Late-onset neonatal group B streptococcal disease associated with breast milk transmission: molecular typing using RAPD-PCR.

Group B Streptococcus (GBS) is considered to be the major cause of neonatal sepsis and meningitis of bacterial origin. Late-onset GBS infection is infrequent and occurs between 1 week and 3 months of age. The transmission of GBS through the ingestion of breast milk is reported in the literature, but only a few of these cases have been confirmed by molecular techniques. In this article we report five cases of late-onset GBS disease: transmission through maternal milk was confirmed in four cases, using the random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) typing assay. In addition, the RAPD-PCR assay showed that each of the isolated clones belonged to a different RAPD genotype, thus revealing that the late-onset GBS infections were not epidemiologically related.