Fig. 1
Epistasis between the mupirocin resistance-encoding mutation in the ileS gene and many other loci is associated with the toxicity of the USA300 lineage of MRSA. This heat map illustrates where specific combinations of the polymorphic site in the ileS gene and polymorphic sites elsewhere on the chromosome are associated with the toxicity of individual isolates. The mupR-conferring site is indicated on the x- and y-axes by the red arrows