Multi-drug Resistant Genes of Pseudomonas aeruginosa Clinical Strains

OBJECTIVE To analyze the multi-drug resistant genes(genes encoding extended-spectrum β-lactamases,outer membrane protein gene oprD2,aminoglycoside-modifying enzyme genes,sulfonamides and disinfectant-resistance gene and plasmid-mediated quinolone resistance gene) of Pseudomonas aeruginosa clinical strains.METHODS The drug-resistance to 15 antibiotics was detected by the disc agar diffusion(DAD) and microdilution broth method in 32 P.aeruginosa strains isolated from Jun to Dec 2006.Twenty-eight related drug-resistant genes and outer membrane protein gene oprD2 were examined by PCR method.RESULTS The resistance rate of 32 P.aeruginosa strains to amikacin,ceftazidime,ciprofloxacin,cefepime,cefoperazone/sulbactam,imipenem,meropenem,levofloxacin,piperacillin/tazobactam,aztreonam and piperacillin were 9.4%,25%,59.4%,68.7%,68.8%,78.1%,81.1%,81.3%,84.4% and 94.4%,respectively,and that to others antibiotics were 100%.The detective rate of aminoglycoside-modifying enzyme genes(aac(6′)-Ⅱ,aac(3)-Ⅱ,aac(6′)-Ⅰ,aph(3′)-Ⅵ,ant(3″)-Ⅰ and aac(3)-Ⅰ) were 68.8%,62.5%,21.9%,9.4%,9.4% and 6.3%,and the genes encoding extended-spectrum β-lactamases(blaFOX,blaIMP,blaVIM and blaDHA) were 37.5% 15.6% 6.3% and 9.3%,respectively.Twenty-two(68.8%) of them were detected in oprD2 and 9(28.1%),but positive in qacEΔ-sul1 gene.CONCLUSIONS The detective rate of aminoglycoside-modifying enzyme genes,extended-spectrum β-lactamases genes and the loss rate of outer membrane protein gene oprD2 are high in these 32 multi-drug resistant P.aeruginosa clinical strains.