Antimicrobial activity of tobramycin against Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis

<p>In patients with cystic flbrosis, lower respiratory tract infections are characterized by a steadily recurrent and severe course. Recently, inhaled tobramycin has been successfully used to treat Pseudomonas aeruginosa-iniucei diseases in children aged over 6 years. In this trial, the E-test (Liofilchem, Italy) was employed to determine the antimicrobial activity of tobramycin against 40 P. aeruginosa strains isolated from 25 patients with cystic fibrosis in the period 2005—2009. At the same time MIC50 and MIC90 were 0,75 and 3,0 mg/ml, respectively. No relationship to patient age (and duration of P. aeruginosa colonization) was established. Tobramycin showed high activity in vitro against P. aeruginosa strains isolated from the patients with cystic flbrosis. The activity was related to the morphology of a strain and previous treatment with inhaled tobramycin. When initiating its inhalation treatment in cases of inoculation of moderately susceptible or resistant P. aeruginosa strains (according to the CLSI criteria), it is necessary to interpret their susceptibility test results by following the MENSURA Group criteria.