临床分离133株肺炎克雷伯菌耐药机制和基因分型研究

Mechanism of Drug Resistance and the Genotype of 133 Klebsiella pneumoniae Clinical Isolates

目的研究临床分离肺炎克雷伯菌的耐药机制及基因多态性。方法用WHONET5.4分析菌株药敏情况。PCR检测菌株I类整合酶、ISCR和ESBLs基因;ERIC-PCR检测基因型,SPSS分析其多态性。结果除亚胺培南和美洛培南,产ESBLs菌的耐药率明显高于不产ESBLs菌(P<0.005)。对I类整合酶、ISCR、blaTEM、blaSHV、blaCTX-M,88株产ESBLs株的阳性率分别为59.1%、43.2%、69.3%、4.5%、45.5%;45株不产ESBLs株的阳性率分别为40.0%、15.6%、22.2%、4.4%、6.7%。根据指纹图谱把133株肺炎克雷伯菌分为126种,经SPSS系统聚类分析,归为20个大类。结论南方医院产ESBLs肺炎克雷伯菌主要是CTX-M基因型,整合子和ISCR可以共存;ERIC-PCR是一种效果较好的基因分型方法,该院肺炎克雷伯菌呈散发存在。

Objective To study the mechanism of drug resistance and the genetic polymorphism of Klebsiella pneumoniae obtained from the clinical samples. Methods Drug resistance was analyzed by WHONET5.4. Bacterial Class I integrase, ISCR and ESBLs （extended-spectrum β-lactamase） were analyzed by PCR. The homology was tested by enterobacterial repetitive intergenic consensus PCR （ERIC-PCR）. The software SPSS was used for data analysis. Results The rate of drug resistance, except Imipenem and Meropenem, of the ESBL-producing strains was significantly higher than the non-ESBL producing strain （P〈0.005）. Among the 88 ESBL-producing strains, the positive rate of Class I integrase, ISCR, blaTEM, blaSHV, and blaCTX-M was 59.1%, 43.2%, 69.3%, 4.5% and 45.5%, respectively. In contrast, the positive rate of Class I integrase, ISCR, blaTEM, blaSHV, and blaCTX-M was 40.0%, 15.6%, 22.2%, 4.4% and 6.7%, respectively, for the 45 non-ESBLs producing strains. These 133 bacterial isolates were further grouped into 20 groups with 126 genotypes. Conclusion CTX-type is the predominant genotype of ESBL-producing Klebsiella pneumoniae in our hospital. Integron can exist with ISCR. ERIC-PCR is a useful method in the genotyping of KlebsieUa pneumoniae. There is no nosocomial infection of Klebsiella pneumoniae in our hospital.