DOI: 10.1128/mBio.01229-17
LETTER
We read with great interest the article in mBio regarding the discovery of a third colistin resistance determinant, mcr-3, in plasmid pWJ1 isolated from porcine Escherichia coli in China (1). This discovery and the subsequently reported discovery of a fourth colistin resistance determinant, mcr-4 (2), provide further support for our hypothesis that the mcr determinants (phosphoethanolamine transferases) may have primarily or simultaneously originated in aquatic environments as a result of aquacultural activities, including integrated aquaculture, that bring together aquatic and terrestrial bacteria (3).
The over 45 million metric tons of fish, crustaceans, and mollusks produced by aquaculture in China …
