the environment and family health.
Original reporting: KRDO (Colorado Springs metro) — read the source article.
