奇异变形杆菌中质粒携带的碳青霉烯酶基因型别的研究  

Analysis of carbapenemase genotypes of carbapenem-resistant Proteus mirabilis strains clinically isolated from 2009 to 2012

作　　者：胡丽庆[1] 王盛[1] 史煜波[1] 翁幸鐾[1] 

机构地区：[1]宁波市第一医院检验科,315000

出　　处：《中华微生物学和免疫学杂志》2013年第6期416-420,共5页Chinese Journal of Microbiology and Immunology

基　　金：浙江省医药卫生科学研究基金（2011KYB099）

摘　　要：目的研究本地区近4年临床分离的非重复碳青霉烯类耐药的奇异变形杆菌可能存在的碳青霉烯类酶基因型别。方法回顾分析2009到2012年临床分离奇异变形杆菌的资料筛选出非重复的碳青霉烯类抗生素耐药的菌株15株；用浓度梯度法（E-试条法）检测其对亚胺培南（IPM）、美罗培南（MEM）、厄他培南（ETP）、环丙沙星（CIP）、阿米卡星（AK）和米诺环素（MIN）的MIC值；Hodge试验进行产碳青霉烯酶的确认，同时对试验菌株进行耐药基因的PCR扩增检测及测序，对阳性扩增菌株的质粒提取物与叠氮钠耐受的敏感态大肠埃希菌J53（E．coliJ53）进行电转化，并对电转化后的菌株进行目标基因的PCR扩增及碳青霉烯类抗生素MIC值的检测。结果2009到2012年，筛选到15株耐碳青霉烯类抗生素耐药的菌株；IPM、MEM、ETP的耐药率均为100％，CIP的耐药率为86．7％（13／15），AK的耐药率为33．3％（5／15），MIN的耐药率为80％（12／15）；15株细菌中Hodge试验阳性7株，blaKPC基因阳性11株，经测序检测确认为blaKPC-2型；11株blaKPC基因阳性菌株的质粒提取物经电转化大肠埃希菌J53，使转化子大肠埃希菌J53对亚胺培南、美洛培南和厄他培南的MIC值增高2～64倍，PCR扩增转化子大肠埃希菌J53bla。基因均阳性。结论本地区对碳青霉烯类抗生素耐药的奇异变形杆菌，对阿米卡星的耐药率相对较低。其碳青霉烯酶的基因型主要为位于质粒上的6如眦。基因型，易于在菌株间流行，临床应引起高度重视。Objective To investigate the clinical distribution and the drug resistance of carbapenem- resistant Proteus mirabilis strains isolated from 2009 to 2012 ; and to study carbapenemase genotypes of the iso- lates. Methods A total of 15 non-repetitive carbapenem-resistant Proteus mirabilis strains were selected from 422 Proteus mirabilis strains isolated from Ningbo First Hospital during January 2009 to December 2012. The minimal inhibitory concentrations （MIC） of 6 antibacterial agents, including imipenem （IPM）, meropenem （MEM）, ertapenem （ETP）, ciprofioxacin （CIP）, amikacin （AK） and minocycline （MIN）, against 15 iso- lates were determined by E-test. The modified Hodge test （MHT） was used to detect the carbapenemase production in isolates. The PCR assay was performed to detect drug resistance genes of blctKPC, blaNoM-1, blaGEs, blasME, blaiMi.l/NmcA and b/asHv.3s. Plasmids were extracted from the blaKPc-positive strains and then transformed into Escherichia coli J53 strains by electroporation. The transformed and untransformed Escherichia coli J53 strains were tested for MIC values and blaxpc gene by E-test and PCR respectively. Results The resistance rates of the 15 carbapenem-resistant Proteus mirabilis strains to IPM, MEM, ETP, CIP, AK and MIN were 100%, 100%, 100%, 86.7% （13/15）, 33.3% （5/15） and 80% （ 12/15）, respectively. 7 out of 15 strains were Hodge test positive, and 11 strains were b/aKPC_2 positive. Results of PCR amplification showed that the transformed Escherichia coli J53 strains, whose MIC values to IPM, MEM, and ETP were increased by 2 to 64 times, were blaKpc-2 gene positive. Conclusion The carbapenem-resistant Proteus mirabilis strains in this study were resistant to many commonly used antibiotics, however, the resistance rates to AK were relatively low. The dominant carbapenemase genotype was blaKPC-2 carried by the plasmid. Attention should be paid to its easily transmissible feature among the strains in clinic.

关 键 词：奇异变形杆菌 blaKPC PCR 质粒 电转化 

分 类 号：R446[医药卫生—诊断学]