Phylogenetic analysis of genome sequences for Neisseria meningitidis strains. With the exception of reference strain 053442 (serogroup C, sequence type 4821), all strains in groups I and II were sequenced in this study. The strain identification number, serogroup (in boldface), sequence type, and porin A type are shown for each sequence. Bootstrap values are listed at nodes. Black dots preceding identification numbers indicate strains isolated from patients. The dotted line between N. lactamica 020-06 and N. meningitidis represents a distance not to scale. The star indicates that the porin A gene was not detected by PCR or genome sequencing. Scale bar indicates amino acid substitutions per site.