Low antibiotic concentration in the environment enough to increase antimicrobial resistance in laboratory conditions

September 5, 2018, University of Helsinki
Credit: CC0 Public Domain

Microbial communities are equipped with effective defence mechanisms against antibiotics. Existing antimicrobial resistance may become increasingly prevalent on its own – with no interference from antibiotics – in compact bacterial communities known as biofilms, or when protozoa hunt bacteria for food.

Increased antimicrobial resistance in has caused a global crisis in human health care. Strains of pathogenic bacteria resistant to all known have been found. Antimicrobial resistance is a trait that can spread within a bacterial species or even across the species barrier. Resistance will expand and become increasingly prevalent when bacteria that survive in an environment containing antibiotics genetically pass on or otherwise distribute this trait to other bacteria.

Recent studies indicate that even weak antibiotic concentrations are sufficient to cause a rise in the prevalence of antimicrobial resistance in cultured in laboratory conditions. Such conditions are brought about when antibiotics used to treat both human and animal infections end up in sewage or elsewhere in the environment.

"However, it should be noted that in natural conditions bacteria are a part of multispecies communities and exist in interaction with viruses and protozoa that hunt for bacteria. That's why the matter requires more study," says Johannes Cairns, who defended his dissertation at the Faculty of Agriculture and Forestry, University of Helsinki, Finland.

Low antibiotic concentrations increased antimicrobial resistance in laboratory-cultured equally well if not better compared to single species settings. Surprisingly, no antibiotics at all were necessary to see a rise in the prevalence of antimicrobial resistance.

"We found that can also become more prevalent due to the presence of protozoa that prey on bacteria or in conditions where the bacteria had settled on a surface as a biofilm, or a compact community," notes Cairns.

Explore further: New approach needed in the fight against superbugs

More information: Cairns, Johannes. Low antibiotic concentrations and resistance in microbial communities. Dissertation, University of Helsinki, Faculty of Agriculture and Forestry, Department of Microbiology. URN:ISBN:978-951-51-4371-6, hdl.handle.net/10138/237141

Related Stories

New approach needed in the fight against superbugs

September 3, 2018

An international research team, led by Professor Peter Collignon from The Australian National University (ANU) Medical School, has found we need to take a much broader approach than simply focusing on antibiotic usage, when ...

Recommended for you

When does one of the central ideas in economics work?

February 20, 2019

The concept of equilibrium is one of the most central ideas in economics. It is one of the core assumptions in the vast majority of economic models, including models used by policymakers on issues ranging from monetary policy ...

Research reveals why the zebra got its stripes

February 20, 2019

Why do zebras have stripes? A study published in PLOS ONE today takes us another step closer to answering this puzzling question and to understanding how stripes actually work.

Physicists 'flash-freeze' crystal of 150 ions

February 20, 2019

Physicists at the National Institute of Standards and Technology (NIST) have "flash-frozen" a flat crystal of 150 beryllium ions (electrically charged atoms), opening new possibilities for simulating magnetism at the quantum ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.