肺炎克雷伯菌中质粒介导的AmpC酶的检测及基因型的研究  

On detection of plasmid-mediated AmpC β-lactamase and genotype in Klebsiella pneumoniae

作　　者：林云[1] 林平[2] 

机构地区：[1]台州医院,浙江临海317000 [2]台州学院医学院,浙江台州318000

出　　处：《中国卫生检验杂志》2010年第6期1411-1412,1428,共3页Chinese Journal of Health Laboratory Technology

基　　金：台州学院医学院重点课题(2009005)

摘　　要：目的:了解下呼吸道感染的肺炎克雷伯菌ESBLs和AmpC酶的产生情况及AmpC酶的耐药基因型。方法:采用VITEK-60型全自动细菌鉴定仪鉴定细菌,按NCCLS推荐的确证试验检测ESBLs;采用头孢西丁纸片扩散法筛选疑产AmpC酶阳性菌株,并通过酶粗提物头孢西丁三维试验、接合试验、PCR测序等实验分析该菌株的基因型。结果:97株肺炎克雷伯菌ESBLs阳性33株(34.02%);AmpC酶筛选阳性16株(16.49%),筛选阳性菌株经三维试验证实为AmpC阳性9株(9.28%);9株AmpC酶阳性菌株经接合试验得到9株接合子,经PCR测序证实此9株接合子与原菌株表型基本一致。9株AmpC酶阳性菌株均为ESBLs阳性菌株,基因型均未检出AmpC单独阳性株。AmpC酶阳性株的基因型:7株为DHA型,2株为CIT型。结论:下呼吸道分离的肺炎克雷伯菌ESBLs及AmpC酶产生率较高,AmpC酶以DHA基因型为主。产ESBLs和AmpC酶是肺炎克雷伯菌耐药的主要原因。Objective：To explore the formation of ESBL and AmpC β-Lactamase of K.pneumoniae in lower respiratory tract infections,and AmpC β-Lactamase genotypic resistance.Methods：Microbiological identification was performed with the VITEK 60 System and ESBLs were detected in accordance with the confirmatory test recommended by NCCLS.Suspected positive strains of AmpC β-lactamase were screened with cefoxitin disk diffusion.The genotypes were analyzed by cefoxitin three-dimensional test,conjugation test and PCR sequencing.Results：Of the 97 isolates,33（34.02%）were ESBLs positive,16（16.49%） were screened to be AmpC β-lactamase positive,of which 9（9.28%）were confirmed through the three-dimensional test.From them,9 conjugants were produced by conjugation,and confirmed to be much the same as the original phenotype by PCR sequencing.They were all ESBLs positive and no isolates of being only AmpC β-lactamase positive were detected.Among them,7 were DHA and 2 were CIT.Conclusion：K.pneumoniae isolated from lower respiratory tract has higher productivity of ESBLs and AmpC β-Lactamase and AmpC β-Lactamase is mainly of DHA genotype.The production of AmpC β-Lactamase and AmpC β-Lactamase is main reason for K.pneumoniae to be resistant to drugs.

关 键 词：AMPC酶 Β-内酰胺酶 肺炎克雷伯菌 基因型 下呼吸道感染 

分 类 号：R563[医药卫生—呼吸系统]