Stelma G N, Johnson C H, Shah D B
Division of Microbiology, Food and Drug Administration, Cincinnati, Ohio 45226.
J Food Prot. 1985 Mar;48(3):227-231. doi: 10.4315/0362-028X-48.3.227.
A nitrocellulose colony-blot assay was developed to detect enterotoxigenic strains of Clostridium perfringens on an agar medium. To enhance sporulation and enterotoxin production, a number of modifications of the Duncan-Strong (D-S) medium were tested, including the substitution of raffinose for starch and the addition of theobromine, papaverine and various combinations of soil and fecal extracts. Colonies of enterotoxigenic strains were most consistently positive and produced the most intense color reactions on a modified D-S medium containing raffinose, theobromine and 50% (vol/vol) bovine fecal extract. This modified medium stimulated production of detectable enterotoxin by colonies in more than 90% of the enterotoxigenic strains tested. No false-positive reactions were observed. This enzyme-linked, immunosorbent assay (ELISA) was not as effective in the analysis of broth cultures or fecal samples. Our results indicate that the nitrocellulose colony-blot assay will be useful for screening enterotoxigenic strains in epidemiologic studies.
开发了一种硝酸纤维素菌落印迹测定法，用于在琼脂培养基上检测产气荚膜梭菌的产肠毒素菌株。为了增强芽孢形成和肠毒素产生，对邓肯-斯特朗（D-S）培养基进行了多种改良测试，包括用棉子糖替代淀粉以及添加可可碱、罂粟碱和各种土壤与粪便提取物的组合。在含有棉子糖、可可碱和50%（体积/体积）牛粪便提取物的改良D-S培养基上，产肠毒素菌株的菌落最一致呈阳性，且产生的颜色反应最强。这种改良培养基能刺激超过90%受试产肠毒素菌株的菌落产生可检测到的肠毒素。未观察到假阳性反应。这种酶联免疫吸附测定法（ELISA）在肉汤培养物或粪便样本分析中效果不佳。我们的结果表明，硝酸纤维素菌落印迹测定法在流行病学研究中筛选产肠毒素菌株将很有用。
