The first sign for colistin resistance was found about four years ago at a pig farm near Shanghai. When the resistance in the lab proved to be transferable, further trials were carried out to samples of slaughter pigs from four provinces as well as of pork and poultry meat from tens of supermarkets as well as wet markets. In addition, samples were taken from those infected with the disease in hospitals.
In research discussed in the scientific medical journal The Lancet Infectious Diseases., a direct link has been established between the usage of the antibiotic in animal husbandry and the resistance found in slaughtered animals, in food and in humans. This resistance, caused by a new mutation dubbed the MCR-1 gene, would also be capable of spreading.
A large share of the animals (about 20%) as well as the meat (about 15%) turned out to carry resistant bacteria. The researchers predominantly worry about the resistance, as bacteria can exchange this amongst each other, but also in between species.
As a result of the research, the Chinese ministry of agriculture has decided to better monitor the usage of the antibiotic colistin. There is also evidence that the resistance might have spread to Laos and Malaysia, according to the BBC.
Prof Timothy Walsh, who collaborated on the study, from the University of Cardiff, told the BBC News website: “All the key players are now in place to make the post-antibiotic world a reality.
“If MCR-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.”