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ABSTRACT: Background
Pulmonary exacerbations in cystic fibrosis (CF) remain poorly understood and treatment is usually targeted at Pseudomonas aeruginosa. Within Australia a predominant shared P. aeruginosa strain (AUST-02) is associated with greater treatment needs. This single centre study assessed temporal shared strain population dynamics during and after antibiotic treatment of exacerbations.Methods
Sputum was collected from 12 adult patients with a history of chronic AUST-02 infection at four time-points during and after treatment of an exacerbation. Forty-eight P. aeruginosa isolates within each sample underwent AUST-02 allele-specific PCR and SNP-based strain genotyping.Results
Various commonly shared Australian strains (AUST-01, 0.1%; AUST-02, 54.3%; AUST-06, 36.6%; AUST-07, 4.6%; AUST-11, 4.3%) and two unique strains (0.1%) were identified from 45 sputum samples (2160 isolates). Based on within-patient relative abundance of strains, a "single-strain infection" (n = 7) or "mixed-strain infection" (n = 5) was assigned to each patient. A significant temporal variation in the P. aeruginosa population composition was found for those with mixed-strain infection (P < 0.001). Patients with mixed-strain infections had more long-term treatment requirements than those with single-strain infection. Moreover, despite both groups having similar lung function at study entry, patients with single-strain infection had greater improvement in FEV1% predicted following their exacerbation treatment (P = 0.02).Conclusion
Pulmonary exacerbations may reveal multiple, unrelated P. aeruginosa strains whose relative abundance with one another may change rapidly, in a sustained and unpredictable manner.
SUBMITTER: Tai AS
PROVIDER: S-EPMC5667482 | biostudies-literature | 2017 Nov
REPOSITORIES: biostudies-literature
Tai Anna S AS Sherrard Laura J LJ Kidd Timothy J TJ Ramsay Kay A KA Buckley Cameron C Syrmis Melanie M Grimwood Keith K Bell Scott C SC Whiley David M DM
BMC pulmonary medicine 20171102 1
<h4>Background</h4>Pulmonary exacerbations in cystic fibrosis (CF) remain poorly understood and treatment is usually targeted at Pseudomonas aeruginosa. Within Australia a predominant shared P. aeruginosa strain (AUST-02) is associated with greater treatment needs. This single centre study assessed temporal shared strain population dynamics during and after antibiotic treatment of exacerbations.<h4>Methods</h4>Sputum was collected from 12 adult patients with a history of chronic AUST-02 infectio ...[more]