Fig. 1

SNP parsimony phylogeny of 353 N. meningitidis isolates. Isolates are marked to indicate the serogroup (inner ring), year of isolation (second ring), whether collected in the USA (third ring), the body site from which they were isolated (outer ring), and whether the patient was a MSM (circles on branch tips). Counts in the key refer to isolates outside of the U.S. NmNG urethritis clade. The 209 isolates of the U.S. NmNG urethritis clade are collapsed, with details presented in Fig. 2. Additional labels identify the lineage 11 branch, the branches for sublineages 11.1 and 11.2, two European isolates from MSM that are closely related to U.S. isolates from MSM (asterisks), and two closely related NmNG urethritis isolates within sublineage 11.2 (blue star). The scale bar represents 250 substitutions within the 8607 core SNP alignment