Trikafta/Kaftrio and Pseudomonas Aeruginosa

The goal of this observational study o is to define whether, how and to what extent treatment with Trikafta/Kaftrio directly affects Pseudomonas aeruginosa in individuals with cystic fibrosis. The main questions it aims to answer are:whether Trikafta/Kaftrio affects the bacterial phenotypes and susceptibility to antibiotics;whether Trikafta/Kaftrio impacts the bacterial virulence. Participants will be asked the permission to store and analyze P. aeruginosa isolates collected from respiratory samples for usual care plans before the initiation of treatment with Trikafta/Kaftrio and after 12 and 18 months of treatment. The results of bacterial analysis will be matched with clinical data at the specific time-points.We expect to define effects of Trikafta/Kaftrio on P. aeruginosa and identify bacterial phenotypes as possible risk factors for its efficacy.

Inclusion Criteria:Definite diagnosis of CF and regular follow up, in accordance with the standard operating procedures in force at the CentresHomozygous for the F508del mutation (F508del/F508del) in the CFTR gene or heterozygous for the F508del mutation and with a minimal function mutation in the other allele (F508del/minimum function mutation)Chronically infected with P. aeruginosa (defined as having at least 50% or more sputum cultures positive for P. aeruginosa in the previous year)Candidates starting treatment with Kaftrio or being treated with Kaftrio (retrospective phase)Both sexes aged >12 yearsObtaining informed consent from patients and/or from patients' parents (according to the modalities foreseen by the protocol)Exclusion Criteria:Patients unable to understand the instructions and information provided and to be able to adequately accept the modalities of the study.Patients unable to expectorate.Patients with negative sputum for P. aeruginosa at T0, which in the case of prospective patients corresponds to the time of enrollment.