Study finds antimicrobial resistance in soils Scotland-wide

Plant in soil

Resistance to antibiotics has been found in the environment across Scotland, according to a new international study involving Strathclyde.

The study by scientists at the University, The James Hutton Institute in Aberdeen, the Institute of Urban Environment in Xiamen, China, and Newcastle University, is the first to test Scotland’s soils at a national level for antimicrobial resistance (AMR), where microbes like bacteria have evolved to resist antimicrobial drugs such as antibiotics, leading to superbugs like MRSA. 

The study, published in the Nature Group journal Communications Earth & Environment, was funded by UKRI’s Natural Environment Research Council. 

Antimicrobial resistance

It used soils in the National Soils Archive, which was created and is managed by the Hutton and contains soils dating from 1934 to the present, enabling scientists to “go back in time” to see how prevalence of things like AMR have changed.

Genes resistant to common antibiotics were found to be "ubiquitous” across all soils tested, including those from "relatively pristine” environments. This included microbes with genes resistant to “last-resort” antibiotics for multidrug-resistant infections, like vancomycin.

Principal investigator Dr Charles W. Knapp, a Reader in the Department of Civil & Environmental Engineering at Strathclyde, said:

This has been a unique opportunity to examine the National Soil Inventory of Scotland at Hutton.

“With over 200 locations and nearly 300 genes, we better understand how environmental conditions promote antimicrobial resistance abundance and diversity. More importantly, archives, as such, present a resource that can help elucidate epidemiological patterns by examining their genetic patterns in time and space, especially how they could be influenced by human impact.”

Resistant bacteria

Environmental microbiologist Dr Eulyn Pagaling  from the Hutton, said: “Antimicrobial resistance has been in the environment since before antibiotics were developed for humans, but its spread has been exacerbated by human and veterinary use, with a lot of the medicines we take going into the environment via sewage and slurry.

“There’s a concern that antimicrobial resistance genes can then spread to other bacteria in the environment. These resistant bacteria could then get back into humans and then clinical environments, through contact with the environment, water or food crops, for example, impacting the effectiveness of the antibiotics we rely on day-to-day.

“With our study, we now have a baseline for how widely antimicrobial resistance genes are spread across Scotland's soils. This means we could now look at how fast antimicrobial resistance is spreading over time and where.” In addition to this study, the Hutton is also looking ways AMR enters the environment, including through sewage and land use.

Social prescribing

As AMR is driven by the amount of pharmaceuticals entering the environment, the institute’s scientists are also collaborating with the Scotland One Health Breakthrough Partnership and the NHS to see whether alternatives to prescribing of antibiotics for human use could help to tackle this problem. This could be social prescribing, including going for a swim or taking a walk or prescribing of environmentally less harmful compounds.