Synthetic oligonucleotide primers were used in a polymerase chain reaction (PCR) protocol to target a specific sequence in the gene coding for the A subunit of Escherichia coli verotoxin (VTe-variant, VTev). This PCR protocol permits the VTe-variant target sequence to be distinguished from closely related sequences in the same coding regions for type 1, type 2, and type 2 variant E. coli veroto...

A rapid method for detection of Escherichia coli O157: H7 using multiplex PCR was developed. Two oligonucleotide primer pairs were used for simultaneously detection of vt encoding verotoxin genes for virulence factor and rfbO157 encoding the O-antigen specific for E. coli O157: H7. Multiplex PCR generated two products of 215 bp and 420 bp for vt and rfbO157, respectively. Multiplex PCR detected...

UNLABELLED The presence of highly pathogenic Shiga-toxin-producing Escherichia coli (STEC) in shellfish, upstream waters and sediment from coastal shellfish sites was evaluated using the ISO/TS-13136 method. Shellfish (oysters, mussels and cockles), water and sediment samples were collected monthly over a period of 1 year. The method used real-time PCR detection of stx1, stx2 and eae genes and ...

It is estimated that at least 70% of human illnesses due to non-O157 Shiga toxin-producing Escherichia coli (STEC) in the United States are caused by strains from the top six serogroups (O26, O45, O103, O111, O121, and O145). Procedures for isolating STEC from food products often use plating media that include antimicrobial supplements at concentrations that inhibit background microflora growt...

When 3,972 ground beef enrichments with 6 confirmed to contain a non-O157 Shiga toxin-producing intimin-positive Escherichia coli isolate were tested for Shiga toxin, intimin, and O group (O26, O45, O103, O111, O121, and O145) genes, 183 potential positives and only 2 of the 6 confirmed positives were identified.

Cattle hides are a main source of enterohemorrhagic Escherichia coli (EHEC) contamination of beef carcasses. The objectives of this study were to (1) determine the prevalence of "top 6" non-O157 plus O157:H7 EHEC (EHEC-7) on feedlot cattle hides and their matched preintervention carcasses; (2) assess the agreement among detection methods for these matrices; and (3) conduct a molecular risk asse...

Enterohaemorrhagic Escherichia coli (EHEC) infections in humans are an important public health concern and are commonly acquired via contact with ruminant faeces. Cattle are a key control point however cross-protective vaccines for the control of EHEC in the bovine reservoir do not yet exist. The EHEC serogroups that are predominantly associated with human infection in Europe and North America ...

We used bovine intestinal organ culture to study infection by enterohemorrhagic Escherichia coli serogroups O157, O26, and O111. We show colonization and attaching and effacing lesion formation on explants derived from the ileum, colon, and rectum. Intimin and Tir were detected at the sites of adherent bacteria; Tir was essential for colonization.

Shiga toxin-producing Escherichia coli (STEC) are responsible for human infections, ranging from mild watery diarrhea to hemorrhagic colitis (CH) that may be complicated by hemolytic uremic syndrome (HUS). The main STEC virulence factor is Shiga toxin encoded by the stx gene, located in the genome of a bacteriophage integrated into the bacterial chromosome. The serotype O26:H11 is the second HU...