Analyses on drug resistance phenotype of multi-drug resistant Pseudomonas aeruginosa and on antibacterial activity of combined antimicrobial agents / 解放军医学杂志

ABSTRACT

Objctive To investigate the zymogenic state and drug resistance of multi-drug resistant Pseudomonas aeruginosa (MDRP) for providing a laboratory basis of combined use of drugs against MDRP in clinical practice. Methods All isolates were isolated by routine procedures and identified by VITEK-2 automatic bacterial identification instrument. Following the CLSI instruction, doubling dilution in agar plates was performed for MIC detection. Results MDRP were 22.77% ( 86.96% for sputum) from 101 strains Pseudomonas aeruginosa, which were isolated from clinical specimens. Positive rates of MDRP producing metallo-?-lactmases were 91.3%, positive rates for producing induced Ampc and plasmid Ampc ?-lactamase were 52.17% and 21.74%, respectively. The ratio between Meropenem and Imipenem higher then 1 was 34.78%. The bacterial inhibitory rates of Polymyxin B and Imipenem were zero, that of Amikaein and Ceftaxidime were 4.35%, that of Ciprofloxacin and Cefoperazone/sulbactam were 43.48%, that of Pazufioxacin and Piperacillin/Tazobactam were 21.74% and 26.07%, and that of Meropenem was 47.83%. The combined use of Cefoperazone/sulbactam, Cefpirome, Piperacillin/Tazobactam with Amikacin resulted in bacteriostatic rate of 65.2%, 47.8%, 43.5%, respectively. Conclusoins MDRP is main micro-organism found in respiratory tract specimens. Drug resistance of MDRP is related to multiple drug-resistant mechanisms. Clinicians should first select enzyme inhibitory-drug (Cefoperazone/sulbactam or Piperacillin/Tazohaetam) with Amikacin or Polymyxin B to treat clinical MORP infection, and re-adjust the type of antibiotics rationally according to patients' symptoms, phenotype of the drug-resistant pathogen, the results of drug susceptibility test, and the effect on the patients.