Development of resistance to imipenem among nosocomial isolates of Pseudomonas aeruginosa

Pseudomonads are ubiquitous organisms which are resistant to many antibiotics. Resistance can develop during therapy by the induction of antibiotic-inactivating enzymes (e.g. beta-lactamases), chromosomal mutations or the transfer of R plasmids from a resistant organism to a susceptible one. Imipenem, a beta-lactam antibiotic which is resistant to most beta-lactamases, was first marketed in Turkey in January 1993 and has been used routinely since then to treat infectious diseases. In this study we determined the development of resistance to imipenem in nosocomial Pseudomonas aeruginosa strains isolated before and after this antibiotic was marketed.