What Pathogens Are Most Affected by the Colistin-Resistant mcr-1 Gene?

Prof. Andrea Endimiani, MD, PhD, from the Institute of Infectious Diseases at the University of Bern, Switzerland, explains which pathogens are most affected by the colistin resistant mcr-1 gene.

Interview Transcript (slightly modified for readability)

“The pathogens most affected by the spread of the mcr-1 gene, that is the gene that confers resistance to colistin, are, at the moment, Escherichia coli (E. coli), but there are also reports of other gram-negative bacteria that are important in human medicine like, Klebsiella pneumoniae.

We speculate, at the moment, that this gene is present in E. coli. E. coli is a pathogen that can be present in the intestinal tract of humans, [and] also animals and it can spread in the environment, and can also affect the food chain, [such as] the meat and the vegetables.

The mechanism of resistance is transferred to other pathogens via plasmids. Plasmids are DNA, small elements that are able to pass via conjugation. One pathogen that possesses this plasmid carrying the mcr-1 can conjugate with another one of the same species (ex: coli to coli), but also between different species (ex: coli to Klebsiella) and transfer this plasmid that carries the mcr-1, making the recipient that originally was not colistin-resistant, colistin resistant.”