铜绿假单胞菌产AmpC酶和ESBLs的研究

Study on AmpC beta-lactamase and ESBLs in pseudomonas aeruginosa

目的:研究我院多重耐药铜绿假单胞菌产ESBLs与AmpC酶的耐药表型和基因型,了解两种酶的分布情况。方法:用K-B法进行ESBLs试验,3-氨基苯酚硼酸(APB)纸片增强法检测AmpCβ-内酰胺酶表型阳性菌;IPM和多底物纸片法进行诱导产AmpC酶定性试验;PCR检测AmpC酶和ESBLs基因并进行测序分析。结果:70株菌检测出产AmpC酶阳性菌51株,其中33株诱导产AmpC酶试验阳性,诱导率依次氨曲南和头孢他啶-克拉维酸>哌拉西林>头孢他啶>头孢吡肟>头孢噻肟>头孢噻肟-克拉维酸,1株扩增出DHA型AmpC酶,经测序为DHA-1型;ESBLs阳性1株,扩增为tem基因。结论:我院存在产ESBLs与AmpC酶的多重耐药铜绿假单胞菌。

Objective： To study the phenotype and genic type of AmpC beta-lactamase and ESBLs in pseudomonas aeruginosa. nethods：K-B disc method was used to detect ESBLs. AmpC beta-lactamase was detected on the basis that AmpC beta-lactamase could be inhibited by 3-aminophenylbooronic acid （APB）. Imipenem and multisubstrates were used to detect the inducible AmpC β-1actamase, PCR was used to detect genes of AmpC and ESBLs, and DNA sequencing was adopted to analyze genes. Results： 1 strain and 51 strains showed ESBLs and AmpC positive phenotype. Among them, the specific band of AmpC （dha, 1 strain） and ESBLs（tem, 1 strain） were detected. The sequence result was DHA-1. From the 51 AmpC positive strains of P. aeruginosa, 33 strains produced the inducible AmpC β-1actamase. The inducible rates were aztreonam, ceftazidime-clavulanate 〉 piperacillin 〉 cefepime 〉 ceftazidime 〉 cefotaxime 〉 cefotaxime-clavulanate. Conclusion： There are multidrug resistant P. aeruginosa strains in PLA general hospital.