Scientists have discovered a bacteria mutation that is resistant to an antibiotic, colistin, that is administered against virulent strains of E. coli and pneumonia, Huffington Post reports.

The colistin-resistant bacteria were found on a Chinese pig farm. The scientists later discovered the resistant bacteria in raw meat and humans.

The report was published Thursday in The Lancet Infectious Diseases, a U.K.-based medical journal.

China's Ministry of Science and Technology and the National Natural Science Foundation of China funded the study.

"The links between agricultural use of colistin, colistin resistance in slaughtered animals, colistin resistance in food, and colistin resistance in human beings are now complete," the researchers wrote.

The half a century old drug, Colistin, is administered to people only when all other antibiotics have proven ineffective. 

The resistant mutation, dubbed the MCR-1 gene, was found in one-fifth of the 804 animals observed, in 15 percent of the 523 raw meat samples and in 1 percent of the 1,332 patients observed in the study that lasted for around three years.

"One of the few solutions to uncoupling these connections is limitation or cessation of colistin use in agriculture," two of the authors wrote in published comments attached to the study.

"Failure to do so will create a public health problem of major dimensions."

Colistin is still commonly given to livestock around the world to treat or prevent diseases, even though the use of the antibiotics in humans is now controlled.

"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 ear",

University of Cardiff professor Timothy Walsh, one of the study's researchers, told the BBC on Thursday.