Background: Cystic Fibrosis (CF) is a multi-organ genetic disorder characterized by chronic airway infections. While Pseudomonas aeruginosa typically becomes the dominant pathogen as the disease progresses, some pediatric cases exhibit unusual colonization patterns. Case Presentation: We report the case of a 5-year-old male patient (M.R.) presenting with recurrent respiratory distress and growth failure. Diagnosis was confirmed by a positive sweat chloride test (>60 mmol/L). Microbiological Findings: Contrary to the expected transition towards Pseudomonas-dominant lungs, repeated cultures and antibiograms consistently showed a heavy and exclusive colonization of Staphylococcus aureus. This persistent "Staph-dominant" profile, despite clinical exacerbations, is an atypical finding in symptomatic pediatric patients. Conclusion: This case highlights the necessity of personalized, culture-guided antibiotic therapy and challenges the systematic assumption of Pseudomonas emergence in early childhood CF management.
Zarhloul Sami*, Bougoun Hamza, Dadi Chaymae, Benaouda Amina (2026) studied this question.