title: 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 <33 weeks. All positive samples were speciated and serovars were determined by real-time PCR.
  
  
  RESULTS
  A total of 51 (37.5%) infants were 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 <26 weeks compared with 31% infants ≥ 26 weeks were culture or PCR positive. 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.
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Tae-Jung
authors.initials: TJ
authors.lastname: Sung
authors.forename: Li
authors.initials: L
authors.lastname: Xiao
authors.forename: Lynn
authors.initials: L
authors.lastname: Duffy
authors.forename: Ken B
authors.initials: KB
authors.lastname: Waites
authors.forename: Kirsty L
authors.initials: KL
authors.lastname: Chesko
authors.forename: Rose M
authors.initials: RM
authors.lastname: Viscardi
mesh_terms: D015373:Bacterial Typing Techniques; D012634:Bodily Secretions / Q000382:microbiology*; D001997:Bronchopulmonary Dysplasia / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D047928:Premature Birth; D015995:Prevalence; D012137:Respiratory System / Q000382:microbiology*; D012703:Serotyping; D016869:Ureaplasma Infections / Q000150:complications* / Q000453:epidemiology / Q000382:microbiology*; D016990:Ureaplasma urealyticum / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*