Bej A K, Steffan R J, DiCesare J, Haff L, Atlas R M
Department of Biology, University of Louisville, Kentucky 40292.
Appl Environ Microbiol. 1990 Feb;56(2):307-14. doi: 10.1128/aem.56.2.307-314.1990.
Polymerase chain reaction (PCR) amplification and gene probe detection of regions of two genes, lacZ and lamB, were tested for their abilities to detect coliform bacteria. Amplification of a segment of the coding region of Escherichia coli lacZ by using a PCR primer annealing temperature of 50 degrees C detected E. coli and other coliform bacteria (including Shigella spp.) but not Salmonella spp. and noncoliform bacteria. Amplification of a region of E. coli lamB by using a primer annealing temperature of 50 degrees C selectively detected E. coli and Salmonella and Shigella spp. PCR amplification and radiolabeled gene probes detected as little as 1 to 10 fg of genomic E. coli DNA and as a few as 1 to 5 viable E. coli cells in 100 ml of water. PCR amplification of lacZ and lamB provides a basis for a method to detect indicators of fecal contamination of water, and amplification of lamB in particular permits detection of E. coli and enteric pathogens (Salmonella and Shigella spp.) with the necessary specificity and sensitivity for monitoring the bacteriological quality of water so as to ensure the safety of water supplies.
对两个基因（lacZ和lamB）区域进行聚合酶链反应（PCR）扩增和基因探针检测，以测试其检测大肠菌群细菌的能力。使用50℃的PCR引物退火温度扩增大肠杆菌lacZ编码区的一段片段，可检测到大肠杆菌和其他大肠菌群细菌（包括志贺氏菌属），但不能检测到沙门氏菌属和非大肠菌群细菌。使用50℃的引物退火温度扩增大肠杆菌lamB的一个区域，可选择性地检测到大肠杆菌、沙门氏菌和志贺氏菌属。PCR扩增和放射性标记基因探针可检测到100毫升水中低至1至10飞克的基因组大肠杆菌DNA以及少至1至5个活的大肠杆菌细胞。lacZ和lamB的PCR扩增为检测水体粪便污染指标的方法提供了基础，特别是lamB的扩增能够以监测水体细菌学质量所需的特异性和灵敏度检测大肠杆菌和肠道病原体（沙门氏菌和志贺氏菌属），从而确保供水安全。
