Fig. 2. Collective cgMLST minimum spanning tree. Infant (labeled “Inf”) and healthcare worker (labeled “HCW”) isolates are numbered consecutively based on date of isolation of MRSA. Numbers next to lines show the number of allelic differences between isolates as determined by cgMLST. The line lengths have been shortened for better graphic display and are not proportional to the number of allelic differences. The angles between the lines are randomly determined. Background grey shading links isolates in the same group. PFGE group 1 is the same as WGS group 1, PFGE group 2 includes WGS group 2 and 3. USA isolates USA100, USA200, USA300, USA400, USA500, USA600, USA700, USA800, USA1000, and USA1100 were courtesy of Henry F. Chambers; USA isolates USA900 (ATCC BAA-1749) and USA1200 (ATCC BAA-1765) were obtained from the American Type Culture Collection.15 WGS groups 2 and 3 isolates are most closely related to USA100, WGS group 1 isolates are most closely related to USA300.
