FIG 1.

(A) Structure of plasmid pMCR-1-P3 carrying mcr-1 from Escherichia coli isolate P3. Colored rectangles represent open reading frames, with green, blue, orange, yellow, red, and gray rectangles representing replication genes, ORFs with known function, phage-related genes, mobile elements, the mcr-1 gene, and ORFs with unknown function, respectively. Individual rings range from 1 (outer ring) to 4 (inner ring): ring 1, genes encoded clockwise; ring 2, genes encoded anticlockwise; ring 3, GC content; ring 4, GC skew of the plasmid ([G−C]/[G+C]): magenta, >0; green, <0. Outer ring represents the high similarity of pMCR-1-P3 to LM996988 and CP016549, respectively. (B) Comparison of the immediate genetic environment of representative mcr-1-containing plasmids. Plasmid sequences were retrieved from GenBank; accession numbers are shown in brackets. Gray shading indicates >99% nucleotide identity.