title: Bacterial and Ureaplasma colonization of the airway: radiologic findings in infants with bronchopulmonary dysplasia.
abstract: OBJECTIVE
  We designed this retrospective study to compare radiologic findings in premature infants with bronchopulmonary dysplasia (BPD) in whom gram-positive cocci (GPC), gram-negative bacilli (GNB), or Ureaplasma urealyticum were colonized. Another objective was to correlate the radiologic findings of these patients with the clinical severity of BPD.
  
  
  METHODS
  We correlated serial tracheal aspirates with radiographic findings from 183 infants whose birth weight was < or = 1250 gm. BPD severity was assessed by oxygen dependency at 36 weeks of postconceptional age (36 w PCA) and at the time of discharge. Two radiologists independently scored films taken at birth and 1, 7, 14, 21, 28, and 35 days of life.
  
  
  RESULTS
  Of the study population, 55% were male and 35% were black; 80% received surfactant and 69% received dexamethasone; 91% survived. GPC isolates from throat cultures were mainly Staphylococcus [corrected] epidermidis and Streptococcus haemolyticus. A superimposed GNB colonization was present in 37% of these infants. Most common isolates were Klebsiella pneumoniae, Enterobacter cloacae, and Escherichia coli. Sepsis caused by GPC developed in 16% of all patients; 7% had sepsis caused by GNB. Infants infected with GNB remained receiving oxygen at 36 w PCA and at the time of discharge twice as often as those noninfected. RADIOLOGIC FINDINGS: Hyperinflation, interstitial changes, and generalized or localized emphysema were prominent features throughout. Mean radiologic scores increased over time in a pattern similar among GPC, GNB, and U. urealyticum infected and noninfected infants. High radiologic scores were not predictive at any time of infants who needed supplemental oxygen at 28 days and at 36 w PCA. Infants infected with U. urealyticum were neither clinically nor radiologically different than noncolonized neonates.
  
  
  CONCLUSIONS
  GPC, GNB, and U. urealyticum airway colonization is not associated with particular radiographic changes at any time. GNB-infected infants had the most severe BPD course, and yet they were radiologically indistinguishable from the other patients. U. urealyticum colonization does not result in more clinically severe BPD or demonstrate a unique radiologic course.
authors.affiliation: Department of Radiology, Ohio State University, College of Medicine, Columbus, USA.
authors.forename: L
authors.initials: L
authors.lastname: Cordero
authors.forename: B D
authors.initials: BD
authors.lastname: Coley
authors.forename: R L
authors.initials: RL
authors.lastname: Miller
authors.forename: C F
authors.initials: CF
authors.lastname: Mueller
mesh_terms: D001424:Bacterial Infections / Q000000981:diagnostic imaging* / Q000382:microbiology; D001997:Bronchopulmonary Dysplasia / Q000000981:diagnostic imaging* / Q000382:microbiology; D015169:Colony Count, Microbial; D005260:Female; D005865:Gestational Age; D006095:Gram-Positive Cocci / Q000254:growth & development* / Q000302:isolation & purification; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010614:Pharynx / Q000382:microbiology; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D016990:Ureaplasma urealyticum / Q000254:growth & development* / Q000302:isolation & purification