December 7, 2021

I, Science

The science magazine of Imperial College

Worrying news about a widely used last-resort antibiotic, as its overuse in agriculture is thought to have caused resistance gene to develop.

shutterstock_125648294It has recently emerged that a resistance gene for the most widely used ‘last resort’ antibiotic, colistin, has been found. Researchers from the South China Agricultural University revealed that the gene, MCR-1, was identified in meat samples and even more worryingly, in a small number of urine and blood samples taken from hospitals.

The researchers warn that this particular gene is not confined to one class of bacteria, allowing the resistance to spread and cause ‘pan-drug resistance’, as this gene is found on a plasmid; a circle of DNA which bacteria will share with one another. Once bacteria acquire the MCR-1 encoding plasmid, they will not get rid of it, making attempts at reducing the use of colistin fairly futile.

Colistin, one of the most regularly used of the ‘last resort’ class of antibiotics called polymyxin, is thought to have been overused in farming animals which scientists believe is what caused the resistance.

The news comes halfway through the World Antibiotic Awareness Week, highlighting the issue even more fervently. For resources on raising awareness on antibiotic resistance, click here.


Sarah Cowen-Rivers is studying for an MSc in Science Communication.

Image: Avarand (Shutterstock)