New Superbug Resistant To All Antibiotics Now Found Worldwide

Last week, I shared scary news of a new gene called mcr-1 conferring resistance to our last-ditch antibiotic, colistin. The gene was found in China with spread to the Netherlands. I raised concerns, too, about imports of some foods from China. Several new reports in the Lancet Infectious Diseases suggest the spread of this newly found resistance gene, mcr-1, is far worse than it initially appeared. Here are the latest findings from several just-released studies.

Chickens in a rearing shed-Credit Wikimedia

In some ways the most disturbing to me was the part of the “COMBAT” study that looked at how often Dutch travelers picked up the highly resistant superbug ESBL (that I’ve written about here). Researchers took stool samples from 2,001 travelers before and after their trips. Disturbingly, they found that 34% of the travelers acquired ESBL-producing Enterobacteriaceae after trips of 1-6 weeks’ duration. Nine of these travelers had a colistin-resistant ESBL isolate, and the mcr-1 resistance gene was found in six of the nine. (Resistance in the others occurred by different mechanisms).

Interestingly, 5/6 had developed traveler’s diarrhea; none had taken any antibiotics. These unrelated travelers had apparently acquired their resistant genes during visits to Peru, Bolivia, China, Tunisia, and SE Asia, suggesting that the mcr-1 colistin resistance gene has been circulating for some time, undetected...