ANTIBIOTIC-TREATMENT OF EXPERIMENTAL PSEUDOMONAS-AERUGINOSA PNEUMONIAIN GUINEA-PIGS - COMPARISON OF AEROSOL AND SYSTEMIC ADMINISTRATION

Pseudomonas aeruginosa pneumonia is associated with high mortality des pite appropriate systemic antibacterial therapy. To examine the effect s of aerosolized tobramycin on experimental P. aeruginosa pneumonia, g uinea pigs were assigned to two main groups: a study group, in which P . aeruginosa was instilled into the tracheal lumen, and a control grou p, in which normal saline was instilled. Each group was then subdivide d according to treatment: normal saline or tobramycin by intramuscular injection, normal saline or tobramycin by aerosol, or normal saline o r tobramycin via both aerosol and intramuscular injection. Compared wi th either intramuscular or aerosolized tobramycin, the combination of aerosol plus intramuscular tobramycin achieved slightly higher surviva l, total eradication of P. aeruginosa from lungs, and a significant fu rther reduction of lung inflammatory changes. Adding aerosolized tobra mycin to systemic tobramycin in the treatment of experimental P. aerug inosa pneumonia enhanced eradication of P. aeruginosa and mitigated pu lmonary inflammatory changes.