Plants may be spreading superbugs to humans

Plant-based foods can transmit antibiotic resistance to the microbes living in our gut, a study has found.

Antibiotic-resistant infections are a threat to global public health, food safety and an economic burden.

To prevent these infections, it is critical to understand how these bacteria are transmitted.

“Our findings highlight the importance of tackling food-borne antibiotic-resistance from a food chain perspective, including plant-foods and meat,” said Marlene Maeusli, a PhD candidate at the University of Southern California.

Spread of antibiotic-resistant superbugs from plants to humans is different from outbreaks of diarrheal illnesses caused immediately after eating contaminated vegetables. Superbugs can asymptomatically hide in (colonise) the intestines for months or even years, and while escaping, cause an infection.

The researchers developed a novel, lettuce-mouse model system that does not cause immediate illness to mimic consumption of superbugs with plant-foods.

They grew lettuce, exposed it to antibiotic-resistant E. coli, and fed it to mice. Later, they analysed their faecal samples over a period of time.

“We found differences in the ability of bacteria to silently colonise the gut after ingestion, depending on a variety of host and bacterial factors,” said Mr. Maeusli.