The association between the microbes in the tracheobronchial
Bronchopulmonary dysplasia (BPD) is a chronic respiratory condition affecting >25% of infants with birth weights less than 1500 g, and is considered to be related to prematurity, inflammation, oxygen toxicity, infection and airway reactivity. The study aimed to evaluate the association between microbes in the lower respiratory tract (LRT) and the risk for severe bronchopulmonary dysplasia (sBPD) in premature infants.

A study was conducted infants who were admitted to the neonatal intensive care unit (NICU). The microbes in the LRT were screened by using tracheobronchial aspirate fluid (TAF) culture. One hundred and fifty-five infants were included in the analysis. Among 155 infants, 41 were diagnosed with sBPD, and 114 were diagnosed without sBPD. There were significant differences between infants with and without sBPD in regard to birth weight (BW), gestational age (GA), the duration of endotracheal ventilation and supplemental oxygen. The incidence of retinopathy (ROP) and sepsis was higher in the sBPD infants than in the infants without sBPD. There was a difference in the detection rate of Gram-negative bacteria (GNB) between the two groups. Stenotrophomonas maltophilia and Klebsiella pneumoniae were mainly detected in TAF.

In summary, the present study found that microbes of the LRT differed between infants with and without sBPD. Stenotrophomonas maltophilia and Klebsiella pneumoniae are more likely to be detected in sBPD infants. These bacteria may play an important role in the pathogenesis of sBPD. There might be relationships among the management of invasive ventilation, BPD and the presence of these microbes. Taking effective measures to shorten invasive mechanical ventilation duration may reduce GNB colonization and the severity of BPD. Further studies are necessary to evaluate the effects of GNB in the LRT of extremely premature infants at risk of sBPD.

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