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Impact of the CFTR-potentiator ivacaftor on airway microbiota in cystic fibrosis patients carrying a G551D mutation.

Bernarde C, Keravec M, Mounier J, Gouriou S, Rault G, Férec C, Barbier G, Héry-Arnaud G - PLoS ONE (2015)

Bottom Line: There was no significant difference in total bacterial load before and after treatment.Comparison of global community composition found no significant changes in microbiota.Two OTUs, however, showed contrasting dynamics: after initiation of ivacaftor, the relative abundance of the anaerobe Porphyromonas 1 increased (p<0.01) and that of Streptococcus 1 (S. mitis group) decreased (p<0.05), possibly in relation to the anti-Gram-positive properties of ivacaftor.

View Article: PubMed Central - PubMed

Affiliation: EA 3882-Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Université de Brest, Brest, France.

ABSTRACT

Background: Airway microbiota composition has been clearly correlated with many pulmonary diseases, and notably with cystic fibrosis (CF), an autosomal genetic disorder caused by mutation in the CF transmembrane conductance regulator (CFTR). Recently, a new molecule, ivacaftor, has been shown to re-establish the functionality of the G551D-mutated CFTR, allowing significant improvement in lung function.

Objective and methods: The purpose of this study was to follow the evolution of the airway microbiota in CF patients treated with ivacaftor, using quantitative PCR and pyrosequencing of 16S rRNA amplicons, in order to identify quantitative and qualitative changes in bacterial communities. Three G551D children were followed up longitudinally over a mean period of more than one year covering several months before and after initiation of ivacaftor treatment.

Results: 129 operational taxonomy units (OTUs), representing 64 genera, were identified. There was no significant difference in total bacterial load before and after treatment. Comparison of global community composition found no significant changes in microbiota. Two OTUs, however, showed contrasting dynamics: after initiation of ivacaftor, the relative abundance of the anaerobe Porphyromonas 1 increased (p<0.01) and that of Streptococcus 1 (S. mitis group) decreased (p<0.05), possibly in relation to the anti-Gram-positive properties of ivacaftor. The anaerobe Prevotella 2 correlated positively with the pulmonary function test FEV-1 (r=0.73, p<0.05). The study confirmed the presumed positive role of anaerobes in lung function.

Conclusion: Several airway microbiota components, notably anaerobes (obligate or facultative anaerobes), could be valuable biomarkers of lung function improvement under ivacaftor, and could shed light on the pathophysiology of lung disease in CF patients.

No MeSH data available.


Related in: MedlinePlus

Dynamics and interrelations of 7 key-role OTUs throughout ivacaftor treatment, and their correlations with lung function.Streptococcus 1 (S. mitis group) and Porphyromonas 1 were the two OTUs for which a significant association with ivacaftor treatment period emerged (Colin-White test; See S2 Table): Streptococcus 1 (S. mitis group) was associated with sputum samples collected before (p<0.05) and Porphyromonas 1 with samples collected after initiation of treatment (p<0.01). The depicted correlations between OTUs were all statistically significant with the adjusted p-values (Spearman correlation test; see Table 3). Significant correlations between OTUs and lung function (on FEV-1 test) are shown by red arrow when negative (p<0.05) and green arrow (light green if p<0.1; dark green if p<0.05) when positive (adjusted p-values; see Table 2).
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pone.0124124.g005: Dynamics and interrelations of 7 key-role OTUs throughout ivacaftor treatment, and their correlations with lung function.Streptococcus 1 (S. mitis group) and Porphyromonas 1 were the two OTUs for which a significant association with ivacaftor treatment period emerged (Colin-White test; See S2 Table): Streptococcus 1 (S. mitis group) was associated with sputum samples collected before (p<0.05) and Porphyromonas 1 with samples collected after initiation of treatment (p<0.01). The depicted correlations between OTUs were all statistically significant with the adjusted p-values (Spearman correlation test; see Table 3). Significant correlations between OTUs and lung function (on FEV-1 test) are shown by red arrow when negative (p<0.05) and green arrow (light green if p<0.1; dark green if p<0.05) when positive (adjusted p-values; see Table 2).

Mentions: Ge: Gemella, Str2: Streptococcus 2 (S. salivarius group), Neis2: Neisseria, Ha1: Haemophilus 1, Neis1: Neisseria 1, Pre2: Prevotella 2, Sta: Staphylococcus aureus, Fus1: Fusobacterium 1, Rot2: Rothia 2, Pre1: Prevotella 1, Rot1: Rothia 1, Str3: Streptococcus 3 (S. anginosus group), Str1: Streptococcus 1 (S. mitis group), Vei1: Veillonella 1, Other: OTUs out of the major core microbiota, Pept: Peptostreptococcus, Por1: Pophyromonas 1.


Impact of the CFTR-potentiator ivacaftor on airway microbiota in cystic fibrosis patients carrying a G551D mutation.

Bernarde C, Keravec M, Mounier J, Gouriou S, Rault G, Férec C, Barbier G, Héry-Arnaud G - PLoS ONE (2015)

Dynamics and interrelations of 7 key-role OTUs throughout ivacaftor treatment, and their correlations with lung function.Streptococcus 1 (S. mitis group) and Porphyromonas 1 were the two OTUs for which a significant association with ivacaftor treatment period emerged (Colin-White test; See S2 Table): Streptococcus 1 (S. mitis group) was associated with sputum samples collected before (p<0.05) and Porphyromonas 1 with samples collected after initiation of treatment (p<0.01). The depicted correlations between OTUs were all statistically significant with the adjusted p-values (Spearman correlation test; see Table 3). Significant correlations between OTUs and lung function (on FEV-1 test) are shown by red arrow when negative (p<0.05) and green arrow (light green if p<0.1; dark green if p<0.05) when positive (adjusted p-values; see Table 2).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390299&req=5

pone.0124124.g005: Dynamics and interrelations of 7 key-role OTUs throughout ivacaftor treatment, and their correlations with lung function.Streptococcus 1 (S. mitis group) and Porphyromonas 1 were the two OTUs for which a significant association with ivacaftor treatment period emerged (Colin-White test; See S2 Table): Streptococcus 1 (S. mitis group) was associated with sputum samples collected before (p<0.05) and Porphyromonas 1 with samples collected after initiation of treatment (p<0.01). The depicted correlations between OTUs were all statistically significant with the adjusted p-values (Spearman correlation test; see Table 3). Significant correlations between OTUs and lung function (on FEV-1 test) are shown by red arrow when negative (p<0.05) and green arrow (light green if p<0.1; dark green if p<0.05) when positive (adjusted p-values; see Table 2).
Mentions: Ge: Gemella, Str2: Streptococcus 2 (S. salivarius group), Neis2: Neisseria, Ha1: Haemophilus 1, Neis1: Neisseria 1, Pre2: Prevotella 2, Sta: Staphylococcus aureus, Fus1: Fusobacterium 1, Rot2: Rothia 2, Pre1: Prevotella 1, Rot1: Rothia 1, Str3: Streptococcus 3 (S. anginosus group), Str1: Streptococcus 1 (S. mitis group), Vei1: Veillonella 1, Other: OTUs out of the major core microbiota, Pept: Peptostreptococcus, Por1: Pophyromonas 1.

Bottom Line: There was no significant difference in total bacterial load before and after treatment.Comparison of global community composition found no significant changes in microbiota.Two OTUs, however, showed contrasting dynamics: after initiation of ivacaftor, the relative abundance of the anaerobe Porphyromonas 1 increased (p<0.01) and that of Streptococcus 1 (S. mitis group) decreased (p<0.05), possibly in relation to the anti-Gram-positive properties of ivacaftor.

View Article: PubMed Central - PubMed

Affiliation: EA 3882-Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Université de Brest, Brest, France.

ABSTRACT

Background: Airway microbiota composition has been clearly correlated with many pulmonary diseases, and notably with cystic fibrosis (CF), an autosomal genetic disorder caused by mutation in the CF transmembrane conductance regulator (CFTR). Recently, a new molecule, ivacaftor, has been shown to re-establish the functionality of the G551D-mutated CFTR, allowing significant improvement in lung function.

Objective and methods: The purpose of this study was to follow the evolution of the airway microbiota in CF patients treated with ivacaftor, using quantitative PCR and pyrosequencing of 16S rRNA amplicons, in order to identify quantitative and qualitative changes in bacterial communities. Three G551D children were followed up longitudinally over a mean period of more than one year covering several months before and after initiation of ivacaftor treatment.

Results: 129 operational taxonomy units (OTUs), representing 64 genera, were identified. There was no significant difference in total bacterial load before and after treatment. Comparison of global community composition found no significant changes in microbiota. Two OTUs, however, showed contrasting dynamics: after initiation of ivacaftor, the relative abundance of the anaerobe Porphyromonas 1 increased (p<0.01) and that of Streptococcus 1 (S. mitis group) decreased (p<0.05), possibly in relation to the anti-Gram-positive properties of ivacaftor. The anaerobe Prevotella 2 correlated positively with the pulmonary function test FEV-1 (r=0.73, p<0.05). The study confirmed the presumed positive role of anaerobes in lung function.

Conclusion: Several airway microbiota components, notably anaerobes (obligate or facultative anaerobes), could be valuable biomarkers of lung function improvement under ivacaftor, and could shed light on the pathophysiology of lung disease in CF patients.

No MeSH data available.


Related in: MedlinePlus