Dissemination of the mcr-1 colistin resistance gene

Since our first report on plasmid-mediated colistin resistance gene mcr-1,1 strains previously collected in seven countries (Denmark, the Netherlands, Laos, Nigeria, Thailand, France, and the UK) have been found to carry mcr-1.2-6 Furthermore, the sequences in GenBank show that mcr-1 might also be circulating in Portugal and Malaysia. Interestingly, the sequence of pHNSHP45-2 is also almost identical to the partial sequence of a salmonalla Sal25 plasmid (GenBank accession number LFCC01000022) carrying mcr-1 from a food sample in Portugal. [...]IncHI2 plasmids carrying mcr-1 seem to have spread among different Enterobacteriaceae species and continents, which further suggests that food plays an important part in the spread of mcr-1 worldwide.