Carbapenem-resistance mechanisms of multidrug-resistant Pseudomonas aeruginosa
Carbapenem-resistance mechanisms of multidrug-resistant Pseudomonas aeruginosa
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DOI：
10.1099/jmm.0.058354-0
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发表时间：
2013-09-01
影响因子：
3
通讯作者：
Vinas, Miguel
中科院分区：
文献类型：
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作者：
Fuste, Ester;Lopez-Jimenez, Lidia;Vinas, Miguel
多重耐药铜绿假单胞菌(MDRPA)的克隆性传播是世界范围内的一个主要问题。本研究的目的是探索MDRPA克隆对碳青霉烯类抗生素耐药的机制。分离自手术伤口、痰、尿和血培养。脉冲场凝胶电泳(PFGE)显示这些分离株的基因组高度同源性，并证实了一个属于O4型血清的地方性克隆的循环。用SDS-PAGE显示外膜蛋白(OMP)条带，用生物测定法测定美罗培南积累量，用聚合酶链式反应(PCR)检测整合子。在终浓度分别为10 mg L(-1)和40 mg L(-1)的乙酰氰基间氯苯肼(CCCP)和苯丙氨酸-β-萘胺(PA-BETA N)存在或不存在的情况下，研究了几种抗菌剂及其协同作用对泵的影响。在OMP电泳谱上，MDRPA显示外膜孔蛋白D(OprD)减少，聚合酶链式反应(PCR)显示存在1类整合子和编码氨基糖苷腺苷转移酶B(AADB)的盒。美罗培南在杆菌中的积累略高于在抗生素存在下形成的丝状细胞中的积累。外排泵MexAB-OprM和功能性Mexxy-OprM在所有分离株中均有过表达。
Clonal dissemination of multidrug-resistant Pseudomonas aeruginosa (MDRPA) is a major concern worldwide. The aim of this study was to explore the mechanisms leading to the carbapenem resistance of an MDRPA clone. Isolates were obtained from a surgical wound, sputum, urine and a blood culture. Pulsed-field gel electrophoresis (PFGE) showed high genomic homogeneity of these isolates and confirmed the circulation of an endemic clone belonging to serotype O4. Outer membrane protein (OMP) bands were visualized by SDS-PAGE, meropenem accumulation was measured in a bioassay and integrons were detected by PCR. Efflux pumps were studied for several antimicrobial agents and synergic combinations thereof in the presence or absence of both carbonyl cyanide m-chlorophenylhydrazone (CCCP) and Phe-Arg-beta-naphthylamide (PA beta N) at final concentrations of 10 and 40 mg l(-1), respectively. On OMP electrophoretic profiles, MDRPA showed a reduction of outer membrane porin D (OprD) and PCR demonstrated the presence of a class 1 integron with a cassette encoding aminoglycoside adenyltransferase B (aadB). Meropenem accumulation was slightly higher in bacilli than in the filamentous cells that formed in the presence of antibiotics. Overexpression of the efflux pump MexAB-OprM and a functional MexXY-OprM were detected in all isolates.