Kerdahi K F, Istafanos P F
U.S. Food and Drug Administration, Northeast Regional Laboratory, Brooklyn, NY 11232, USA.
J AOAC Int. 2000 Jan-Feb;83(1):86-8.
A rapid and reliable analytical method was developed to detect and confirm the presence of Listeria monocytogenes in raw and partially processed foods. Forty-nine food samples (25 mixed cut vegetable salad, 12 smoked salmon, and 12 sterile smoked salmon) were individually inoculated with high levels [10-100 colony forming units (cfu)/25 g sample] and low levels (1-10 cfu/25 g sample) of L. monocytogenes, and were screened using the Vitek Immuno Diagnostic Assay (VIDAS) Listeria monocytogenes (VIDAS LMO)]. Positive test results were confirmed as L. monocytogenes by nonradioactive DNA probe. All samples inoculated with high levels of L. monocytogenes were detected by VIDAS and 96% were confirmed as L. monocytogenes by DNA probe. VIDAS LMO detected 89% of samples inoculated with low levels of L. monocytogenes, and 87% of these were confirmed as positive by DNA probe. In addition, 12 other samples (4 from each of mixed cut vegetable salad, smoked salmon, and sterile smoked salmon) were inoculated with high levels of L. ivanovii, L. seeligeri, L. welshimeri, L. innocua, L. grayi, and L. murrayi. Samples were assayed by the same protocol and all gave negative results. Compared with the cultural method, the VIDAS LMO nonradioactive DNA probe combination is highly specific, discriminates between L. monocytogenes and all other Listeria species, and reduces analytical time.
开发了一种快速可靠的分析方法，用于检测和确认生的及部分加工食品中单核细胞增生李斯特菌的存在。四十九个食品样本（25份混合切好的蔬菜沙拉、12份烟熏三文鱼和12份无菌烟熏三文鱼）分别接种高水平[10 - 100菌落形成单位（cfu）/25克样本]和低水平（1 - 10 cfu/25克样本）的单核细胞增生李斯特菌，并使用Vitek免疫诊断分析（VIDAS）单核细胞增生李斯特菌检测试剂盒（VIDAS LMO）进行筛查。通过非放射性DNA探针将阳性检测结果确认为单核细胞增生李斯特菌。所有接种高水平单核细胞增生李斯特菌的样本均被VIDAS检测到，其中96%通过DNA探针确认为单核细胞增生李斯特菌。VIDAS LMO检测到89%接种低水平单核细胞增生李斯特菌的样本，其中87%通过DNA探针确认为阳性。此外，另外12个样本（混合切好的蔬菜沙拉、烟熏三文鱼和无菌烟熏三文鱼各4个）接种了高水平的伊氏李斯特菌、斯氏李斯特菌、威氏李斯特菌、无害李斯特菌、格氏李斯特菌和默氏李斯特菌。样本按照相同方案进行检测，结果均为阴性。与培养方法相比，VIDAS LMO非放射性DNA探针组合具有高度特异性，能够区分单核细胞增生李斯特菌与所有其他李斯特菌属，并缩短了分析时间。
