Genomic comparisons of multiresistant Pseudomonas aeruginosa isolates obtained from surgical intensive care unit

Objective To investigate the genetic differences and their relativity with multi-drug resistance of Pseudomonas aeruginosa isolated.Methods Forty-nine Pseudomonas aeruginosa isolates were characterized by antimicrobial susceptibility and four-enzyme (I-Ceu I,Spe I,Swa I,Pac I) pulsed-field gel electrophoresis (PFGE).Results 85.7% of the P.aeruginosa isolates were MDR strains.Strains with PFGE pattern A were all susceptible to amikacin and cefepime, but were resistant to levofloxacin and meropenem.Strains with PFGE Patterns H and P had resistance to 6-8 different kinds of antibiotics.Strains with PFGE Patterns I and J were susceptible to all antibiotics tested in this study.Strains with other PFGE Patterns had intermediate resistance.PFGE pattern A was the dominant pattern, which accounted for 61.2% of all P.aeruginosa strains, 100 % (2/2) in 2001, 65% (13/20) in 2002, 44.4% (8/18) in 2003 and 77.8% (7/9) in 2004.Conclusion Four-enzyme combined PFGE analysis is highly discriminatory for the subtyping of MDR P.aeruginosa isolates. Key words: Pseudomonas,aeruginosa; Custodial care; Genome,bacterial