临床分离133株肺炎克雷伯菌耐药机制和基因分型研究

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。

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

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.