A recent study published in the journal Nature Microbiology found that when soil dries out, it can speed up the natural processes that create and spread antibiotic resistance. This doesn’t mean drought directly creates superbugs in hospitals, but it suggests climate change could make the problem worse.
This matters a lot for the UK. The Met Office predicts that summers will get hotter and drier, with longer droughts if emissions stay high. Meanwhile, the NHS is already struggling with antibiotic-resistant infections, which are harder to treat and keep patients in hospital longer. When standard antibiotics stop working, doctors are sometimes forced to use powerful alternatives that are kept in reserve precisely because overusing them risks making those resistant too. These are known as “drugs of last resort”.
So what’s actually happening in the soil? Soil is teeming with bacteria, and many of them naturally produce antibiotics to kill off rivals. Other bacteria carry genes that make them resistant to those attacks.
An arms race in the soil
In normal, moist soil, bacteria live in a relatively stable environment. But when soil dries out, water gets squeezed into tiny, isolated pockets. Bacteria get crowded together, nutrients become scarce and competition turns brutal. In these conditions, bacteria produce more antibiotics to attack each other, and more resistance genes emerge to help them survive. It’s an arms race fuelled by drought.
Here’s why that’s relevant to human health: bacteria can swap genes with each other through a process called horizontal gene transfer – think of it like sharing a video game cheat code. This means resistance genes from soil bacteria can be picked up by bacteria that infect humans. In fact, some resistance genes found in soil bacteria have already been spotted in bacteria that infect people, hinting at a long evolutionary connection between the two.
Horizontal gene transfer explained.