大肠埃希菌、克雷伯菌中质粒AmpC酶的流行分布  

Distribution of plasmid-mediated AmpC β-lactamase in Escherichia coli and Klebsiella spp

作　　者：李轶[1] 蒋燕群[1] 汤瑾[1] 王坚镪[1] 李桂兰[1] 

机构地区：[1]上海交通大学附属第六人民医院检验科,上海200233

出　　处：《检验医学》2006年第5期517-520,共4页Laboratory Medicine

摘　　要：目的了解我院大肠埃希菌、克雷伯菌中质粒AmpC酶的流行分布及其基因型特征。方法对1 935株大肠埃希菌、克雷伯菌进行了AmpC酶纸片扩散法筛选试验(头孢西丁≤18),对筛选阳性株分别进行三维试验、多重聚合酶链反应(PCR)、等电聚焦电泳(IEF)、接合试验、PCR及测序,以确定表型及基因型。结果1 935株细菌中,纸片筛选、三维试验、多重PCR的阳性数分别为327、85、54株;13株产C IT群质粒AmpC酶细菌有4株接合试验阳性;IEF证实这4株细菌均产生等电点为9.0、可以被氯唑西林抑制而不能被克拉维酸抑制的β-内酰胺酶。结论我院大肠埃希菌、克雷伯菌中质粒AmpC酶的阳性率为2.79%(54/1 935)。基因型为DHA群和C IT群2类。Objective To investigate the phenotype, genotype and distribution of plasmid-mediated AmpC β-laetamases in Escherichia coli and Klebsiella spp. Methods 1 935 Escherichia coli and Klebsiella spp were detected by standard disc diffusion method as screen test for AmpC lactamase. Three-dimensional extract test, multiplex polymerase chain reaction （PCR）, isoelectric focusing analysis （IEF）, conjugation, PCR and sequencing were performed on positive strains to determine the phenotype and genotype of AmpC β-1actamases. Results 327,85,54 strains were positive by standard disc diffusion, three-dimensional extract test and multiplex PCR respectively. 4 of 13 strains could transfer cefoxition resistance to the recipient. IEF proved that they produced a [3-1actamase whose isoelectric point （ pI ） was 9.0 and could be inhibited by cloxacillin and not by clavulnate. Conclusions 54 of 1 935 （2.79%） clinical isolates of our hospital harboured plasmid-mediated AmpC β-1actamases including DHA like and CIT like ampC genes.

关 键 词：质粒 AMPC酶 CIT群 DHA群 

分 类 号：Q782[生物学—分子生物学]