Culture-Based Methods, Shotgun Sequencing Reveal Transmission of Bifidobacterium Strains From Mothers to Infants

For a study appearing in Nature Communications, researchers in Ireland use a combination of shotgun sequencing and cultivation-based methods to identify bacterial strains that are transferred from mother to infants. While previous studies had mainly relied only on shotgun sequencing, the usage of cultivation-based methods in this study highlighted several other strains that are transferred from the mothers to their babies. "We show that the use of a complementary culture-based approach reveals strains that are present at a level below the threshold at which detection through metagenomics alone was possible," the authors write. They analyzed microbes from 135 mother-infant dyads and confirmed the transmission of Bifidobacterium strains from mother to infant in early life. From mothers, the samples were collected from stool, breast milk, and the vagina and oral cavity, whereas the samples from infants came from stool. Usage of the culture-based methods was particularly essential for identifying bifidobacterial strains in breast milk. It was also found that external factors such as mode of delivery (vaginal or cesarean), spontaneous rupture of amniotic membranes, and avoidance of intrapartum antibiotics also influenced microbial transmission between mothers and infants. "The value of culture work to complement sequencing is very high and should be strongly considered for any future research in this area," the authors conclude.