Nature reports:

The emergence of disease-causing bacteria that are resistant to antibiotics is often attributed to the overuse of antibiotics in people and livestock. But researchers have homed in on another potential driver of resistance: antidepressants. By studying bacteria grown in the laboratory, a team has now tracked how antidepressants can trigger drug resistance1.

“Even after a few days exposure, bacteria develop drug resistance, not only against one but multiple antibiotics,” says senior author Jianhua Guo, who works at the Australian Centre for Water and Environmental Biotechnology at the University of Queensland in Brisbane. This is both interesting and scary, he says.

Globally, antibiotic resistance is a significant public-health threat. An estimated 1.2 million people died as a direct result of it in 2019, and that number is predicted to climb.

Guo became interested in the possible contributions of non-antibiotic drugs to antibiotic resistance in 2014, after work by his lab found more antibiotic-resistance genes circulating in domestic wastewater samples than in samples of wastewater from hospitals, where antibiotic use is higher.

Guo’s group and other teams also observed that antidepressants — which are among the most widely prescribed medicines in the world — killed or stunted the growth of certain bacteria. They provoke “an SOS response”, Guo explains, triggering cellular defence mechanisms that, in turn, make the bacteria better able to survive subsequent antibiotic treatment. [Continue reading…]