Figure 3.

Results of the sequencing of a transmissible antimicrobial resistance plasmid from a Salmonella enterica strain (Han et al., 2012). The plasmid contains multiple antimicrobial resistance (denoted in red) and heavy metal/disinfectant (denoted in yellow) resistance genes, including those carried in a Tn21 transposon. Within the Tn21 transposon, there was a class 1 integron carrying multiple antimicrobial resistance genes. This nesting of MGEs within other MGEs provides significant opportunities for the generation and dissemination of diverse antimicrobial resistance elements. AMR regions and mobile genetic elements also often have a higher G + C content compared to the plasmid backbone as is highlighted in the inner ring of the circular plasmid diagram (gold vs. purple bars).