Frequency of Ureaplasma Serovars in Respiratory Secretions of Preterm Infants at Risk for Bronchopulmonary Dysplasia

Abstract

Objective: Ureaplasma respiratory tract colonization is associated with bronchopulmonary dysplasia (BPD) in preterm infants. Whether the 4 Ureaplasma parvum and 10 Ureaplasma urealyticum serovars differ in virulence is unknown. This study was conducted to determine the distribution of Ureaplasma serovars in respiratory secretions of a prospective cohort of preterm infants and to assess whether any of the serovars are associated with BPD. Methods: Serial endotracheal and/or nasopharyngeal aspirates were obtained for Ureaplasma culture and PCR from 136 infants of gestational age Ureaplasma-positive one or more times during the first month of life. Respiratory colonization was inversely related to gestational age. Sixty-five percent of infants U. parvum was more common (N = 32, 63%) than U. urealyticum (N = 17, 33%); both species were present in 2 samples. Serovars 3 and 6 alone and in combination accounted for 96% U. parvum isolates. U. urealyticum isolates were commonly a mixture of multiple serovars, with serovar 11 alone or combined with other serovars (10/17, 59%) being the most common serovar. No individual species or serovars or serovar mixtures were associated with moderate-to-severe BPD. Conclusions: U. parvum serovars 3 and 6 and U. urealyticum serovar 11 were the most common serovars detected in respiratory samples from a prospective cohort of preterm infants.