老年住院患者肺炎克雷伯菌临床分离株多位点可变数目串联重复序列基因分型特征分析

Genotyping of Klebsiella Pneumonia Strains Isolated from Eldly Inpatients by Multiple-locus Variable-number Tandem-repeat Analysis

目的探讨老年住院患者肺炎克雷伯菌分离株多位点可变数目串联重复序列分析的基因分型特点。方法收集解放军总医院南楼临床部老年住院患者肺炎克雷伯菌临床分离菌株184株,提取基因组DNA,采用多重PCR和毛细管电泳对7个位点进行分析,利用Bio Numerics 5.1软件进行聚类分析。结果 184株肺炎克雷伯菌临床分离株共产生139种基因型,呈现明显的基因多态性;聚类分析结果显示,全部菌株可分为3个基因群,其中Ⅰ群包含93.06%的菌株。结论本医疗中心老年住院患者的肺炎克雷伯菌临床分离株具有明显的优势菌群,其感染来源仍以院内感染为主。

Objective To investigate the genotype of klebsiella pneumonia strains isolated from eldly inpatients by multiple-locus variable-number tandem-repeat analysis. Methods Totally 184 klebsiella pneumonia strains,isolated from eldly inpatients,were collected,and their genome DNA were extracted. The polymorphism of 7 variable-number tandem-repeat locus in the DNA samples was analyzed by multiple primers polymerase chain reaction and capillary electrophoresis. The clustering analysis of genotyping was carried out with the Bio Numerics 5. 1 software. Results A total of 139 genotypes were identified in 184 klebsiella pneumonia clinical strains,showing obvious genetic polymorphisms. With clustering analysis of genotypes,all the strains were categorized into three gene clusters（ genogroups Ⅰ,Ⅱ,and Ⅲ）. The genogroup Ⅰ was the biggest cluster,containing 93. 06% of the isolated strains. Conclusion There was a predominant cluster in the klebsiella pneumonia strains isolated from eldly inpatients in our center,and the major source of klebsiella pneumonia infection remained the nosocomial infection.