Detection of Various Variant Verotoxin Genes in Escherichia coli by Polymerase Chain Reaction

Abstract

We constructed common primers for the polymerase chain reaction to detect the genes for various Verotoxins reported, that is, VT1 (or SLT-I), VT2 (or SLT-II), VT2vha, VT2vhb, SLTIIv (or VT2vpl, VTe) and SLT-IIva (or VT2vp2). A total of 80 Verocytotoxin-producing Escherichia coli strains isolated from humans, domestic animals and meats gave a positive result by PCR with the designed common primers. Digestion by restriction endonucleases BglII and EcoT14I of the amplicon of the VT2vp2 gene gave specific bands of the expected sizes, but not of the amplicons of other VT genes, suggesting a possible method for identification of the VT2vp2 gene. Application of the PCR with the designed primers in diagnostic and epidemiological studies on VTEC infection is also discussed.

Genotypic variations of Shiga toxin-converting phages from enterohaemorrhagic Escherichia coli O157: H7 isolates

“…The phages, their host strains and the stx pro®les obtained by three different PCR analysis are summarised in Table 1. All phages produced a 900-bp PCR-ampli®ed product common to both stx 1 and stx 2 by primers described by Lin et al [18]. The PCR analysis of Cebula et al [14], which differentiates stx 1 from stx 2 , showed that 14 of the phages had stx 1 and that 37 phages had stx 2 genes.…”

“…All isolates were found to have stx genes by PCR assays carried out according to Lin et al [18]. 566 R. OSAWA ET AL.…”

“…The presence of the stx gene in the host strains and in the isolated phages was con®rmed by a PCR assay as described by Lin et al [18], with common primers to detect genes for Stx1 (or VT1 [19]), Stx2 (or VT2 [5]), VT2vha [20], VT2vhb [20], VT2vpl [18] (or SLT-IIv [21]) and VT2vp2 [18] (or SLT-IIva [22]). Subsequently, more speci®c sets of primers were designed to differentiate the stx 1 gene from the stx 2 gene as described by Cebula et al [14].…”

Vero Toxins (Shiga‐Like Toxins) Produced by Enterohemorrhagic Escherichia coli (Verocytotoxin‐Producing E. coli)

“…(or VT2v-b) (32,73,93) SLT-IIva (VT2vp2) (22,50), SLTIIc (85), and others (51,57,74) have been reported. The nucleotide sequence of the VT1 gene and the amino acid sequence of VT1 are essentially identical to those of Shiga toxin.…”

Evaluation of Five Polymerase Chain Reaction (PCR) Assays for Diagnosis of the Shiga Toxin 2f-Producing <i>Escherichia coli</i>

“…These strains were previously isolated from domestic pigeons from 4 provinces in Iran (11). For the LOD comparison of the PCR protocols tested, we selected 6 strains of different genotypes, which were previously genotyped using the enerobacterial repetitive intergenic consensus sequences (ERIC) PCR (11).…”