Rappelli P, Maddau G, Mannu F, Colombo M M, Fiori P L, Cappuccinelli P
Department of Biomedical Sciences, University of Sassari, Italy.
New Microbiol. 2001 Jan;24(1):77-83.
Diarrheagenic E. coli comprise a diverse group of microorganisms responsible for gastrointestinal diseases in humans. On the basis of their virulence traits they are distinguished from the non-pathogenic E. coli and classified in several categories. Molecular methods represent the most reliable techniques for distinguishing pathogenic from non-pathogenic E. coli and characterising their pathogenic features. In this paper we report the development of a set of three multiplex PCR assays for the simultaneous and rapid identification of diarrheagenic E. coli belonging to ETEC, EPEC, EHEC and EIEC groups. Assay 1 utilizes primer pairs specific for genes coding for ST and LT toxins of ETEC, and for the E. coli beta-glucuronidase (uidA); assay 2 detects the presence of the eae and bfpA genes of EPEC, and assay 3 recognizes stx1 and stx2 of EHEC, and ial of EIEC. This technique has been validated on 190 E. coli isolated in Angola, Italy and Mozambique from feces of children with diarrhea. Results obtained with the set of multiplex PCR demonstrated 100% accordance with those obtained for the same isolates by PCR on single target genes. The proposed set of multiplex PCRs is the first reported assay that allows the simultaneous characterization of the four categories of diarrheagenic E. coli.
致泻性大肠杆菌是一类多样的微生物，可导致人类胃肠道疾病。根据其毒力特性，它们与非致病性大肠杆菌相区分，并分为几类。分子方法是区分致病性大肠杆菌与非致病性大肠杆菌并表征其致病特征的最可靠技术。在本文中，我们报告了一组三种多重PCR检测方法的开发，用于同时快速鉴定属于肠毒素型大肠杆菌（ETEC）、肠致病性大肠杆菌（EPEC）、肠出血性大肠杆菌（EHEC）和肠侵袭性大肠杆菌（EIEC）组的致泻性大肠杆菌。检测方法1利用针对编码ETEC的ST和LT毒素以及大肠杆菌β-葡萄糖醛酸酶（uidA）的基因的引物对；检测方法2检测EPEC的eae和bfpA基因的存在，检测方法3识别EHEC的stx1和stx2以及EIEC的ial。该技术已在安哥拉、意大利和莫桑比克从腹泻儿童粪便中分离出的190株大肠杆菌上得到验证。多重PCR检测组获得的结果与通过对单个靶基因进行PCR对相同分离株获得的结果显示100%一致。所提出的多重PCR检测组是首次报道的能够同时表征四类致泻性大肠杆菌的检测方法。
