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目的 研究临床分离的致肾盂肾炎大肠杆菌粘附基因群DNA的多态性。方法 以血凝试验 (MRHA)为基础 ,分别用编码P菌毛主体结构和尖端粘附素的基因探针 ,采用DNA杂交方法对临床分离的 95株尿源性大肠杆菌的粘附基因群进行分析。结果MRHA +++～ ++++占 37 9% (36株 ) ,++占 32 6 % (31株 ) ,MRHA阴性占 2 9 5 % (2 8株 )。菌落原位杂交和DNA斑点杂交试验在MRHA +++～ ++++,++和阴性菌株中两个探针均为阳性的分别为 91 7%、9 7%和 2 1 4% ;在MRHA ++和阴性菌株中单一探针阳性的分别为 6 4 5 %和 35 7%。同时 ,选 10株MRHA ++++大肠杆菌提取染色体DNA ,经EcoRⅠ酶切后Southern杂交进行限制性片段长度多态性分析 ,同源性DNA片段大小不一 ,杂交信号的强弱程度也不同。结论 提示致肾盂肾炎大肠杆菌pap粘附基因群的多样性。
Objective To study the polymorphism of DNA isolated from clinical isolates of pyelonephritis caused by E. coli. Methods Based on the hemagglutination test (MRHA), 95 clinical isolates of urinary E.coli were analyzed by DNA hybridization with gene probes encoding the main structure of P pilus and apheresis, analysis. Results MRHA +++ ~ ++++ accounted for 37 9% (36 strains), ++ accounted for 32 6% (31 strains), MRHA negative accounted for 295% (28 strains). The results of colony in situ hybridization and DNA dot blot test were 91.7%, 97% and 214% respectively in MRHA +++ ~ ++++, ++ and negative strains; Single probes positive for MRHA ++ and negative strains were 64.5% and 35.7%, respectively. At the same time, 10 strains of MRHA ++++ were selected to extract chromosomal DNA. Restriction fragment length polymorphism analysis was performed by Southern blotting with restriction endonuclease EcoR Ⅰ. The homologous DNA fragments were different in size and intensity of hybridization signal . Conclusion The results suggest that the diversity of pap adhesion gene cluster in pyelonephritis.