Superbug genes that were first detected in New Delhi over ten years ago have now spread to the Arctic -- one of the last 'pristine' places on the Earth, scientists say.
Antibiotic-Resistant Genes (ARGs) provide multidrug resistance (MDR) in microorganisms. 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 in 2008, but by 2010 blaNDM-1 was found in surface waters in Delhi.
Since then, the resistant gene has been found in over 100 countries, including new variants.
Analysing the extracted DNA from forty soil cores at eight locations along the Kongsfjorden region of Svalbard, a total of 131 ARGs were detected, according to the study published in the journal Environmental International.
Carried in the gut of animals and people, blaNDM-1 and other medically-important ARGs were found in Arctic soils that were likely spread in the faecal matter of birds, other wildlife and human visitors to the area.
"Polar regions are among the last presumed pristine ecosystems on Earth, providing a platform for characterising pre-antibiotic era background resistance against which we could understand rates of progression of AR 'pollution'," said David Graham, a professor at Newcastle University in the UK.
"Encroachment into areas like the Arctic reinforces how rapid and far-reaching the spread of antibiotic resistance has become, confirming solutions to AR must be viewed in global rather than just local terms," Graham said.
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," said Graham.
"A gene that confers MDR in tuberculosis was found in all cores, whereas blaNDM-1 was detected in more than 60 per cent of the soil cores in the study," he said.