We studied Ureaplasma urealyticum colonization in 93 intubated infants
(gestational ages 23-40 weeks) in our neonatal intensive care unit by
obtaining cultures from endotracheal aspirate and nasopharynx during
their first week of life. Eighteen infants had positive cultures, givi
ng a colonization rate of 19%. No infant more than 30 weeks' gestation
had a positive culture. The infants with positive cultures had a sign
ificantly lower gestational age and birth weight (p < 0.009 and p < 0.
005), with a colonization rate of 33% in infants less than 1000 g. Amo
ng the infants with positive cultures, 10 of 17 developed chronic lung
disease in contrast with 21 of 72 infants with negative cultures. The
development of chronic lung disease and duration of oxygen requiremen
t was strongly associated with immaturity but only weakly with Ureapla
sma urealyticum.