Figure 1. Dendrogram analysis of SmaI-digested pulsed-field gel electrophoresis fingerprints of 58 isolates of group B Streptococcus (GBS), serotype III, subtype 4 (fingerprints highlighted in red box and bracket) and of 324 randomly selected GBS isolates of different serotypes, Hong Kong, 1993–2012. The dotted vertical line on the serotype column delineates the pulsed-field gel electrophoresis clustering at 90% similarity, determined by analysis by dice coefficient with 1% tolerance and by the unweighted pair group method with arithmetic mean (BioNumerics version 7.0; Applied Maths, Sint-Martens-Latem, Belgium). On the source column, solid black indicates that the GBS strain was isolated from invasive sites; solid gray indicates that the strain was from noninvasive sites.