Objective: Pseudomonas aeruginosa strains which are found widely in the hospital setting, frequently lead to infections particularly in intensive care units (ICU). Since they are frequently resistant to several antibiotics and disinfectants, their morbidity and mortality are quite high. The aim of this study was to evaluate the antimicrobial susceptibility of P. aeruginosa strains isolated from clinical specimens processed at Microbiology Laboratory of Afyon Kocatepe University ANS Hospital, Turkey.

Materials and Methods: A total of 123 isolates were enrolled from hospitalised patients during 2007 January –2008 March period. Susceptibility to amikacin (AK), tobramycin (TOB), ciprofloxacin (CIP), ofloxacin (OFX), ceftazidime (CAZ), ceftriaxon (CRO), cefotaxime (CTX), cefepime (FEP), cefoperazon-sulbactam (SCF), piperacillin-tazobactam (TZP), aztreonam (ATM), imipenem (IPM) and meropenem (MEM) were investigated by standard disk-diffusion methodology according to CLSI criteria.

Results: Isolates were obtained most frequently from wound specimens and respiratory samples (i.e. sputum, tracheal aspirate); followed by blood and urine samples. Most of the strains (45.5 %) were isolated from patients stayed in ICU. AK and TOB were the most susceptible agents against P. aeruginosa strains, resistance rates being 4.9%. The resistance rates for MEM and IPM were 26% and 26.8%, respectively. The resistance rates for cephalosporins were over 70%, for ATM was 78.9% while CIP resistance was 33.3%. However, the resistance rates were higher among the strains isolated from ICU; 46.4% for carbapenems, 91.1% for ATM and 47.5% for CIP.

Conclusion: High antibiotic resistance rates of P. aeruginosa isolated in our hospital was of notice. The treatment problems encountered in P. aeruginosa infections might be attributed to the high rates of resistance to cephalosporins. Significantly high carbapenem resistance rate among ICU isolates deserves special attention.