Environmental pollution with antibiotics leads to resistance

More and more people are infected with antibiotic resistant bacteria. But how do bacteria become resistant? A recent doctoral thesis from the Centre for Antibiotic Resistance Research at University of Gothenburg has investigated the role of the environment in the development of antibiotic resistance.

“An important question we asked was how low concentrations of antibiotics that can favour the growth of resistant bacteria in the environment”, says Johan Bengtsson-Palme, author of the thesis.

“Based on our analyses, we propose emission limits for 111 antibiotics that should not be exceeded in order to avoid that environmental bacteria become more resistant.” 

A recent report, commissioned by the British Prime Minister David Cameron*, proposes that the emission limits suggested in Johan’s thesis should be used as a starting point to regulate antibiotic pollution from, for example, pharmaceutical production – globally.

“Many people are surprised that such regulations are not already in place, but today it is actually not a crime to discharge wastewater contaminated with large amounts of antibiotics, not even in Europe”, says Johan Bengtsson-Palme.

In one of the studies in the thesis, the researchers show that resistance genes against a vast range of antibiotics are enriched in an Indian lake polluted by dumping of wastewater from pharmaceutical production.

“It’s scary. Not only do the bacteria carry a multitude of resistance genes. They are also unusually well adapted to share those genes with other bacteria. If a disease-causing bacterium ends up in the lake, it may quickly pick up the genes it needs to become resistant. Since the lake is located close to residential areas, such spread of resistant bacteria to humans is not hard to imagine”, says Johan Bengtsson-Palme.

The thesis also shows that resistant bacteria spread in the intestines of travelers who have visited India or Central Africa, even if the travelers themselves have not become sick  

“That resistant bacteria spread so quickly across the planet highlights that we must adopt a global perspective on the resistance problem”, says Johan Bengtsson-Palme. “Furthermore, it is not enough to reduce the use of antibiotics in healthcare. We must also reduce the use of antibiotics for animals, and try to limit the releases of antibiotics into the environment to try to get control over the growing antibiotic resistance problem before it is too late”. 

The thesis ”Antibiotic resistance in the environment: a contribution from metagenomic studies” will be defended on a dissertation on May 26th.

Link to thesis: http://hdl.handle.net/2077/41843 

* Tackling drug-resistant infections globally: Final report and Recommendations. The review on antimicrobial resistance chaired by Jim O’Neill.
http://amr-review.org/Publications 

Facts

•  Disease-causing bacteria may pick up genes that make them resistant to antibiotics from other, harmless, bacteria
•  Many of the resistance genes that cause problems in healthcare today likely originate from harmless bacteria in the environment
•  How these genes go from there into disease-causing bacteria is still unclear
•  To understand and limit the spread of resistance genes from the environment is one of the goals of the recently formed interdisciplinary Centre for Antibiotic Resistance Research (CARe) at the University of Gothenburg (www.care.gu.se)

Contact:
Johan Bengtsson-Palme, doctoral student at the Sahlgrenska academy, University of Gothenburg
+46 733661598
johan.bengtsson-palme@gu.se 

Supervisor:
Joakim Larsson, professor in environmental pharmacology at the Sahlgrenska academy, University of Gothenburg, and director of CARe
+46 709-621068
joakim.larsson@fysiologi.gu.se 

Johanna Hillgren
Press officer
Sahlgrenska academy, University of Gothenburg
46 31-786 4029
46 766-18 4029
johanna.hillgren@gu.se

The Sahlgrenska Academy is the faculty of health sciences at the University of Gothenburg. Education and research are conducted within the fields of pharmacy, medicine, odontology and health care sciences. About 4,000 undergraduate students and 1,200 postgraduate students are enrolled at Sahlgrenska Academy. Around 1,400 people work at the Sahlgrenska Academy, 850 of them are researchers and/or teachers.

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