耐亚胺培南铜绿假单胞菌β-内酰胺酶分布分析

Distribution of β-lactamases among clinical imipenem-resistant pseudomonas aeruginosa

目的研究耐亚胺培南(IMP)铜绿假单胞菌(PAE)对常用抗菌药物的耐药情况与β-内酰胺酶携带情况。方法采用琼脂稀释法、K-B纸片法进行药物敏感试验,用双纸片协同(DDST)法筛选产金属酶的菌株,用聚合酶链(PCR)法进行基因型检测和分析。结果 2008年68株耐亚胺培南铜绿假单胞菌中,DDST阳性12株;2009年50株耐亚胺培南铜绿假单胞菌中,DDST阳性11株;2008年465株PAE中K-B法对IMP不敏感率为14.8%、MIC法为14.6%,2009年285株PAE中K-B法对IPM不敏感率为18.9%,MIC法为17.5%;基因检测,各基因型的分布比例为IMP 2.5%、VIM 5.9%、GIM 0.8%、KPC 4.2%、OXA-10 28.8%、OXA-2 7.6%、OXA-1 1.6%。结论临床常用抗铜绿假单胞菌药物耐药比例升高,IMP耐药的PAE多为多药耐药株和泛耐药株,OXA型ESBLs基因携带率较高。

OBJECTIVE To investigate the antimierobials susceptibility and prevalence of β-lactamases for imipenem （IMP）-resistant Pseudomonas aeruginosa （PAE） . METHODS Drug susceptibility test was performed by agar-dilution and K-B method. Mello-β-1actamases （MBL） were detected by double disc synergistic test （DDST）. Resistance determinants were screened by PCR amplification using specific primer for each kind of enzymes. RESULTS 12 and 11 isolates were positive for MBL DDST among 68 and 50 non-duplicated strains of clinical imipemen-resistant P. aeruginosa isolated in 2008 and 2009, respectively. The resistant rate of clinical P. aerugi- nosa isolates was 14.6% and 1 7.5 % according to MICs. Resistance genes distributed as follows：IMP 2.5 %, VIM 5.9%, GIM0.8%, KPC4.2%, OXA-10 28.8%, OXA-2 7.6%, OXA-1 1.6%. CONCLUSlON The resistance rate of common used antibiotics is increasing in clinical P. aeruginosa isolates. Imipemen resistant P. aeruginosa isolates always exhibit multi-drug resistance （MDR） or even pan-drug resistance （PDR） phenotype.