To the Editor: Shiga toxin-producing Escherichia coli (STEC) O157:H7 has become a major meat safety issue worldwide. Cattle, an important reservoir of human infection (1), may not be the only source of this organism (2,3). In a survey of pigs in England (4), non-STEC O157 was isolated from four (0.4%) fecal samples collected (after slaughter) from 1,000 pigs. We found that, although an unlikely...

We report the draft genome sequences of three enteropathogenic Escherichia coli (EPEC) isolates that display the O157 serogroup but do not have the Shiga toxin genes (stx), which are characteristic of O157 enterohemorrhagic E. coli (EHEC). E. coli strain RN587/1 has the O157:H8 serotype and possesses the EAF plasmid characteristic of typical EPEC (J. B. Kaper, J. P. Nataro, and H. L. Mobley, Na...

This study was conducted to investigate the effect of free chlorine concentrations in wash water on Escherichia coli O157:H7 reduction, survival, and transference during washing of fresh-cut lettuce. The effectiveness of rewashing for inactivation of E. coli O157:H7 on newly cross-contaminated produce previously washed with solutions containing an insufficient amount of chlorine also was assess...

In a longitudinal study in a Finnish cattle finishing unit we investigated excretion and sources of Escherichia coli O157 in bulls from postweaning until slaughter. Three groups of 31 to 42 calves were sampled in a calf transporter before they entered the farm and four to seven times at approximately monthly intervals at the farm. All calves sampled in the livestock transporter were negative fo...

A multiplex real-time PCR (R-PCR) assay was designed and evaluated on the ABI 7700 sequence detection system (TaqMan) to detect enterohemorrhagic Escherichia coli (EHEC) O157:H7 in pure cultures, feces, and tissues. Three sets of primers and fluorogenic probes were used for amplification and real-time detection of a 106-bp region of the eae gene encoding EHEC O157:H7-specific intimin, and 150-b...

The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield™) or a control (phosphate buffered saline, PBS) was applied to lettuce by either; (1) immersion of lettuce in 500 ml of EcoShield™ 8.3 log PFU/ml or 9.8 log PFU/ml for up to 2 min before inoculation with E. coli O157:H7; (...

Enrichment and direct (nonenrichment) rectoanal mucosal swab (RAMS) culture techniques were developed and compared to traditional fecal culture for the detection of Escherichia coli O157:H7 in experimentally infected and naturally infected cattle. Holstein steers (n = 16) orally dosed with E. coli O157:H7 were sampled after bacterial colonization starting 15 days postinoculation. Enrichment RAM...

INTRODUCTION Strains of Shiga-toxin producing Escherichia coli O157 (STEC O157) are important foodborne pathogens in humans, and outbreaks of illness have been associated with consumption of undercooked beef. Here, we determine the most effective intervention strategies to reduce the prevalence of STEC O157 contaminated beef carcasses using a modelling approach. METHOD A computational model s...

This study was carried out to determine the prevalence of foodborne pathogens, Escherichia coli, E. coli O157:H7, Listeria monocytogenes and Campylobacter spp. on slaughtered cattle in Isfahan, Iran. A total of 203 cattle carcasses were sampled by surface section of neck meat taken immediately after slaughter and analyzed using microbiological examinations. Suspected colonies to E. coli O157:H7...

Escherichia coli O157:H7 (O157) strains are commonly typed by pulsed-field gel electrophoresis (PFGE) following digestion of genomic DNA with the restriction enzyme XbaI. We have shown that O157 strains differ from each other by a series of discrete insertions or deletions, some of which contain recognition sites for XbaI, suggesting that these insertions and deletions are responsible for the d...