RecruitingDiagnostic testPatienthèque of Finisterian (South of Brittany) Children With Cystic Fibrosis in the Time of Precision MedicineThe objective of this study is to evaluate the relevance of Porphyromonas as a biomarker predicting the risk of P. aeruginosa primocolonization in children form 0 to 18 years old with cystic fibrosis.