Arroyo G, Arroyo J A
Departamento de Microbiologia II, Facultad de Farmacia, Universidad Complutense, Madrid, Spain.
J Appl Bacteriol. 1995 Oct;79(4):360-7. doi: 10.1111/j.1365-2672.1995.tb03149.x.
Rapid detection systems for Salmonella in foodstuffs are currently being developed. However, existing standards still call for application of traditional methods employing pre-enrichment followed by selective enrichment and isolation. The efficacy of various methods was tested using 264 chicken and lamb organ meats. Pre-enrichment was carried out in Tryptone Soy Broth (TSB) and enrichment in Tetrathionate Brilliant Green Broth (TTB) at 37 degrees C, Selenite Broth with Brilliant Green and Sulphapyridine at 37 degrees C and 43 degrees C, and Rappaport-Vassiliadis Broth (RV 10) at 42 degrees C. The isolation media were Brilliant Green Agar (BGA), Deoxycholate Citrate Agar, Hektoen Enteric Agar (HEA) and Salmonella-Shigella Agar. Enrichment in RV/42 degrees C followed by isolation on BGA as recommended by ISO standard no. 6579 and enrichment in TTB/37 degrees C followed by isolation in HEA, no longer recommended by that standard, produced the best results. Low percentages of positive samples and difficulties in detecting Salmonella are the result of interference by competing organisms (Enterobacteriaceae) and the number of salmonellas present after enrichment. A total of 528 samples (TSB, eggs, lamb liver and chicken liver) were inoculated with Salm. enteritidis, Salm. kapemba and Salm. virchow, and the preceding experiment was repeated. All the TSB and egg samples tested positive, but the percentage of positive samples from the lamb and chicken liver was only 81-92%. Recovery of the salmonellas did not depend upon the method employed or the serotype inoculated but instead on interference by competing flora and the numbers of Salmonella present in the samples.
目前正在开发食品中沙门氏菌的快速检测系统。然而，现有标准仍要求采用传统方法，即先进行预富集，然后进行选择性富集和分离。使用264份鸡肉和羊肉内脏进行了各种方法的效能测试。预富集在胰蛋白胨大豆肉汤（TSB）中进行，富集在37℃的四硫磺酸盐煌绿肉汤（TTB）、37℃和43℃的含煌绿和磺胺吡啶的亚硒酸盐肉汤以及42℃的Rappaport-Vassiliadis肉汤（RV 10）中进行。分离培养基为煌绿琼脂（BGA）、脱氧胆酸盐柠檬酸盐琼脂、赫氏肠杆菌琼脂（HEA）和沙门氏菌-志贺氏菌琼脂。按照ISO标准6579的建议，在42℃的RV中富集，然后在BGA上分离，以及在37℃的TTB中富集，然后在HEA中分离（该标准不再推荐此方法），产生了最佳结果。阳性样本比例低以及检测沙门氏菌存在困难是由竞争菌（肠杆菌科）的干扰和富集后沙门氏菌的数量导致的。总共528份样本（TSB、鸡蛋、羊肝和鸡肝）接种了肠炎沙门氏菌、卡彭巴沙门氏菌和魏尔肖沙门氏菌，并重复了之前的实验。所有测试的TSB和鸡蛋样本均呈阳性，但羊肝和鸡肝的阳性样本比例仅为81 - 92%。沙门氏菌的回收率不取决于所采用的方法或接种的血清型，而是取决于竞争菌群的干扰和样本中沙门氏菌的数量。
