Colistin works like a sledgehammer: it punches holes in the bacterial cell wall. The mcr-9 gene instructs the bacteria to add a chemical modification to their cell surface. This modification acts like a patch, making the surface less sticky to colistin. The result? The antibiotic bounces off. The scary headlines about mcr-1 were loud and clear. mcr-9, however, has been flying under the radar. Here is why that is dangerous:
But just when we started getting a handle on tracking mcr-1 , evolution threw us a curveball. Meet its stealthier, harder-to-detect cousin: . What is mcr-9? In the simplest terms, mcr-9 is a gene. It belongs to the mobilized colistin resistance (mcr) family. Like other members of this family (mcr-1 through mcr-8), its primary job is to protect bacteria from colistin. Colistin works like a sledgehammer: it punches holes
If you follow infectious disease news, you’ve probably heard of the "nightmare bacteria" or the "panic germ." For years, scientists have been sounding the alarm about a specific gene called mcr-1 . Why? Because it makes bacteria resistant to colistin —the antibiotic we hold in reserve as the "last resort" for multi-drug resistant infections. The result