FIG. 2.

Relatedness of the N. gonorrhoeae isolates (LG1 to LG26) used in this study. A composite of gels on which NheI-restricted genomic DNA from the 26 PIA Baltimore isolates was fractionated by PFGE is shown; normalization to a universal standard is described in Materials and Methods. A dendrogram that groups patterns into eight distinct clusters (A to H) based on the percentage of band similarity is also shown. Isolates that produced patterns that were <85% similar (see scale in the upper left corner) were considered different strains. Isolates of VR type PIA 1;2;1;1;1 belonged to four distinct PFGE patterns, which ranged from 90 to 96% similarity, while isolates of VR type PIA 1;1;1;1/4;1 fell into two clusters that showed 92 to 95% similarity.