Figure 4. . . Minimum spanning tree showing the relationship between multilocus sequence types of 33 Haemophilus influenzae serotype e (Hie, red) and 99 Hif (green) strains isolated from patients in England and Wales, 2009–2010. The tree was derived from the 7 multilocus sequence type alleles of each isolate; the number within each circle represents a unique sequence type, and the size of the circle illustrates the proportion of strains with that sequence type (the smallest circle represents 1 isolate). Thick lines, thin lines, and dotted lines separating circles indicate single-, double-, and triple-locus variants, respectively.