Molecular characterization of Chilean isolates of streptococcus agalactiae Caracterización molecular en aislados chilenos de Streptococcus agalactiae

Background: Streptococcus agalactiae is the main causing organism of invasive infections such as sepsis and meningitis in the newborn. Aim: To perform a genotype characterization of Streptococcus agalactiae strains coming form invasive infections of newborns and colonized pregnant women. Material and methods: A group of 58 strains not related epidemiologically, isolated from colonized pregnant women and invasive infections in newborns, were studied. Pulsed field electrophoresis (PFGE) and polymerase chain reaction amplification of hylB and IS1548 genes, as possible virulence markers, were performed. Results: Among the studied strains, 37 genetic subtypes were observed. There were nine groups of identical PFGE patterns. Three corresponded to serotype Ia and six to serotype III. An erythromycin and clindamycin resistant clone was identified in three colonized women and a newborn with sepsis, which were not epidemiologically related. The hylB gene was equally present in cases of neonata