Heatwaves disrupt antibiotic resistance and soil functions in European study

A large-scale European study led by soil ecologist Franciska de Vries from the University of Amsterdam has revealed how extreme weather events impact the reservoir of antibiotics and resistance genes in soil.

Researchers tested soil samples from diverse regions, including Iceland, Sweden, Spain, and the Russian steppe, by exposing them to simulated extreme conditions such as severe drought, flooding, frost-thaw cycles, and intense heatwaves. The findings indicate that while drought, flooding, and frost-thaw cycles cause relatively mild and predictable changes to the resistance repertoire, heatwaves produce the most unpredictable and disruptive effects.

During intense heatwaves, soil bacteria appear to enter a survival mode. This state results in bacteria producing fewer antibiotics and exchanging fewer resistance genes. However, this shift comes at a cost to the ecosystem. The study noted that bacteria and fungi in cold, wet soils are more easily disrupted by heat and drought compared to those in warmer, drier climates. Such disruptions can impair critical soil functions, including CO2 sequestration.