Cover image

Infants are born nearly sterile and their microbiomes are established over the first months of life. For premature infants that receive antibiotics immediately after birth, colonization involves bacteria to which the infant is exposed while hospitalized in the neonatal intensive care unit. In this issue, a genome-resolved metagenomic study describes evidence that identical strains of bacteria colonize the skin, mouth, and gut. Given significant overlap across body sites, it is concluded that the premature infant microbe can exhibit overall very low microbial diversity. The cover depicts the exposure of a premature infant in an isolette to hospital room–derived microbes. (Cover illustration by Zosia Rostomian, Matthew Olm, and Jillian Banfield. [For details, see Olm et al., pp. 601–612.])