Croatian ‘Superbug River’ Puts Pharma Pollution Under the Microscope

"I felt like I was doing some kind of police work," she said, recalling the hours crouched in the mud by Croatia's largest river, scooping sludge into sample bottles, during a year of fieldwork in 2016.

Udikovic Kolic, head of the Laboratory for Environmental Microbiology and Biotechnology at the state-run Rudjer Boskovic Institute in Zagreb, documented alarming levels of two common antibiotics: azithromycin and erythromycin.

Worse, her team showed that the antibiotics were causing bacteria in the sediment to develop antimicrobial resistance, or AMR.

In plain terms, the sludge had become a cradle of superbugs — microbes immune to the drugs designed to destroy them.

Scientists have long warned of the rise of superbugs as a dire threat to human health.

"Antimicrobial resistance is one of the most concerning issues we have, similar to climate change," said Johan Bengtsson-Palme, an AMR expert at Sweden's University of Gothenburg.

"It's one of those things that could totally change the course of humanity in the next hundred years."

Antimicrobial resistance is one of the most concerning issues we have, similar to climate change. It's one of those things that could totally change the course of humanity in the next hundred years.

- Johan Bengtsson-Palme, University of Gothenburg

It is no secret that the world's rivers are awash with antibiotics, sloshed into waterways as hospital effluents or flushed from our bodies into urban sewage systems.

But scientists are still getting to grips with the genetic processes that spawn superbugs, and the Rudjer Boskovic Institute research helped fill in some gaps.

It also raised an unsettling question.

Readings by Udikovic Kolic and her...