Analysis of airway microbiota in adults from a Brazilian cystic fibrosis center

Abstract

The application of next-generation sequencing tools revealed that the cystic fibrosis respiratory tract is a polymicrobial environment. We have characterized the airway bacterial microbiota of five adult patients with cystic fibrosis during a 14-month period by 16S rRNA tag sequencing using the Illumina technology. Microbial diversity, estimated by the Shannon index, varied among patient samples collected throughout the follow-up period. The beta diversity analysis revealed that the composition of the airway microbiota was highly specific for each patient, showing little variation among the samples of each patient analyzed over time. The composition of the bacterial microbiota did not reveal any emerging pathogen predictor of pulmonary disease in cystic fibrosis or of its unfavorable clinical progress, except for unveiling the presence of anaerobic microorganisms, even without any established clinical association. Our results could potentialy help us to translate and develop strategies in response to the pathobiology of this disease, particularly because it represents an innovative approach for CF centers in Brazil.

Keywords: Airway microbiota; Cystic fibrosis; Next-generation sequencing.

Fig. 1

Relative abundance of bacterial phyla detected in sputum samples collected from five different patients assessed by 16S rRNA V4 tag sequencing using Illumina technology. The colored segments of each bar represent the proportion of OTUs assigned to different bacterial phyla

Fig. 2

Relative abundance of bacterial genera detected in sputum samples collected from five different patients assessed by 16S rRNA V4 tag sequencing using Illumina technology. The colored segments of each bar represent the proportion of OTUs assigned to different 20 most abundant bacterial genera present in the samples in a higher than 1% occurrence

Fig. 3

Shannon index showing diversity, driven by community richness (number of OTUs detected) and community evenness (relative abundance of OTUs). Each bar representes a patient sample collected over the sudy period (patients A, B, C, D, and E)

Fig. 4

PcoA plot of Bray-Curtis dissimilarity for bacterial communities from samples from the five patients collected at different time-points. Red circles = patient A; brown circles = patient B; orange circles = patient C; green circles = patient D; blue circles = patient E