Plasmid-mediated colistin resistance (mcr-1 gene): three months later, the story unfolds – editorial in Eurosurveillance


​The editorial published yesterday in Eurosurveillance highlights the current situation on the spread of plasmid-mediated colistin resistance gene (mcr-1). It also summarises available data from previously published articles and raises awareness about yet another threat to patient safety.

The evidence accumulated over the past months shows that the mcr-1 gene has spread to several continents and that it has been found in bacteria isolated from food animals, from the environment, from meat and vegetables, and from infected patients and human carriers without symptoms. Furthermore, the authors say that the gene, which is highly transferrable, has also been found in various bacterial species, and several different plasmids.
In humans, colistin is used, for example, for the treatment of patients infected with highly resistant bacteria such as carbapenem-resistant Enterobacteriaceae and Acinetobacter spp. for which different treatment options are limited. With the appearance of the mcr-1 gene, and an increasing consumption of colistin both in human and veterinary medicine, outbreaks of Enterobacteriaceae, that are resistant to both carbapenems and colistin may become more frequent.
The editorial makes a point that hospitals, in Europe and elsewhere, should be more aware of this new threat and consider a few practical and proportionate preparedness options that should help prevent the spread of mcr-1-positive Enterobacteriaceae in healthcare.