The use of culture-independent tools to characterize bacteria in endo-tracheal aspirates from pre-term infants at risk of bronchopulmonary dysplasia

J Perinat Med. 2010 May;38(3):333-7. doi: 10.1515/jpm.2010.026.


Although premature infants are increasingly surviving the neonatal period, up to one-third develop bronchopulmonary dysplasia (BPD). Despite evidence that bacterial colonization of the neonatal respiratory tract by certain bacteria may be a risk factor in BPD development, little is known about the role these bacteria play. The aim of this study was to investigate the use of culture-independent molecular profiling methodologies to identify potential etiological agents in neonatal airway secretions. This study used terminal restriction fragment length polymorphism (T-RFLP) and clone sequence analyses to characterize bacterial species in endo-tracheal (ET) aspirates from eight intubated pre-term infants. A wide range of different bacteria was identified in the samples. Forty-seven T-RF band lengths were resolved in the sample set, with a range of 0-15 separate species in each patient. Clone sequence analyses confirmed the identity of individual species detected by T-RFLP. We speculate that the identification of known opportunistic pathogens including S. aureus, Enterobacter sp., Moraxella catarrhalis, Pseudomonas aeruginosa and Streptococcus sp., within the airways of pre-term infants, might be causally related to the subsequent development of BPD. Further, we suggest that culture-independent techniques, such as T-RFLP, hold important potential for the characterization of neonatal conditions, such as BPD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / genetics*
  • Bacteria / isolation & purification*
  • Bacterial Infections / complications
  • Bacterial Infections / microbiology
  • Bronchopulmonary Dysplasia / microbiology*
  • DNA, Bacterial / analysis
  • Enterobacter / genetics
  • Enterobacter / isolation & purification
  • Humans
  • Infant, Newborn
  • Infant, Premature*
  • Intubation, Intratracheal / adverse effects
  • Moraxella catarrhalis / genetics
  • Moraxella catarrhalis / isolation & purification
  • Polymorphism, Restriction Fragment Length
  • Pseudomonas aeruginosa / genetics
  • Pseudomonas aeruginosa / isolation & purification
  • RNA, Ribosomal, 16S / genetics
  • Risk Factors
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / isolation & purification
  • Streptococcus / genetics
  • Streptococcus / isolation & purification
  • Trachea / microbiology*


  • DNA, Bacterial
  • RNA, Ribosomal, 16S