New bug in China overcomes last-resort antibiotic

China is harboring what could be a doomsday bug, according to scientists who issued an alert for a possible worldwide pandemic, according to reports by CBC News and Channel News Asia. The scare is even more serious because the resistant bacterium has been found in both animals and humans.

Using apocalyptic terms such as "a virtual return to the Dark Ages" and "a major breach in our last line of defense," a Chinese study in the journal Lancet Infectious Diseases said the formerly reliable antibiotic colistin has been shown ineffective against the newly evolved bug.

The study found the colistin-resistant strain in several hospital patients in China in addition to pigs and in other meat. Researchers said it is easily spread among strains, bypassing the usually longer resistance route of mutation.

Colistin belongs to the polymyxins class of antibiotics and until now has been considered an effective treatment against superbugs that normally develop in hospital settings. It often is referred to as the last resort treatment for such diseases.

Dr. Peter Lin

"When they found this gene popping up in China in the animals and in the meats that they were testing and also in the patients, now they're worried because now this germ is now strong against this last line. And so if we don't have another antibiotic to come in, what do we do then?" said Dr. Peter Lin, a family physician and medical commentator on CBC News Network.

The drug is particularly weak against the new gene, called MRC-1, when taken orally, and although it might be effective if injected, it would be powerful administered in that fashion, suggested one physician.

Liu Jian-Hua of the Southern Agricultural University in China and co-author of the study, said in a report by CBC News that the MRC-1 mutation was discovered in E. coli and pneumonia, common and deadly bacteria, making them invincible to treatment. When the gene was found in 16 of 1,322 hospital specimens, the scientists realized it had passed from animals to humans, a rare occurrence.

Although the MRC-1 gene is confined to China at the moment, other researchers fear it is just a matter of time until it spreads around the world, creating what one said would be the "post-antibiotic era" in which there no longer was a treatment for E. coli and other similar diseases.

Another suggested the first move is consideration of whether to limit colistin in animal husbandry and a recognition that the same antibiotics should not be used in animals and humans.

Scientists fear a repeat of the 2010 incident when the NDM-1 superbug gene developed in India and spread globally before it could be brought under control.

- here's the story from CBC News and another from Channel News Asia
- here's the link to the Lancet report