Transmission of the major skin microbiota, Malassezia, from mother to neonate

Background: Skin surface colonization starts after birth. It is thought that early microbial colonization affects the development of skin immune functions. Although Malassezia is the predominant fungus in the skin microbiota in healthy individuals, the microorganism is associated with atopic dermatitis and seborrheic dermatitis. In the present study, transmission of skin microbiota from mothers to their neonates was elucidated using the Malassezia microbiota as an indicator.

Methods: Temporal changes in the level of Malassezia colonization of the skin from 27 neonates and mothers were investigated by real-time polymerase chain reaction assay. The genotypes of Malassezia colonizing the neonate and mother were also determined.

Results: Malassezia was detected from 89% and 100% of neonate samples on days 0 and 1 after birth, respectively. Subsequently, the level of Malassezia colonization of the neonates increased with time, whereas that of the mothers did not change. The Malassezia diversity of neonates shifted to the adult type by day 30. The genotype of Malassezia colonizing the skin of neonates agreed well with that of Malassezia colonizing the skin of the mothers.

Conclusion: Fungal microbiota colonization of neonates began on day 0, and the fungal microbiota of neonates had changed to the adult type by day 30. To our knowledge, this is the first report of a molecular analysis of the fungal microbiota of neonates.