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首页> 外文期刊>Infection and immunity >Enterotoxigenicity of Enteropathogenic Serotypes of Escherichia coli Isolated from Infants with Epidemic Diarrhea
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Enterotoxigenicity of Enteropathogenic Serotypes of Escherichia coli Isolated from Infants with Epidemic Diarrhea

机译：从流行性腹泻婴儿中分离到大肠杆菌的肠道致病血清型的肠毒力

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Enteropathogenic serotypes of Escherichia coli which have been incriminated by epidemiological evidence as responsible for epidemics of acute diarrhea in infants are often found to be nontoxigenic when tested by conventional systems such as Y1-adrenal, Chinese hamster ovary, and suckling mouse assays. Twelve such strains, representing four different enteropathogenic serotypes, were examined for their capacity to elaborate toxic materials which alter water transport. Ultrafiltration fractions prepared to contain either a high-molecular-weight, heatlabile or a low-molecular-weight, heat-stable form of toxin from each strain were perfused through rat jejuna in graded concentrations ranging from 100 μg to 0.1 ng/ml. Ten of the twelve enteropathogenic strains produced one or both toxin forms that induced water secretion at concentrations of 1 to 10 ng/ml. Values in this range are considered indicative of clinically significant enterotoxigenicity in this assay system, and toxins from well-documented toxigenic strains examined in this study were active at these same concentrations. Similar preparations from ten control strains from healthy persons were either inactive or evoked water secretion only at concentrations of 10 to 100 μg/ml. These observations suggest that enteropathogenic serotypes of E. coli isolated from epidemics of infantile diarrhea produce diarrhea by elaborating potent heat-labile and heat-stable toxin forms which alter water transport but which are inactive in conventional assay systems. The manner in which these toxins differ either quantitatively or qualitatively from those which stimulate the conventional test systems is unknown.
机译：流行病学证据表明，大肠杆菌的肠道致病血清型是造成婴儿急性腹泻流行的原因，当通过常规系统（例如Y1肾上腺，中国仓鼠卵巢和哺乳小鼠试验。检查了代表四种不同肠致病血清型的十二个这种菌株的精制改变水运输的有毒物质的能力。通过大鼠空肠以浓度范围从100μg至0.1 ng / ml的梯度向大鼠空肠灌注制备包含高分子量，热不稳定或低分子量，热稳定形式毒素的超滤级分。十二种肠致病菌菌株中的十种产生一种或两种毒素形式，它们以1至10 ng / ml的浓度诱导水分分泌。认为该范围内的值表明该测定系统具有临床上显着的产肠毒素性，并且在本研究中检查的有据可查的产毒菌株的毒素在这些相同浓度下具有活性。来自健康人的十个对照菌株的类似制剂仅以10至100μg/ ml的浓度失活或诱发水分泌。这些观察结果表明， E的肠道致病血清型。从婴儿腹泻流行病中分离出的大肠埃希菌通过产生强效的热不稳定和热稳定的毒素形式而产生腹泻，这种毒素形式改变了水的运输，但在常规测定系统中却没有活性。这些毒素与刺激常规测试系统的毒素在数量或质量上的区别是未知的。

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