Abstract
Patients with respiratory disease are usually provided with endotracheal tube due to respiratory obstacle. Many studies show that they are risky to be infected by ventilator associated pneumonia (VAP). VAP may cause death results from the invasion of the lower respiratory tract and lung parenchyma by microorganisms (virus, bacteria, or fungi). It is difficult for researchers to find out what microorganisms lead to VAP because some of the microorganisms are culture independent. This study analyzed 5 patients who were intubated in ICU. The data are genetic sequence counts from 16S rDNA which can be matched with bacteria species information. This study provides data vidualizrions and adopts the negative binomial regression model to understand the variation of bacteria counts during intubation and inferred the pathogenic bacteria at VAP.According to the bar plots, Proteobacteria and Tenericutes increased after intubation at several parts of the samples. Firmicutes all decreased after intubation and their effects were all significantly negative as well.