Demonstration of mother-to-infant transmission of Staphylococcus aureus by pulsed-field gel electrophoresis.
We assessed mother-to-infant transmission of Staphylococcus aureus. Anterior nares swabs of 466 pregnant women, vaginal swabs of 305 of these women and anterior nares swabs of 305 6-day-old infants were examined for the presence of S. aureus. The results showed that 7.5% of the vaginal swabs from the pregnant women and 10.1% of the anterior nares swabs from the infants were positive for S. aureus. Six of the 466 pregnant women (1.3%) and 12 of the 305 infants (3.9%) carried methicillin-resistant S. aureus (MRSA) in the anterior nares site, but none of the 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 identical, which strongly suggests [correction of suggesting] mother-to-infant transmission of S. aureus.


CONCLUSIONS
This study elucidated the prevalence of S. aureus carriage among pregnant women and newborn infants. Mother-to-infant infection of S. aureus was demonstrated phenotypically and genetically. PFGE is a useful tool to detect infection routes including mother-to-infant infection.
Mitsuda
T
T
Department of Paediatrics, Yokohama City University School of Medicine, Japan.
Arai
K
K
Fujita
S
S
Yokota
S
S
D001427:Bacterial Toxins; D001431:Bacteriological Techniques; D002353:Carrier State / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D004768:Enterotoxins / Q000032:analysis; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008826:Microbial Sensitivity Tests; D009297:Nasal Mucosa / Q000382:microbiology; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D013203:Staphylococcal Infections / Q000382:microbiology / Q000635:transmission*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D018089:Superantigens; D014621:Vagina / Q000382:microbiology
D001427:Bacterial Toxins; D004768:Enterotoxins; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal