Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Neighbor joining tree of STEC O157 polymorphism-derived genotypes based on 138 tagging polymorphisms. Bullets represent bootstrap values equal to or greater than 80% (n = 1,000 bootstraps). Numbers in bold correspond to genotype numbers. Italicized numbers in parentheses represent clade frequencies in the human strains. Major lineages determined with full-length polymorphism–derived genotypes are denoted with Roman numerals. The scale bar represents substitutions per site.
