STEC-EPEC Oligonucleotide Microarray: A New Tool for Typing Genetic Variants of the LEE Pathogenicity Island of Human and Animal Shiga Toxin–Producing Escherichia coli (STEC) and Enteropathogenic E. coli (EPEC) Strains

Abstract

Background: Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) are important emerging pathogens that can cause a severe and sometimes fatal illness. Differentiation of eae, tir, espA, espD, and espB gene variants of the locus of enterocyte effacement (LEE) pathogenicity island represents an important tool for typing in routine diagnostics as well as in pathogenesis, epidemiologic, clonal, and immunologic studies. Methods: Type-specific oligonucleotide microarrays and a PCR scheme were designed and constructed for the detection and typing of genetic variants of the LEE genes. Oligonucleotide probes were tested for their specificity against the corresponding type strain by microarray hybridization using fluorescent DNA, either PCR-amplified (single, multiplex, long-range), chromosomal, or amplified chromosomal DNA. Results: The PCR scheme and the oligonucleotide microarray allowed us to distinguish 16 variants (␣1, ␣2, ␤1, ␤2, ␥1, ␥2/, ␦/, ⑀, , , , , , , , ) of the eae gene, 4 variants (␣1, ␤1, ␥1, ␥2/) of the tir gene, 4 variants (␣1, ␤1, ␤2, ␥1) of the espA gene, 3 variants (␣1, ␤1, ␥1) of the espB gene, and 3 variants (␣1, ␤1, ␥1) of the espD gene.

Phylogenetic Backgrounds and Virulence Profiles of Atypical Enteropathogenic Escherichia coli Strains from a Case-Control Study Using Multilocus Sequence Typing and DNA Microarray Analysis

“…In the present study 11 different combinations of these four LEE gene variants were identified. In contrast to previous reports (12,21), several of the espA, espB, tir, and eae variants could be observed in combination with more than just one variant of the other LEE genes. This finding is consistent, as recently suggested, with horizontal exchange between different strains not only of entire LEE sequences but also of smaller gene elements within the LEE (11).…”

Examination of animal and zoonotic pathogens using microarrays

“…These conventional approaches are often time consuming and do not directly characterize virulence markers of the pathogen identified. The virulence gene array of E. coli containing virulence genes was designed for the automated identification and characterization of E. coli and other enteric pathogens in a single test procedure [26,45,56,100].…”

Modeling of pheratic aquifers on E, coli transport influenced by preconsolidation and compressibility of soil

“…The ability to induce A/E lesions is encoded by genes located on a 35-kb pathogen city island called the locus of enterocyte effacement (LEE), which contains the genes encoding intimin, a type III secretion system, secreted proteins (Eps), and the translocated intimin receptor (Tir). Homologues of LEE are also found in STEC and in animal A/E E. coli strains [5,6,11,14,15,16,17,18]. Intimin, a 94-kDa outer-membrane protein encoded by the gene eae, is responsible for the intimate adherence of bacteria to enterocyte membranes [11].…”

“…Homologues of LEE are also found in STEC and in animal A/E E. coli strains [5,6,11,14,15,16,17,18]. Intimin, a 94-kDa outer-membrane protein encoded by the gene eae, is responsible for the intimate adherence of bacteria to enterocyte membranes [11]. The intimin protein is highly variable between different EPEC and STEC serotypes and at least five distinct antigenic variants have been identified [4].…”