Preliminary Observation On The Effect Of Antibacterials On Microbiota In Infancy

Objective: Preliminary observation on the impact of antibacterials administration on the diversity and structure of microbiota in infants with pneumonia.Methods: Stool specimens of 6 infants with mild community acquired pneumonia before and five to seven days,a month and three months after antimicrobial treatment were collected.The sequences of Regions V3-V4 of bacterial 16 S rRNA gene were generated with high-throughput sequencing on Illumina Mi Seq sequencing platform.Results: The diversity of oropharyngeal and gut microbiota was significantly decreased,but incresaed in nasopharyngeal flora after five to seven days treatment with antibacterials.The average relative abundance of Proteobacteria and Fusobacteria decreased,but that of Firmicutes incresaed after 5-7 days treatment with antibacterials.The average relative abundance of Streptococcus,Rothia in oral cavity,Streptococcus,Veillonella,Rothia,Actinomyces,Bifidobacterium,Bacillus,Clostridium,Dysgonomonas,Acidaminococcus and Megasphaera in nasopharynx,and Enterococcus,Escherichia,Rothia,Moraxella and Granulicatella in the gut were increased,but the level of Veillonella,Prevotella,Haemophilus,Moraxella,Actinomyces,Gemella,Leptotrichia,Atopobium,Neisseria and Fusobacterium in oral cavity,Haemophilus,Moraxella,Neisseria and Staphylococcus in nasal cavity,Haemophilus,Clostridium,Prevotella,Bifidobacterium,Blautia,Megasphaera,Hungatella and Erysipelatoclostridium in the gut were decreased.The structure ofmicrobiota and the relative abundance of microbial diversity in some children can't return to normal in three months.Conclusion:Antibacterials exposure in infants with pneumonia after 5-7days lead to significantly decreased in oropharyngeal and gut microbial diversity,but incresae in nasopharyngeal flora;dysbiosis of microbiota,the structure of microbiota and the relative abundance of microbial diversity in some children can't return to normal inthree months.