Francis K P, Stewart G S
Department of Applied Biochemistry and Food Science, University of Nottingham, Leicestershire, UK.
J Ind Microbiol Biotechnol. 1997 Oct;19(4):286-93. doi: 10.1038/sj.jim.2900463.
The detection of bacteria using PCR is a well-established diagnostic technique. However, conventional PCR requires the use of DNA primer oligomers that are specific to the target organism and, as a consequence, a sample can only be tested for the presence of that specific target. A significant advantage would be to probe a sample for the presence of any bacteria, followed by identification. To achieve this it is necessary to identify a DNA sequence common to all bacteria. Here we demonstrate that such a sequence may be that encoding the major cold-shock proteins. Using two universal PCR primer oligomers from conserved regions of these gene homologues, we have amplified a 200 base-pair DNA sequence from more than 30 diverse Gram-positive and Gram-negative bacteria, including representatives from the genera Aeromonas, Bacillus, Citrobacter, Enterobacter, Enterococcus, Escherichia, Klebsiella, Lactobacillus, Lactococcus, Listeria, Pediococcus, Photobacterium, Proteus, Salmonella, Shigella, Staphylococcus, Streptococcus, and Yersinia. Sequence analysis of the amplified products confirmed a high level of DNA homology. Significantly, however, there are sufficient nucleotide variations to allow the unique allocation of each amplified sequence to its parental bacterium.
使用聚合酶链式反应（PCR）检测细菌是一种成熟的诊断技术。然而，传统的PCR需要使用对目标生物体具有特异性的DNA引物寡聚物，因此，一个样本只能检测该特定目标的存在情况。一个显著的优势是能够检测样本中是否存在任何细菌，然后再进行鉴定。要实现这一点，有必要识别所有细菌共有的DNA序列。在此我们证明，这样的序列可能是编码主要冷休克蛋白的序列。使用来自这些基因同源物保守区域的两种通用PCR引物寡聚物，我们从30多种不同的革兰氏阳性和革兰氏阴性细菌中扩增出了一段200个碱基对的DNA序列，这些细菌包括气单胞菌属、芽孢杆菌属、柠檬酸杆菌属、肠杆菌属、肠球菌属、大肠杆菌属、克雷伯菌属、乳杆菌属、乳球菌属、李斯特菌属、片球菌属、发光杆菌属、变形杆菌属、沙门氏菌属、志贺氏菌属、葡萄球菌属、链球菌属和耶尔森氏菌属的代表菌株。对扩增产物的序列分析证实了高度的DNA同源性。然而，重要的是，存在足够的核苷酸变异，使得每个扩增序列能够唯一地与其亲本细菌相对应。
