Dynamics tracheal intubation airway microbiota of ventilated patients at continuous time points via metagenomic sequencing

Abstract Background: The use of an endotracheal tube may influence the tracheal microbiota compositions of ventilator patients which may be the leading cause of mortality in hospital intensive care units. Our primary objective is totrack the diversity and dynamics of bacterial communities within or between the patients, and to determine whether antibiotic therapy and adrenal corticosteroids treatment might influence the harbor of human bacterial pathogens.. Methods: The samples were obtained from eight patients of ventilator with endotracheal tube from Peking University People’s Hospital in Respiratory Intensive Care Unit (RICU) during a period of 15 days. The microbiota of tracheal aspirates samples from day0, 1, 3, 5,7,10 and 14 were analyzed using 454 pyrosequencing. The primers: 341F and 805R, complemented with 454 adapters and sample specific barcodes were used for PCR amplification of the 16S rRNA genes. Results: Analysis of 736,495 high-quality sequences (92,061 reads per patient) revealed a wide range of aerobic, anaerobic, pathogenic, opportunistic, novel and uncultivable bacterial species. The composition of microbiota species were significantly distinguished between the day0 and the day14 of tracheal aspirate samples (Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Streptococcus pneumoniae). On the individual basis, the microbiota was, however, relatively stable over time. Treatment with antibiotics and adrenal corticosteroids indeed influenced the global composition of the microbiota. CONCLUSION: These results support the phenomenon of dynamics diversification of airway microbiota in ventilated patients with tracheal intubation. Antibiotics and adrenal corticosteroids therapy may contribute to the alternation of microbiota.