The characteristic of upper and lower airway microbiota of children with lobar pneumonia

Lobar pneumonia is a serious pediatric health issue. The pathogen spectrum has changed in recent years, with Mycoplasma pneumoniae (MP) becoming the most common pathogen, followed by Streptococcus pneumoniae. Therefore, exploring the characteristics of upper and lower respiratory tract microbiota of lobar pneumonia has important clinical significance. Nasopharyngeal swab (NPS) and bronchoalveolar lavage fluid (BALF) samples collected from lobar pneumonia children(n=40) were analyzed by 16 S ribosomal RNA (rRNA) sequencing. The children with lobar pneumonia were divided into two groups based on pathogens: MP infection (A group, n=28) and non-MP infection (B group, n=12). Distinct microbiota profiles at both the phylum and genus levels were observed in the MP and non-MP infection children. A clear difference in alpha diversity between BALF of MP and non-MP infection groups was uncovered. Principal coordinate analysis (PCoA) revealed distinct distribution of upper and lower airway microbial communities among MP infection children, while upper and lower airway bacterial communities were largely overlapping among non-MP infection children. Correlation analyses indicated associations between the lower airway microbiota and clinical parameters such as procalcitonin (PCT) levels and white blood cell (WBC) counts. There are differences between the upper and lower airway microbiota of children with lobar pneumonia of MP and non-MP infection. The lower airway microbiota had correlations with clinical parameters, deserving further investigations.