Biofilm formation and invasive ability contribute to CC17 serotype Ⅲ group B Streptococcus virulence

To the Editor:Group B Streptococcus(GBS)colonizes the vagina and rectum of 7-30%of pregnant women and contributes to materno-neonatal invasive infections.To date,the pathogenesis of clinical GBS strains has remained elusive.Our previous study revealed that the clinical GBS isolates representing hypervirulent clonal complex 17(CC17)with enhanced invasiveness would disproportionately affect neonates and cause severe invasive diseases,including bacteriemia or meningitis,frequently than other strains of clonal complexes(CCs),for example,CC23.