Bülte M, Jakob P
Institute of Meat Hygiene and Technology, Free University of Berlin, Germany.
Int J Food Microbiol. 1995 Aug;26(3):335-44. doi: 10.1016/0168-1605(94)00139-w.
Part of the invasion A gene (invA) of slamonellae (Rahn et al., 1992) was amplified and labelled simultaneously with digoxigenin by the polymerase chain reaction (PCR). This was used as gene probe for a colony hybridization assay which included nitrocellulose filter incubation on modified Rambach agar. 312 Salmonella and 268 non-Salmonella strains were hybridized with the invA probe. No false-negative or false-positive results were obtained. In 11 beef samples, which had been contaminated artificially with Salmonella, the test strain was recovered quantitatively with the invA probe. Salmonellae could be detected in 29 samples of 104 further foods of animal origin by means of the gene probe assay in contrast to 27 samples which were positive by the standard method. The invA probe assay allows for the quantitative estimation of Salmonella in fresh meat samples within 48 h. However, with frozen samples a pre-enrichment step is necessary.
利用聚合酶链反应（PCR）对沙门氏菌的侵袭A基因（invA）（Rahn等人，1992年）进行扩增，并同时用地高辛进行标记。将其用作菌落杂交试验的基因探针，该试验包括在改良的兰巴赫琼脂上孵育硝酸纤维素滤膜。用invA探针与312株沙门氏菌和268株非沙门氏菌菌株进行杂交。未获得假阴性或假阳性结果。在11份人工感染沙门氏菌的牛肉样品中，用invA探针定量回收了测试菌株。与标准方法检测出27份阳性样品相比，通过基因探针检测法可在104份其他动物源性食品的29份样品中检测到沙门氏菌。invA探针检测法可在48小时内对鲜肉样品中的沙门氏菌进行定量评估。然而，对于冷冻样品，需要进行预富集步骤。
