Molecular characterization of Streptococcus agalactiae from vaginal colonization and neonatal infections: a 4-year multicenter study in Greece.

A multicenter collection comprising of 171 Streptococcus agalactiae isolates from pregnant women recovered between 2007 and 2010 and 46 from unmatched neonates with invasive infections was subjected to antimicrobial susceptibility testing and genetic characterization. High rates of erythromycin resistance (20.47%) were observed only in isolates from pregnant women. ST1 was dominant in the vaginal colonization, whereas the hypervirulent ST-17 clone was detected in 67.39% of neonatal infections.