Abstract
At least one pilus island, PI-1 (70%), PI-2a (79%), or PI-2b (21%), was found among 898 Streptococcus agalactiae (group B streptococcus [GBS]) isolates recovered from humans, supporting the use of pilus proteins in vaccines. The stability and dominance of PI-1 and PI-2a in multiple serotypes and founder multilocus sequence types disseminated worldwide suggest it could be the PI combination present in ancestral GBS human pathogens.