医院感染中大肠埃希菌耐药质粒的同源性分析
Homology analysis of resistant plasmids in nosocomial infection Escherichia coli
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摘要:目的 了解不同医院不同科室大肠埃希菌耐药质粒流行状况, 分析菌株间的同源性, 为控制院内感染流行提供依据。方法 采用药敏分析、质粒消除实验、质粒图谱及限制性内切酶图谱等技术对医院感染大肠埃希菌耐药质粒进行同源性分析。结果 从2家省级医院不同科室196份标本中分离到E.coli25株, 分离率为12.8%。检出菌对抗生素的耐药率为76.0%, 有28.0%的菌株仅耐1种药, 对3种及3种以上抗生素耐药的有32.0%。在25株分离菌中19株检出质粒, 检出率为76.0%。所有菌株均有24.8 kb质粒, 提示该质粒是医院致病性大肠埃希菌的流行质粒。对13株携带质粒的耐药大肠埃希菌进行质粒消除, 除1株菌的耐药性始终未变化外, 其余12株的耐药性有不同程度地改变, 其中7株耐药性全部消失, 5株仅有部分改变。大小相同的耐药质粒经EcoR I酶切后发现同一科室菌株的耐药质粒有相同的DNA片段, 不同科室菌株间也有相似的酶切图谱。结论 医院病房存在流行耐药质粒, 不同科室有不同的质粒流行, 各科室菌株间有一定的同源性。Abstract:Objective To understand the epidemic condition about the resistant plasmids and their homology of the E.coli obtained from two hospitals in Gansu province.Methods The antibiotic sensitivity test, plasmid elimination, plasmidpro-file, restriction endonuclease profile were used in analyzing tho E.coli resistant plasmids.Results 25 strains of E.coli were isolated from 196 samples in two different hospitals, the isolation r ate was 12.8%.76.0% isolates were resistant to the eight common antibiotics in different degree.Only 28.0% strains were just resistant to one antibiotics, the multi-rcsistant strains amount for 32.0%.There were 19 isolates car ried plasmids(76.0%).The results of plasmid elimination showed 12 strains carried resistant plasmid, and the one with 24.8kb was popular plasmid.The endnuclease profiles revealed that the same source strains had certain homology, there were similiarendonuclease profiles among strains in different wards.Conclusion The popular plasmids in different wards had certain homology, and they can be transferred among different strains of bacteria.
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