Concern is growing over a newly discovered superbug gene that could hail the beginning of a post-antibiotic era.
Housed in an E.coli strain in China, the mcr-1 gene was shown to make bacteria resistant against polymyxins - a class of antibiotics typically used as a last line of defence against deadly diseases.
Worryingly, the gene can be transferred between strains of bacteria and was found in both humans and animals.
Commenting on the significance of these finding Professor Timothy Walsh told the BBC: "All the key players are now in place to make the post-antibiotic world a reality.
"If MRC-1 becomes global, which is a case of when not if, and the gene aligns itself with other antibiotic resistance genes, which is inevitable, then we will have very likely reached the start of the post-antibiotic era.
"At that point if a patient is seriously ill, say with E. coli, then there is virtually nothing you can do."
The study was published in the Lancet journal.
Lead researcher Professor Jian-Hua Liu explained the findings toSky News: "These are extremely worrying results which reveal the emergence of the first polymyxin resistance gene that is readily passed between common bacteria, suggesting the progression to pan-drug resistance is inevitable."
In 2014, a report from the World Health Organisation (WHO), highlighted the need to address the growing strains of antibiotic resistant microorganisms.
"Without urgent, coordinated action," WHO stated, "the world is heading towards a post-antibiotic era, in which common infections and minor injuries, which have been treatable for decades, can once again kill."