Susceptibility patterns and cross resistances of antibiotics against <it>Pseudomonas aeruginosa</it> in a teaching hospital of Turkey

Abstract

Abstract Background Pseudomonas aeruginosa is the third most common pathogen responsible for nosocomial infections and the prevalence of multiple resistant isolates has been increasing. Ninety-nine clinical isolates were studied in order to assess the current levels of susceptibility and cross-resistances of widely used antipseudomonal antibiotics against P. aeruginosa and to determine some resistance mechanisms by phenotypic methods. Methods MICs of isolates for nine antipseudomonal antibiotics were determined by the E test method. Results Thirty-six percent of isolates were resistant to more than one group of antibiotics. The rates of susceptible isolates were ciprofloxacin 75%, amikacin 73%, ceftazidime 65%, meropenem 63%, imipenem 63%, piperacillin/tazobactam 60%, cefoperazone/sulbactam 59%, cefepime 54% and tobramycin 44%. The majority of carbapenem resistant isolates were susceptible to ciprofloxacin and amikacin. Conclusion Ciprofloxacin seems to be the most active agent against P. aeruginosa followed by amikacin in our unit. The usefulness of combinations of these antibiotics and β-lactams should be tested in treating multi-drug resistant P. aeruginosa.