A new study published in NPJ Biofilms and Microbiomes investigated metagenome development of the human respiratory tract by shotgun metagenome metagenomic sequencing of cough swabs from healthy children and children with cystic fibrosis (CF) – between three weeks and six years of age.

The results revealed that a healthy microbial community signature was associated with increased absolute abundances in terms of bacterial-human cell ratios of core and rare species across all age groups, with a higher diversity of rare species and a tightly interconnected species co-occurrence network—in which individual members were found in close proximity to each other—while negative correlations were absent. Additionally, even without typical CF pathogens, the CF infant co-occurrence network was found to be less stable and prone to fragmentation due to fewer connections between species, a higher number of bridging species and the presence of negative species correlations. Detection of low-abundant DNA of the CF hallmark pathogen – Pseudomonas aeruginosa, was neither disease- nor age-associated in this cohort. 

From the findings, it was concluded that healthy and CF children come into contact with P. aeruginosa on a regular basis, and from an early age.

Source: NPJ Biofilms and Microbiomes. 2020 Dec 15;6(1):61. doi: 10.1038/s41522-020-00171-7.