Mycoplasma pneumoniae and Streptococcus pneumoniae caused different microbial structure and correlation network in lung microbiota

Abstract

Pneumonia is one of the most serious diseases for children, with which lung microbiota are proved to be associated. We performed 16S rDNA analysis on broncho-alveolar lavage fluid (BALF) for 32 children with tracheomalacia (C group), pneumonia infected with Streptococcus pneumoniae (S. pneumoniae) (D1 group) or Mycoplasma pneumoniae (M. pneumoniae) (D2 group). Children with tracheomalacia held lower microbial diversity and accumulated Lactococcus (mean ± SD, 45.21%±5.07%, P value <0.05), Porphyromonas (0.12%±0.31%, P value <0.05). D1 and D2 group were enriched by Streptococcus (7.57%±11.61%, P value <0.01 when compared with D2 group) and Mycoplasma (0.67%±1.25%, P value <0.01) respectively. Bacterial correlation in C group was mainly intermediated by Pseudomonas and Arthrobacter. Whilst, D1 group harbored simplest microbial correlation in three groups, and D2 group held the most complicated network, involving enriched Staphylococcus (0.26%±0.71%), Massilia (0.81%±2.42%). This will be of significance for understanding pneumonia incidence and progression more comprehensively, and discerning between bacterial infection and carriage.

Keywords: Mycoplasma pneumoniae (M. pneumoniae); Pneumonia; Streptococcus pneumoniae (S. pneumoniae); microbiota.

Conflict of interest statement

Conflicts of Interest: The authors have no conflicts of interest to declare.

Figures

Figure 1

Bacterial structure in C, D1 and D2 group, at genus level. SVG (version 1.1) was used to produce the paragraph, based on relative abundance of each genus. The circle square of each genus represents total relative abundance in three groups, and the line linking C, D1 and D2 group means relative abundance for each group (proportional to line thickness). SVG, Scalable Vector Graphics.

Figure 2

Alpha-diversity for microbial in C, D1 and D2 group. Shannon’s diversity is proportional to microbial diversity, and Simpson’s diversity is negatively correlated with diversity. Based on the two indexes, C group hold lower microbial diversity.

Figure 3

Bacterial correlation in C, D1 and D2 group. Microbial species with >0.1% relative abundance were selected to analyze correlation network, with Pearson index >0.9. The correlation network was mainly mediated by Pseudomonas and Arthrobacter, involving most of normal colonizers. When children got pneumonia, interaction network in C group were broken up: simpler in D1 group and more complicated in D2 group with another tight correlation circle constituted by enriched Staphylococcus, Massilia and Propionibacterium. The circle square is proportional to relative abundance, red line means positive correlation.