'Superbug gene'

Antibiotic-Resistant Genes (ARGs) that were first detected in urban India. Scientists found them 8,000 miles away in one of the last ‘pristine’ places on earth. Soil samples taken in Svalbard have now confirmed the spread of blaNDM-1 into the High Arctic.

Worldwide spread of  blaNDM-1 and other antibiotic-resistant genes is a growing concern because they often target “last resort” classes of antibiotics, including Carbapenems. Carried in the gut of animals and people, the research team, say that blaNDM-1 and other medically-important ARGs were found in Arctic soils.

“Polar regions are among the last presumed pristine ecosystems on Earth. It provides a platform for characterizing pre-antibiotic era background resistance against which we could understand rates of progression of AR ‘pollution’,” says Professor Graham.”But less than three years after the first detection of the blaNDM-1 gene in the surface waters of urban India we are finding them thousands of miles away in an area where there has been minimal human impact.

Concern over the spread of Antibiotic-Resistant (AR) genes

Increasing antibiotic resistance is a global health crisis. An example is NDM-1, which is a protein that can confer resistance in a range of bacteria. NDM-1 was first identified in New Delhi and coded by the resistant gene blaNDM-1. Strains that carry blaNDM-1 were first found in clinical settings, but by 2010 blaNDM-1 was found. Since then, researchers found the resistant gene in over 100 countries, including new variants.
There are currently few antibiotics to combat bacteria that are resistant to Carbapenems — still a last-resort antibiotic class — and worldwide spread of blaNDM-1 and related ARGs is a concern.”What humans have done through excess use of antibiotics on global scales is accelerate the rate of evolution, creating a new world of resistant strains that never existed before,” explains Graham.

“Through the overuse of antibiotics, faecal releases and contamination of drinking water, we have consequentially speeded-up the rate at which superbugs might evolve.”For example, when researchers developed a new drug, natural bacteria can rapidly adapt and can become resistant; therefore very few new drugs are in the pipeline because it simply isn’t cost-effective to make them.”

Benchmark for tracking resistance

Published in the academic journal Environmental International, this latest research was carried out by an international team of experts from the Universities of Newcastle, York and Kansas and the Chinese Academy of Science in Xiamen.
Analysing the extracted DNA from forty soil cores at eight locations along Kongsfjorden, researchers detected a total of 131 ARGs. “The resistance genes detected, associated with nine major antibiotic classes, including aminoglycosides, macrolides and ?-lactams, used to treat many infections. As an example, researchers found a gene that confers the antibiotic-resistant genes, in Tuberculosis in all cores. Whereas scientists detected blaNDM-1 in more than 60% of the soil cores in the study.

“This finding has huge implications for global AR spread,” warns Graham. “A clinically important ARG originating from South Asia is clearly not ‘local’ to the Arctic.””Identifying an ARG ‘gradient’ across the study landscape, which varies as a function of human and wildlife impact. It shows there are Polar locations where ARG levels are so low they might provide nature’s baseline of antimicrobial resistance,” Graham says.

“The gradient of resistance genes closely reflects corresponding indicators of wastes in the geochemistry. Which suggests a novel basis for identifying sites for further AMR research” adds lead author, Dr Clare McCann.
“The only way we are going to win this fight is to understand all pathways that lead to antibiotic resistance. Clearly, the improvement of antibiotic stewardship in medicine and agriculture is crucial. But understanding how resistance transmission occurs through water and soils is also critical. We contend that improved waste management and water quality on a global scale is a key step.”