Distribution Of Bacterial Community In Respiratory Tract Of Pulmonary Tuberculosis Patients

Objective: with more and more attentions that has been paid to the correlation between the changes of human microecology and human diseases,a great number of studies have shown that the occurrence and development of chronic respiratory diseases are closely related to the changes of respiratory microecology.Pulmonary tuberculosis is an infectivity disease with a very high incidence.China is one of the countries that a large number of people are easy to get tuberculosis,especially Yunnan province,southwest in China.In Yunnan,the drug resistance rate of tuberculosis increases daily.However,the research of new method for tuberculosis treatment lags relatively.By examining the changes of lower respiratory bacterial community in tuberculosis patients compared with that in healthy people,this thesis mainly discusses the relationship between lower respiratory microorganism and the occurrence and development of pulmonary tuberculosis.Moreover,this thesis could provide new ideas for the treatment of pulmonary tuberculosis.Method: the whole method is based on the application of high-throughput sequencing technology for bacterial 16 S r DNA V3-V4 variable region based on second-generation sequencing.I collect bronchial epithelial mucosa brush-off samples from 11 healthy volunteers and 20 pulmonary tuberculosis patients in Yunnan.Also,through the sequencing technology,I compare the results of lower respiratory microorganism from pulmonary tuberculosis patients and healthy people.Results: the experiment collects 40 specimens of bronchial epithelial mucosal biopsy brush off and pharyngeal swab from smear-positive pulmonary tuberculosis patients,and collects 55 specimens of bronchial epithelial mucosal biopsy brush off of 5 different lung segments from the healthy volunteers.After the high throughput sequencing,firstly,I find that the lower respiratory tract flora of my experiment is highly different from the same experiment of foreign studies.Base on the lower respiratory tract of healthy people in Yunnan,I find that there are lots of firmicutes microorganism and a little of proteobacteria microorganism in their lungs;also,for the family composition,the dominant colonizing bacteria are bacillus,lactococcus,enterococcus,and streptococcus.While,In the same foreign research reports as the method of collecting specimens,the main colonization bacteria in the pulmonary flora were as follows:pseudomonadaceae,burkholder and staphylococcidae.Secondly,I find that the bacterial flora in different parts of the lungs of healthy people in Yunnan is consistent with the foreign reports on the composition of the bacterial flora in the lungs of healthy people.My experiment shows that the number of bacteria in the lower respiratory tract of tuberculosis patients is more abundant than that of healthy people,among which firmicutes and bacteroidetes are dominant;also,at the genus level,the dominant bacteria are prevotella,veillonella.,Pseudomonas and Streptococcus.We found that the abundance of Mycobacterium tuberculosis complex in two samples increased significantly.Prevotella showed three genera with different proportion,but the overall proportion was still more obvious than other bacteria.While,in the upper respiratory,prevotella increase obviously,besides streptococcus,neisseria,staphylococcus epidermidis,Corynebacterium,streptococcus digestive,veillonella and actinomycetes.Furthermore,in the samples of tuberculosis patients,the abundance of prevotella is significantly different from sample to sample,though prevotella is the dominant bacterium.Conclusion: compared the respiratory tract flora of heathy people and pulmonary tuberculosis patients,I find that the respiratory microorganism of pulmonary tuberculosis patients is significantly different from that of healthy people.Besides the increase and abundance of bacterial species,pulmonary tuberculosis respiratory tract has its own unique bacterial species,which suggests that this unique bacterium is probably associated with the occurrence and development of pulmonary tuberculosis.In addition,the abundance of bacteria is possibly related to the use of antibiotics.