Song J H, Cho H, Park M Y, Na D S, Moon H B, Pai C H
Department of Medicine, College of Medicine, University of Ulsan, Seoul, Korea.
J Clin Microbiol. 1993 Jun;31(6):1439-43. doi: 10.1128/jcm.31.6.1439-1443.1993.
A polymerase chain reaction (PCR)-based test was developed for the detection of Salmonella typhi in the blood specimens from patients with typhoid fever. Two pairs of oligonucleotide primers were designed to amplify a 343-bp fragment of the flagellin gene of S. typhi. Amplified products were analyzed by agarose gel electrophoresis and Southern blot hybridization by using a 32P-labeled 40-base probe internal to the amplified DNA. The nested PCR with two pairs of primers could detect 10 organisms of S. typhi as determined by serial dilutions of DNA from S. typhi. The peripheral mononuclear cells from 11 of 12 patients with typhoid fever confirmed by blood culture were positive for DNA fragment of the flagellin gene of S. typhi, whereas 10 blood specimens of patients with other febrile diseases were negative. With the nested PCR, S. typhi DNAs were detected from blood specimens of four patients with suspected typhoid fever on the basis of clinical features but with negative cultures. We suggest that the PCR technique could be used as a novel diagnostic method of typhoid fever, particularly in culture-negative cases.
已开发出一种基于聚合酶链反应（PCR）的检测方法，用于检测伤寒热患者血液样本中的伤寒沙门氏菌。设计了两对寡核苷酸引物，以扩增伤寒沙门氏菌鞭毛蛋白基因的一个343碱基对片段。扩增产物通过琼脂糖凝胶电泳分析，并使用扩增DNA内部的一个32P标记的40碱基探针进行Southern印迹杂交。通过对伤寒沙门氏菌DNA进行系列稀释确定，使用两对引物的巢式PCR能够检测到10个伤寒沙门氏菌菌体。经血培养确诊的12例伤寒热患者中，有11例患者的外周血单核细胞中伤寒沙门氏菌鞭毛蛋白基因的DNA片段呈阳性，而10例其他发热性疾病患者的血液样本呈阴性。通过巢式PCR，从4例根据临床特征怀疑为伤寒热但培养结果为阴性的患者的血液样本中检测到了伤寒沙门氏菌DNA。我们认为，PCR技术可作为伤寒热的一种新型诊断方法，特别是在培养阴性的病例中。
