| 徐建国,程伯鲲,吴艳萍,黄力保,邓庆东,赖心河,刘秉阳,罗兴祖,李惠芬.产志贺样毒素且具侵袭力的大肠杆菌的研究[J].Chinese journal of Epidemiology,1994,15(6):333-338 |
| 产志贺样毒素且具侵袭力的大肠杆菌的研究 |
| A new diarrhea pathogen: Entero-SLTs-producing and invasive Escherichia coli was over-looked as normal flora E.coli |
| Received:February 15, 1994 |
| DOI： |
| KeyWord: 大肠杆菌 志贺样毒素 |
| English Key Word: Escherichia coli Shiga-like-toxin |
| FundProject: |
| Author Name | Affiliation | | Xu Jianguo | Department of Microbiology, Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing P R China | | Cheng Bokun | Department of Microbiology, Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing P R China | | Wu Yanpinq | Department of Microbiology, Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing P R China | | 黄力保 | Department of Microbiology, Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing P R China | | 邓庆东 | Department of Microbiology, Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing P R China | | 赖心河 | Department of Microbiology, Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing P R China | | 刘秉阳 | Department of Microbiology, Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing P R China | | 罗兴祖 | 北京市西城区卫生防疫站 | | 李惠芬 | 北京市西城区卫生防疫站 |
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| Abstract: |
| 我国临床腹泻病人粪便标本中,约有60%检不出任何已知病原,而能分离出几乎纯培养的大肠杆菌。这些大肠杆菌过去被误认为是肠道正常菌群。我们对在北京西城区三个医院从腹泻病患者粪便标本中分离的172株所谓正常大肠杆菌,进行了质粒DNA、Hep-2细胞粘附试验,和10种DNA探针分析。结果发现这些所谓的肠道正常大肠杆菌并不正常,其中44%可鉴定为致泻性大肠杆菌,包括EHEC16株,占所检查菌株的9.3%;EPEC8株,占所检查菌株的4.7%;EAggEC11株占6.4%。还有54株菌对Inv、SLT1或SLT2探针同时呈阳性反应,占所检查菌株的31.4%。我们认为对Inv、SLT1或SLT2探针同时呈阳性反应的菌株是一种尚未在国际上报道的致泻性大肠杆菌,将其命名为“产志贺样毒素且具侵袭力的大肠杆菌”(Entero-SLTs-producing and invasive E.coli ESIEC)。与EIEC不同,ESIEC虽能侵入Hep-2细胞,但不具有ipaB基因,编码侵袭力的基因与EIEC有所不同。该类菌株虽对Hep-2细胞呈现集聚性粘附现象,但不与肠集聚性大肠杆菌(EAggEC)探针起反应;产生肠毒素,细菌滤过液对Hep-2细胞有致死作用。ESIEC占所检查菌株的31.4%,在我国有可能是一种比ETEC、EIEC、EPEC、EHEC发病率都高的致泻性大肠杆菌。 |
| English Abstract: |
| In clinical laboratories of Beijing, China, no known entero-pathogen but almost pure E. coli strains could be isolated from more than 60% fecal samples of diarrheal patients, which had been recognized as normal flora E. coli and dismissed. We suspected that some of the so-called normal flora E. coli strains might be virulent. To prove our idea, We collected 172 strains of E. coli isolated from diarrheal patients from whom no other enteric bacterial pathogens had been identified, including EPEC, EIEC, ETEC. With plasmid DNA analysis, Hep-2 cell adherence assay and 10 DNA probe hybridization, we found that the so-called normal flora E. coli was abnormal, 44% of them were virulent, of which 16 (9.3) were EHEC, 8 EPEC (4.7%), 11 EAggEC (6.8%). Fifty-four of 172 strains were hybridized with INV and SLT1 or SLT2 probes, which had never been reported. These strains could invade Hep-2 cells, but were lack of ipaB gene, a key gene of invasiveness gene cluster of Shigella species and EIEC. The aggregative adherence to Hep-2 cells was observed, but the strains were not hybridized with EAggEC specific DNA probe. The purified toxin protein and cell filtrate were toxic to vero cells. Based on the data obtained, we believed that this is a new category of diarrhea-genic E. coli, named as entero-SLTs-producing and invasive E. coli (ESIEC). ESIEC occupied 31.4% of the strains tested, the isolation of it was probably higher than those of ETEC, EPEC in P R China. |
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