Inhaled Levofloxacin in a Combination Regimen for Stenotrophomonas maltophilia Chronic Bronchial Infection in Non-Cystic Fibrosis Bronchiectasis: A Case Report.

Chronic bronchial infection by Stenotrophomonas maltophilia in non-cystic fibrosis (non-CF) bronchiectasis poses a major therapeutic challenge due to multidrug resistance and biofilm-forming capacity. We report a 19-year-old athlete with a one-year history of productive cough, dyspnea, and hemoptysis, whose CT scan revealed bibasilar cylindrical bronchiectasis. Following the failure of oral levofloxacin monotherapy and a subsequent sputum culture showing intermediate susceptibility to cotrimoxazole, a combination regimen was initiated. The patient received systemic trimethoprim-sulfamethoxazole combined with intermittent 28-day cycles of inhaled levofloxacin to leverage drug synergy and achieve high local concentrations capable of penetrating the bacterial biofilm. This dual approach achieved complete symptomatic remission, stable lung function, and microbiological clearance. To our knowledge, this is the first report documenting successful S. maltophilia eradication using inhaled levofloxacin in non-CF bronchiectasis, suggesting that this combination may be an alternative therapeutic strategy deserving further evaluation in future studies.