The effects of climate change on antibiotic resistance

The destructive force of the anthropocene

Right now, we are right within the Anthropocene — and make sure “our” planet feels it. Man-made climate change, plastic pollution, anthropogenically caused antibiotic resistance and the sealing of soils are just some of the examples that could make you think humans are testing the limits of the earth.

The consequences of our actions are getting more and more attention recently, especially since we experience the results of warming temperatures and the like firsthand. However, within the scientific community it has been clear for quite some while that greenhouse gas emission, urbanization, microplastic pollution and multi-resistant bacteria will change the world forever if we don’t act accordingly now.

And as misfortunes never come single: The phenomenons mentioned above are interfering with each other and build vicious cycle that is almost impossible to break.

While we are starting to feel the heat of climate change (like literally…), others enjoy the warmer temperatures. This includes some of the nastiest, sickening microorganisms.

Climate change and antibiotic resistance

Climate change itself seems to be challenging enough, as people and governments around the world only slowly seem to adapt their behavior. However, best case humanity capitulated at least an increase in temperature of 1,5 °C. The consequences of this “slight” worldwide temperature increase have been discussed by scientists and public media alike (here). Nevertheless, there is always something new to discover, as a recent publication earlier this year demonstrates. Here the authors state, that antibiotic resistance will emerge even faster because of climate change… hurray.

On one hand, this is supposed to happen because horizontal gene transfer — a major factor in the spread of antibiotic resistance — is happening more often and at a higher pace at warmer temperatures. On the other hand, it is long known, that microorganisms and especially pathogens replicate much faster at warmer temperatures. Sickening microorganisms are growing best at the temperature of the human body and therefore, bacteria will enjoy global warming. The icing on the top are reports of a direct correlation between increased temperatures and infection rates of human pathogens… hurray again!

For further information on risks and side effects: ask climate change

Climatic changes that our planet goes through and will go through in the future does not only lead to warmer temperatures globally but also to more extreme weather events. Apart from the direct impact of drought, flooding, and the likes, these weather extremes can also add to the spread of antibiotic resistance. Nitrogen fertilizers for example are known to enhance the spread and emergence of new antibiotic-resistant bacteria. Because of more flooding events, nitrogen fertilizer can be transmitted into remote areas and flowing waters, which could translocate resistant bacteria into new locations.

Furthermore, sanitization infrastructure — especially in emerging countries — could become victims of extreme weather events and as a consequence thereof, wastewater (a known source for antibiotic resistance) can be released into the environment.

Infectious disease on the rise?

Increasing temperatures will inevitably lead to a spread of infectious disease also into areas with moderate climate. Already today, an increase of ticks and mosquitos in central Europe can be observed and the number of these pathogen transmitting insects will only grow in the future. On the other hand, some areas of the world will have to fight with increased drought, which could lead to outbreaks of other infectious diseases. Mycobacterium tuberculosis, the bacterium that causes tuberculosis, is known to be less susceptible to antibiotics in a dry environment.

The combination of plastic pollution, antibiotic resistance, and climate change seem to be especially threatening. Microplastics are known to enhance the genetic exchange between bacteria and are already spread around the globe. If pathogens like Vibrio cholerae join these microbial communities, and increased temperatures enhance the horizontal gene transfer, we could soon be faced with dangerous sickening bacteria against which our weapons are blunt. When you add the spread of infectious bacteria around the globe due to warming temperatures to the equation, it becomes obvious that we are sitting on a powder keg. The combination of our actions will very likely drop back on us. In the example mentioned here, the drop back would come in the form of an almost untreatable cholera-pandemic.

What to take from it

Global processes are always interfering with each other. This also includes anthropogenically caused phenomenons. Therefore, we cannot look at things like climate change and antibiotic resistance isolated. As a consequence, to address these challenges we need to look at how they potentially enhance each other. Governments, scientists, and the public will be needed altogether to successfully overcome upcoming problems. As many of the discussed problems mesh, the world needs to work on several ends together to avoid being left behind and only treat symptoms instead of the actual cause.