Sebastian Fischer1, Leonie Greipel1, Jens Klockgether1, Marie Dorda1, Lutz Wiehlmann1, Nina Cramer1, Burkhard Tümmler2. 1. Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Clinic for Paediatric Pneumology, Allergology and Neonatology, OE 6710, Hannover Medical School, Hannover, Germany. 2. Clinical Research Group 'Molecular Pathology of Cystic Fibrosis', Clinic for Paediatric Pneumology, Allergology and Neonatology, OE 6710, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany. Electronic address: tuemmler.burkhard@mh-hannover.de.
Abstract
BACKGROUND: Early antimicrobial chemotherapy can prevent or at least delay chronic cystic fibrosis (CF) airways infections with Pseudomonas aeruginosa. METHODS: During a 10-year study period P. aeruginosa was detected for the first time in 54 CF patients regularly seen at the CF centre Hannover. Amplicon sequencing of 34 loci of the P. aeruginosa core genome was performed in baseline and post-treatment isolates of the 15 CF patients who had remained P. aeruginosa - positive after the first round of antipseudomonal chemotherapy. RESULTS: Deep sequencing uncovered coexisting alternative nucleotides at in total 33 of 55,284 examined genome positions including six non-synonymous polymorphisms in the lasR gene, a key regulator of quorum sensing. After early treatment 42 of 50 novel nucleotide substitutions had emerged in exopolysaccharide biosynthesis, efflux pump and porin genes. CONCLUSIONS: Early treatment selects pathoadaptive mutations in P. aeruginosa that are typical for chronic infections of CF lungs.
BACKGROUND: Early antimicrobial chemotherapy can prevent or at least delay chronic cystic fibrosis (CF) airways infections with Pseudomonas aeruginosa. METHODS: During a 10-year study period P. aeruginosa was detected for the first time in 54 CFpatients regularly seen at the CF centre Hannover. Amplicon sequencing of 34 loci of the P. aeruginosa core genome was performed in baseline and post-treatment isolates of the 15 CFpatients who had remained P. aeruginosa - positive after the first round of antipseudomonal chemotherapy. RESULTS: Deep sequencing uncovered coexisting alternative nucleotides at in total 33 of 55,284 examined genome positions including six non-synonymous polymorphisms in the lasR gene, a key regulator of quorum sensing. After early treatment 42 of 50 novel nucleotide substitutions had emerged in exopolysaccharide biosynthesis, efflux pump and porin genes. CONCLUSIONS: Early treatment selects pathoadaptive mutations in P. aeruginosa that are typical for chronic infections of CF lungs.