Antimicrobial susceptibility ofpseudomonasaeruginosain CF patients before and after regular treatment with inhaled tobramycin

Aim: To evaluate antimicrobial susceptibility of Pseudomonas aeruginosa , isolated from CF patients before and after initiation of regular therapy with inhaled tobramycin. Methods: For the period of 2006–2013 we evaluated sputa from 118 CF patients (50 females and 68 males) aged 5 to 34 years of age. We evaluated the antimicrobial susceptibility towards 17 antimicrobials, according CLSI recommendations. Results: In the sputa of 70 patients(32 males and 38 females) a total of 102 isolates of P . aeruginosa were found. Age distribution was as follows: 42,1% of all children under 9 years of age, 57,9% for children aged 10 to 16 years and 86,9% for patients over 16 years of age. 68 out of 102 (66.7%) were susceptible to all 17 studied antimicrobials. Low resistance levels were found towards: imipenem (5.9%), meropenem (3.9%), amikacin (3.9%), gentamicin (7.8%), tobramycin (5.9%), netilmicin (13.7%) and ciprofloxacin (13.7%). In Bulgaria the first inhaled tobramycin regimens were introduced in 2007 and this treatment became regular in 2009. We divided the isolates before 2009 (64) and after 2009 (38). Significant reduction (p