“Antibiotic resistance can be caused by small amounts of antibiotics”
“Antibiotic-resistant bacteria are a growing problem in health care globally. To prevent further development of resistance, it is important to understand where and how antibiotic resistance in bacteria arises. New research from Uppsala University shows that low concentrations of antibiotics can cause high antibiotic resistance to develop in bacteria.
In the present study, published in Nature Communications, the researchers have investigated how prolonged exposure to low levels of antibiotics contributes to the development of bacterial antibiotic resistance. During a course of antibiotics, a high proportion of the antibiotic dose is excreted in the urine in unchanged, active form, and can then spread into watercourses, lakes and soil in the wastewater. Consequently, these environments may contain low levels of antibiotics. In some parts of the world, large quantities of antibiotics are used in meat production and aquaculture, where small doses of antibiotics are added to the animal feed to make the animals grow faster. This means that the bacteria in their intestines are exposed to low levels of antibiotics over long periods, and these bacteria can then infect people via food.”