Antimicrobial resistance characteristics and mechanisms of imipenemresistant Pseudomonas aeruginosa

Abstract:

ObjectiveTo investigate antimicrobial resistance characteristics and  mechanisms of imipenemresistant Pseudomonas aeruginosa (P. aeruginosa) isolated from clinical specimens.MethodsBacterial strains were identified by BD Phoenix 100 automatic microbial analysis system, antimicrobial susceptibility testing  was performed by KirbyBauer method; Carbapenemase genes (IMP, VIM, OXA,GES) and outer  membrane protein gene oprD2  were detected by polymerase chain reaction.ResultsResistant rates of imipenemresistant P. aeruginosa strains to amikacin was the lowest (8.33%); resistant rates to gentamicin and tobramycin were<20%； resistant rates to the third and fourth generation  cephalosporins,aztreonam, meropenem,compound sulfamethoxazole and minocycline were all>60%, and all strains were resistant to ampicillin /sulbactam.The positive rate of OXA17 gene was 2.78%（n=1）， deletion rate of oprD2 was 38.89%,the other drugresistant genes were not detected. ConclusionExcept aminoglycosides, resistance of imipenemresistant P. aeruginosa to other antimicrobial agents is serious; resistance of P. aeruginosa to imipenem may be due to  lacking of OprD2 and production of carbapenemases.