Miwa N, Nishina T, Kubo S, Atsumi M
Shizuoka Prefectural Western Meat Inspection Center, Japan.
J Vet Med Sci. 1997 Feb;59(2):89-92. doi: 10.1292/jvms.59.89.
The most probable number (MPN) method combined with a nested polymerase chain reaction (nested PCR) for the detection and enumeration of enterotoxigenic Clostridium perfringens in the intestinal contents of cattle, pig and chicken was examined. Ten-fold serial dilutions of samples were added to three tubes of enrichment medium, which were incubated at 37 degrees C for 20-24 hr, and the C. perfringens enterotoxin gene was detected by nested PCR from the enrichment culture without isolating the organism. The results obtained by this method with artificially contaminated intestinal contents were significantly correlated with those obtained by a plate count method. When the method was applied to the detection and enumeration of indigenous enterotoxigenic C. perfringens, the organism was found in two, two and three samples of 10 intestinal contents of cattle, pig and chicken, respectively. Most of the positive samples contained fewer than 10 MPN/g of enterotoxigenic C. perfringens, except one sample of chicken, which contained 1.5 x 10(2) MPN/g. The MPN method combined with nested PCR is easy to perform and may be a useful tool for the detection and enumeration of enterotoxigenic C. perfringens in intestinal contents.
对结合了巢式聚合酶链反应（巢式PCR）的最大可能数（MPN）法进行了检测和计数牛、猪和鸡肠道内容物中产肠毒素性产气荚膜梭菌的研究。将样品进行10倍系列稀释后加入到3管增菌培养基中，于37℃孵育20 - 24小时，然后通过巢式PCR从增菌培养物中检测产气荚膜梭菌肠毒素基因，而无需分离该菌。用该方法对人工污染的肠道内容物检测得到的结果与平板计数法得到的结果显著相关。当该方法应用于检测和计数本地产肠毒素性产气荚膜梭菌时，在牛、猪和鸡的10份肠道内容物样本中，分别有2份、2份和3份样本检测到该菌。除一份鸡肉样本含有1.5×10²MPN/g外，大多数阳性样本中产肠毒素性产气荚膜梭菌的含量低于10 MPN/g。结合巢式PCR的MPN法操作简便，可能是检测和计数肠道内容物产肠毒素性产气荚膜梭菌的有用工具。
