@article{mbs:/content/journal/jmm/10.1099/jmm.0.015875-0, author = "Fothergill, Joanne L. and Mowat, Eilidh and Ledson, Martin J. and Walshaw, Martin J. and Winstanley, Craig", title = "Fluctuations in phenotypes and genotypes within populations of Pseudomonasaeruginosa in the cystic fibrosis lung during pulmonary exacerbations", journal= "Journal of Medical Microbiology", year = "2010", volume = "59", number = "4", pages = "472-481", doi = "https://doi.org/10.1099/jmm.0.015875-0", url = "https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.015875-0", publisher = "Microbiology Society", issn = "1473-5644", type = "Journal Article", keywords = "CF, cystic fibrosis", keywords = "LES, Liverpool epidemic strain", keywords = "BSAC, British Society for Antimicrobial Chemotherapy", abstract = "Chronic respiratory infection by Pseudomonas aeruginosa contributessignificantly to the morbidity and mortality associated with cystic fibrosis (CF).Using a series of phenotypic and genotypic tests on collections of 40 isolatesper sputum sample, we analysed fluctuations within sputum populations of the P. aeruginosa Liverpool epidemic strain (LES) during pulmonaryexacerbations. For each of three patients, three sequential sputum sampleswere analysed: (1) on presentation with exacerbation at the RegionalAdult Cystic Fibrosis Unit, Liverpool; (2) a few days into intravenousantibiotic treatment; (3) when the patient had recovered. Fluctuationswere observed in morphotype distribution, the production of virulence-associatedquorum-sensing-dependent exoproducts (the phenazine compound pyocyaninand the elastase LasA), antibiotic susceptibility profiles and levelsof auxotrophy. PCR assays were used to screen isolates for the presence ofnovel regions of the LES genome (islands and prophages) and to detectfree phages. In one patient there was an increase in the prevalence of theLESGI-5 genomic island during the sampling period from 10 to 97.5 %carriage. LES phages 2–4 were detected in either the majority or allsputum samples tested, indicating widespread phage activity during the samplingperiod. The results of this study are indicative that significant fluctuationsoccur within P. aeruginosa populations during short periods of pulmonaryexacerbation and intravenous antibiotic therapy.", }