Scientists find link between increases in local temperature and antibiotic resistance

May 21, 2018, Children's Hospital Boston
A representation of antibiotic resistance caused by climate change. Credit: Fawn Gracey/Boston Children's Hospital

Bacteria have long been thought to develop antibiotic resistance largely due to repeated exposure through over-prescribing. But could much bigger environmental pressures be at play?

Seeking to better understand the distribution of antibiotic resistance across the U.S., a multidisciplinary team of epidemiologists from Boston Children's Hospital and the University of Toronto have found that higher local temperatures and correlate with a higher degree of antibiotic resistance in common bacterial strains. The findings were published today in Nature Climate Change.

"The effects of climate are increasingly being recognized in a variety of infectious diseases, but so far as we know this is the first time it has been implicated in the distribution of antibiotic resistance over geographies," says the study's lead author, Derek MacFadden, MD, an infectious disease specialist and research fellow at Boston Children's Hospital. "We also found a signal that the associations between antibiotic resistance and temperature could be increasing over time."

"Estimates outside of our study have already told us that there will already be a drastic and deadly rise in antibiotic resistance in coming years," says the paper's co-senior author John Brownstein, Ph.D., who is Chief Innovation Officer and director of the Computational Epidemiology Group at Boston Children's and professor of pediatrics at Harvard Medical School (HMS). "But with our findings that could be compounding and accelerating an increase in antibiotic resistance, the future prospects could be significantly worse than previously thought."

During their study, the team assembled a large database of U.S. antibiotic resistance information related to E. coli, K. pneumoniae, and S. aureus, pulling from various streams of hospital, laboratory and disease surveillance data documented between 2013 and 2015. Altogether, their database comprised more than 1.6 million bacterial pathogens from 602 unique records across 223 facilities and 41 states.

Not surprisingly, when looking at antibiotic prescription rates across geographic areas, the team found that increased prescribing was associated with increased antibiotic resistance across all the pathogens that they investigated.

Then, comparing the database to latitude coordinates as well as mean and medium local temperatures, the team found that higher local average minimum temperatures correlated the strongest with antibiotic resistance. Local average minimum temperature increases of 10 degrees Celsius were found to be associated with 4.2, 2.2 and 3.6 percent increases in antibiotic resistant strains of E. coli, K. pneumoniae, and S. aureus, respectively.

More unsettling still, when looking at population density, the team found that an increase of 10,000 people per square mile was associated with three and six percent respective increases in antibiotic resistance in E. coli and K. pneumoniae, which are both Gram-negative species. In contrast, the antibiotic resistance of Gram-positive S. aureus did not appear to be significantly affected by population density.

"Population growth and increases in temperature and antibiotic resistance are three phenomena that we know are currently happening on our planet," says the study's co-senior author Mauricio Santillana, Ph.D., who is a faculty member in the Computational Health Informatics Program at Boston Children's and an assistant professor at HMS. "But until now, hypotheses about how these phenomena relate to each other have been sparse. We need to continue bringing multidisciplinary teams together to study antibiotic resistance in comparison to the backdrop of population and environmental changes."

MacFadden says the transmission factor is of particular interest for further scientific research.

"As transmission of antibiotic resistant organisms increases from one host to another, so does the opportunity for ongoing evolutionary selection of due to antibiotic use," MacFadden says. "We hypothesize that temperature and population density could act to facilitate transmission and thus increases in ."

"The bottom line is that our findings highlight a dire need to invest more research efforts into improving our understanding of the interconnectedness of infectious disease, medicine and our changing environment," Brownstein concludes.

Explore further: Antibiotic resistance can be caused by small amounts of antibiotics

More information: Antibiotic resistance increases with local temperature, Nature Climate Change (2018). nature.com/articles/doi:10.1038/s41558-018-0161-6

Related Stories

Antibiotic resistance—it's a social thing

March 15, 2016

Trace concentrations of antibiotic, such as those found in sewage outfalls, are enough to enable bacteria to keep antibiotic resistance, new research from the University of York has found. The concentrations are much lower ...

Recommended for you

Scientists solve mystery shrouding oldest animal fossils

March 25, 2019

Scientists from The Australian National University (ANU) have discovered that 558 million-year-old Dickinsonia fossils do not reveal all of the features of the earliest known animals, which potentially had mouths and guts.

Earth's deep mantle flows dynamically

March 25, 2019

As ancient ocean floors plunge over 1,000 km into the Earth's deep interior, they cause hot rock in the lower mantle to flow much more dynamically than previously thought, finds a new UCL-led study.

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.