Case Report: Bacteriophage-antibiotic therapy for extensively drug-resistant Acinetobacter baumannii in critically ill patient with respiratory infection.

Extensively drug-resistant Acinetobacter baumannii (XDR A. baumannii) poses a crucial challenge due to high mortality and limited therapies. Here, we report the successful application of phage-antibiotic synergy in a critically ill patient with two months of ineffective antibiotic treatment. The patient was diagnosed with severe pneumonia due to recurrent infection of XDR A. baumannii, causing severe pulmonary dysfunction. A nebulized phage inhalation combined with intravenous administration of polymyxin B, amikacin, and fosfomycin successfully brought about measurable clinical improvements in 8 days. The clearance of XDR A. baumannii in sputum cultures, coupled with decreased partial pressure of carbon dioxide, substantial absorption of bilateral pulmonary lesions, reduced density of residual infiltrates, and decreased pleural effusion in the patient, collectively confirmed therapeutic efficacy. Our case indicate that bacteriophage-antibiotic therapy is promising to prevent the emergence of resistant mutants and enhance antibacterial efficacy in patient with similar infections.