Germani Y, Guesdon J L, Phalente L, Begaud E, Moreau J P
Unité de Bactériologie Expérimentale, Institut Pasteur, Nouméa, New Caledonia.
J Clin Microbiol. 1988 May;26(5):995-9. doi: 10.1128/jcm.26.5.995-999.1988.
Two erythrocyte immunoassay techniques to detect the presence of Escherichia coli heat-labile enterotoxin (LTh) in stool supernatants and cell-free culture supernatants were compared. In the competitive assay, GM1 ganglioside was coated onto V-shaped-well microdilution plates and enterotoxin was coupled to sheep erythrocytes. As little as 0.8 ng of LTh per ml was detected by this method, which was based on the competition between the LTh of the test sample and the sensitized erythrocytes. The second assay made use of chimera antibody prepared by coupling polyclonal anti-LTh antibody to a monoclonal antibody specific for sheep erythrocytes. In this case, LTh, which was specifically bound to a GM1 ganglioside-coated plate, was detected by successively adding the chimera antibody and sheep erythrocytes. The limit of detection of the chimera antibody erythrocyte immunoassay was 0.2 ng/ml. Stool samples were collected from 167 infants hospitalized for diarrhea in the hospital of Noumea, New Caledonia. False-negative reactions due to proteases present in the stool samples were avoided by the addition of phenylmethylsulfonyl fluoride.
比较了两种红细胞免疫测定技术，用于检测粪便上清液和无细胞培养上清液中大肠杆菌热不稳定肠毒素（LTh）的存在。在竞争性测定中，将GM1神经节苷脂包被在V形孔微量稀释板上，并将肠毒素与绵羊红细胞偶联。该方法基于测试样品的LTh与致敏红细胞之间的竞争，每毫升可检测到低至0.8纳克的LTh。第二种测定方法使用通过将多克隆抗LTh抗体与针对绵羊红细胞的单克隆抗体偶联而制备的嵌合抗体。在这种情况下，通过依次添加嵌合抗体和绵羊红细胞来检测与GM1神经节苷脂包被板特异性结合的LTh。嵌合抗体红细胞免疫测定的检测限为0.2纳克/毫升。从新喀里多尼亚努美阿医院因腹泻住院的167名婴儿中收集粪便样本。通过添加苯甲基磺酰氟避免了粪便样本中存在的蛋白酶引起的假阴性反应。
