Nunez-Montiel O L, Thompson F S, Dowell V R
J Clin Microbiol. 1983 Feb;17(2):382-5. doi: 10.1128/jcm.17.2.382-385.1983.
A new medium, norleucine-tyrosine (NT) broth, was developed for rapid identification of Clostridium difficile on the basis of caproic acid and p-cresol production. The NT broth consists of 0.5% Trypticase (BBL Microbiology Systems, Cockeysville, Md.), 0.5% yeast extract (Difco Laboratories, Detroit), 0.2% L-norleucine and 0.2% L-tyrosine (wt/vol; final concentrations), and a mixture of salts. The procedure for demonstrating caproic acid and p-cresol production involves extracting NT broth cultures with ether or chloroform and analyzing the extracts with a gas-liquid chromatograph equipped with a thermal conductivity detector, as is customary for analysis of volatile fatty acids. A total of 120 strains of C. difficile from diverse geographic locations were tested by this procedure, and they all produced caproic acid and p-cresol in NT broth. No other Clostridium species or other microorganisms tested have been found to produce both products in NT broth.
一种新的培养基——正亮氨酸 - 酪氨酸（NT）肉汤，基于己酸和对甲酚的产生，被开发用于快速鉴定艰难梭菌。NT肉汤由0.5%胰蛋白酶（BBL微生物系统公司，马里兰州科基斯维尔）、0.5%酵母提取物（迪福公司实验室，底特律）、0.2% L - 正亮氨酸和0.2% L - 酪氨酸（重量/体积；终浓度）以及一种盐混合物组成。证明己酸和对甲酚产生的程序包括用乙醚或氯仿萃取NT肉汤培养物，并使用配备热导检测器的气液色谱仪分析提取物，这是分析挥发性脂肪酸的常规方法。通过该程序对来自不同地理位置的总共120株艰难梭菌菌株进行了测试，它们在NT肉汤中都产生了己酸和对甲酚。未发现其他梭菌属物种或测试的其他微生物在NT肉汤中同时产生这两种产物。
