“Last-resort” antibiotic beaten by resistant bugs globally.

New Scientist doesn’t usually hype the headline too much, so one gets concerned when they say that germs can now resist another “last-resort” antibiotic:

Bacteria carrying a gene that allows them to resist polymyxins, the antibiotics of last resort for some kinds of infection, have been found in Denmark and China, prompting a global search for the gene.

The discovery means that gram-negative bacteria, which cause common gut, urinary and blood infections in humans, can now become “pan-resistant”, with genes that defeat all antibiotics now available. That will make some infections incurable, unless new kinds of antibiotics are brought to market soon.

Colistin, the most common polymyxin, is a last-resort treatment for infections with bacteria such as E. coli and Klebsiella that resist all other available antibiotics.

In November, Yi-Yun Liu at South China Agricultural University in Guangzhou and colleagues discovered a gene for resistance to colistin in infected livestock, meat and humans. The mcr-1 gene can pass easily between bacteria, and the researchers predicted it could soon go global.

Unknown to them, it already had.