Cystic fibrosis is the most common hereditary autosomal recessive disease in the Caucasian population. The diseases is caused by a mutation of the gene coding for the CFTR protein (Cystic fibrosis transmembrane conductance regulator), an ion channel present at the apical pole of the epithelial cells. The channel dysfunction induces a deficit in hydration and a hyperviscosity of different exocrine secretions.

Clinically, Cystic fibrosis is a multi-systemic disease. Pulmonary and pancreatic involvement are classically in the foreground. Degradation of respiratory function, associated with acute and chronic infections, represents the major cause of morbidity and mortality.

Pseudomonas aeruginosa is a ubiquitous gram-negative bacillus found primarily in stagnant water. Pseudomonas aeruginosa is capable of colonizing the digestive, pulmonary and urinary mucosa and the skin. This bacterium is incriminated in many opportunistic infections including respiratory infections in patients with cystic fibrosis. Pseudomonas aeruginosa infection is the most common parenchymal lung infection in the Cystic fibrosis community.

Pseudomonas aeruginosa chronic carriage represents a factor of poor prognosis associated with an increase in morbidity and mortality. Complications related to chronic carriage of Pseudomonas aeruginosa justify the implementation of strategies of eviction, screening and eradication of acute Pseudomonas aeruginosa infection.

In addition to Pseudomonas aeruginosa contamination of patients via the environment, hand and airborne infections between patients with Cystic fibrosis have been reported. Measures to eliminate cross-transmissions have therefore been implemented in a majority of hospitals.

The aim of the study is firstly to identify the number of Pseudomonas aeruginosa cross-transmissions between patients with Cystic fibrosis followed-up in Cystic fibrosis center of HUDERF. Investigator will use the Pulsed-Field Gel Electrophoresis to assess the possibility of cross-infection.

Depending on the results, Investigator will implement new strategies to avoid future cross-contamination in our different places of care (consultation, hospitalization, physiotherapy…).

Inclusion Criteria:

• Cystic fibrosis patients aged 0-20y followed in Cystic fibrosis at HUDERF
• For each participant, both parents or legally acceptable representative(s) must sign an informed consent form (ICF) indicating that they understand the purpose of, and procedures required for, the study and is willing to allow the child to participate in the study.
• Assent is also required of children capable of understanding the study (typically participants 7 years of age and older).

Exclusion Criteria:

• None

Cystic fibrosis patients followed-up in cystic fibrosis center in Brussels.