DEMONSTRATION OF MOTHER-TO-INFANT TRANSMISSION OF STAPHYLOCOCCUS-AUREUS BY PULSED-FIELD GEL-ELECTROPHORESIS

We assessed mother-to-infant transmission of Staphylococcus aureus. An terior nares swabs of 466 pregnant women, vaginal swabs of 305 of thes e women and anterior nares swabs of 305 6-day-old infants were examine d for the presence of S. aureus. The results showed that 7.5% of the v aginal swabs from the pregnant women and 10.1% of the anterior nares s wabs from the infants were positive for S. nca-eus. Six of the 466 pre gnant women (1.3%) and 12 of the 305 infants (3.9%) carried methicilli n-resistant S. aureus (MRSA) in the anterior nares site, but none of t he vaginal specimens were positive for MRSA. Analysis of SmaI digested chromosomal DNA analysis using pulsed-field gel electrophoresis (PFGE ) showed that methicillin-sensitive S. aureus (MSSA) strains obtained from four pairs of pregnant women and their infants were completely id entical, which strongly suggesting mother-to-infant transmission of S. aureus. Conclusion This study elucidated the. prevalence of S. aureus carriage among pregnant women and new-born infants. Mother-to-infant infection of S. aureus was demonstrated phenotypically and genetically . PFGE is a useful tool to det tectinfecfion routes including mother-t o-infant-infection.