Differences Analysis Of Oropharyngeal Microbiota Between Children With Respiratory Tract Infection And Healthy Children

Objective: 16S rRNA gene sequencing was used to identify the difference of oropharyngeal microbiota between children with community-acquired pneumonia(CAP),acute suppurative tonsillitis(AST)and health children.Methods: The three groups of throat swab samples were collected from the first patients in our hospital from December 2019 to July2020,including 31 cases of communit-acquired pneumonia,9 cases of acute suppurative tonsillitis,10 cases of healthy children without infection evidence in orthopedic pediatrics as control group(CG).Based on Illumina Miseq sequencing platform,the V3-V4 region of 16 S rRNA gene was amplified and sequenced,and the characteristics of oropharyngeal microbiota were analyzed.No antibiotics or microecological agents were used in all children within 3days before sampling.Results:(1)Compared with CG group,Shannon index,Obeserved＿OTUs number and faith＿PD of CAP group were all P < 0.05,with statistically significan;but there was no significant difference between AST group and CG group(P > 0.05);There was no significant difference in Evenness index between CG group and CAP group,CG group and AST group.(2)At the phylum level,the dominant phylum of the three groups were Firmicutes,Bacteroides,Proteus and Fusobacteria,and the oropharyngeal microbiota in CAP,AST and CG groups had no significant difference;(3)At the genus level,the dominant genera in CAP group were Streptococcus,Prevotella7,Veillonella,Neisseria,Haemophilus,Leptotrichia and Porphyromonas;the dominant genera in AST group were Streptococcus,Prevotella7,veronilla,Neisseria,Porphyromonas,Fusobacterium and Twincoccus;and in CG group were Streptococcus,Prevotella7,veroniella,Leptotrichia,Neisseria,Alloprevotella and Porphyromonas;(4)Compared with CG group,the relative abundance of Gemella was higher in CAP group(P= 0.022<0.05),other TM7 phylum sp.oral clone DR034、Megas Phaera and Campylobacter relative abundance decreased(P = 0.049<0.05,P =0.013<0.05,P = 0.005<0.01),the difference was statistically significant;AST group compared with CG group,Leptotrichia relative abundance decreased(P= 0.035<0.05),the difference was statistically significant.Conclusions:(1)Compared with healthy children,the structure of some dominant bacteria of oropharyngeal mirobiota in children with respiratory tract infection changed,the relative abundance of Gemella in ropharyngeal of CAP children increased,and relative abundance of TM7 phylum sp.oral clone DR034、Megas Phaera and Campylobacter decreased;the relative abundance of Leptotrichia in ropharyngeal of AST children decreased.(2)Compared with healthy children,the richness of oropharyngeal mirobiota in children with CAP decreased significantly,but there was no significant change in the structure of oropharyngeal mirobiota in children with AST,indicating that lower respiratory tract infection may have a greater impact on oropharyngeal mirobiota balance than upper respiratory tract infection.