Study On Sputum Microbiome Of Different Clinical Types Of AECOPD

Objective: Chronic obstructive pulmonary disease(COPD)has a high incidence in the world.And acute exacerbation of COPD leads to increased economic burden of patients with hospitalization,and affects the quality of life of patients.Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is often accompanied by other pulmonary diseases,which aggravates the condition and affects the prognosis.In this study,high-throughput sequencing was used to analyze the composition and diversity of sputum bacteria and fungi in AECOPD,AECOPD with asthma,and AECOPD with bronchiectasis.Meanwhile,the characteristics of sputum microbiome with different NLR(neutrophil lymphocyte ratio,NLR)were explored.The characteristics and changes of microbial composition under different conditions of AECOPD are deeply understood,which provide microbial direction for clinical diagnosis and treatment.Method: Sputum samples were collected from patients with AECOPD,AECOPD with asthma,and AECOPD with bronchiectasis within 24 hours after admission.And clinical characteristics of these patients were also collected in the Department of Respiratory and Critical Care Medicine,Affiliated Hospital of Southwest Medical University.The sputum samples were screened according to the inclusion and exclusion criteria and divided into AECOPD group(n=14),AECOPD with asthma group(n=7),and AECOPD with bronchiectasis group(n=8).AECOPD group was divided into high NLR group(HNLR,n=7)and low NLR group(LNLR,n=7)according to the median NLR value.Subsequently,genomic DNA was extracted from sputum samples.V3-V4 hypervariable region for 16 S rDNA(16S ribosomal deoxyribonucleic acid)high-throughput sequencing was selected in bacteria.ITS1(internal transcribed spacer 1,ITS1)hypervariable region for high-throughput sequencing was selected in fungi.Bioinformatics analysis technology was used to analyze the composition of bacterial and fungal among the sequencing results.And α and βdiversity analysis was conducted to find the differences between the groups.Result: 1.The dominant flora at the phylum level of AECOPD,AECOPD with asthma,and AECOPD with bronchiectasis were Proteobacteria,Firmicutes,and Bacteroidetes.While at the genus level,the dominant bacteria were Streptococcus,Haemophilus and Neisseria.In terms of fungi,the dominant fungi at the phylum level were Ascomycetes and Basidiomycetes,while the dominant fungi at the genus level were Candida.And the abundance of bacteria was different among different groups.2.The abundances of Verrucomicrobia,Spirochaeates and Synergistetes were different between AECOPD and AECOPD with bronchiectasis(P < 0.05),and the abundances of Purmonaceae and Moraxella were different between AECOPD and AECOPD with asthma(P< 0.05).But there was no significant difference in the abundance of Ascomycetes,Basidiomycetes between AECOPD group and AECOPD with asthma group and AECOPD with bronchiectasis group(P > 0.05).And there was no significant difference in the abundance of Candida at the genus level(P >0.05).3.The bacterial β diversity of AECOPD patients with asthma and AECOPD patients with bronchiectasis was higher than that of AECOPD patients;however,there was no significant difference in fungal diversity.4.The phylum level of the HNLR group was mainly composed of Firmicutes,while that of the LNLR group was mainly composed of Proteobacteria.At genus level,the dominant bacteria in HNLR group were Streptococcus,and the dominant bacteria in LNLR group were Haemophilus.The abundance of Proteobacteria,Haemophilus and Streptococcus were significantly different between the two groups(P < 0.05).5.The diversity analysis of HNLR and LNLR bacteria showed that the Chao1 and ACE indexes of HNLR group were higher than those of LNLR group.And the β diversity of LNLR group was higher.Fungal analysis showed that there was no significant difference in αdiversity between HNLR and LNLR groups.However,β diversity increased in LNLR group.Conclusion: High-throughput sequencing analysis can improve the detection of microflora,which is beneficial to the analysis of microflora characteristics among different groups.The composition and diversity of sputum bacteria were different between AECOPD and AECOPD with asthma,and between AECOPD with bronchiectasis.The abundance of fungi was different among the three groups.However,there was no significant difference in the abundance and diversity of fungi among the three groups.The abundance of Proteobacteria,Haemophilus and Streptococcus were correlated with the NLR value of AECOPD patients.