Pan Tzu-Ming, Chen Li-Ming, Su Yuan-Chi
Department of Agricultural Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, Taiwan.
J Formos Med Assoc. 2002 Sep;101(9):661-4.
Escherichia coli O157:H7 can cause fatal diseases such as hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura. The early symptoms of E. coli O157:H7 infection are similar to those of infection with other gastrointestinal bacteria, so the availability of a rapid and precise method to identify E. coli O157:H7 is important for early recognition. We report a multiplex polymerase chain reaction (PCR) with primers to detect the presence of the E. coli O157:H7 genes hlyA, which produces enterohemolysin, eaeA (intimin), stx1 (Shiga-like toxin I), stx2 (Shiga-like toxin II), fliC (flagella H-antigen), and rfb (surface O-antigen). The technique improves specificity compared to general PCR when used with > or = 10(3) CFU/assay. Specificity was examined using 32 E. coli O157:H7 strains from the USA, Japan, Canada and Taiwan, all of which were positive for hlyA, eaeA, fliC, rfb, and stx1 and/or stx2. Thirty-five non-O157 enterovirulent E. coli strains, two Shigella sp strains, and two Salmonella sp strains were also examined and none gave the positive gene expression results described above. This multiplex PCR was highly specific in identifying E. coli O157 and was more useful than general PCR in early clinical detection of this pathogen.
大肠杆菌O157:H7可引发诸如溶血尿毒综合征和血栓性血小板减少性紫癜等致命疾病。大肠杆菌O157:H7感染的早期症状与其他胃肠道细菌感染的症状相似，因此，拥有一种快速且精确的方法来鉴定大肠杆菌O157:H7对于早期识别至关重要。我们报道了一种多重聚合酶链反应（PCR），该反应使用引物来检测大肠杆菌O157:H7基因hlyA（产生肠溶血素）、eaeA（紧密素）、stx1（志贺样毒素I）、stx2（志贺样毒素II）、fliC（鞭毛H抗原）和rfb（表面O抗原）的存在。当与≥10³CFU/检测一起使用时，该技术与普通PCR相比提高了特异性。使用来自美国、日本、加拿大和台湾的32株大肠杆菌O157:H7菌株检测特异性，所有这些菌株的hlyA、eaeA、fliC、rfb和stx1和/或stx2均为阳性。还检测了35株非O157肠毒性大肠杆菌菌株、2株志贺氏菌属菌株和2株沙门氏菌属菌株，均未得出上述阳性基因表达结果。这种多重PCR在鉴定大肠杆菌O157方面具有高度特异性，并且在该病原体的早期临床检测中比普通PCR更有用。
