Rhamnolipid (RL) can inhibit biofilm formation of Escherichia coli O157:H7, but the associated mechanism remains unknown. We here conducted comparative physiological and transcriptomic analyses cultures treated with RL untreated to elucidate a potential by which may in E. O157:H7. Anti-biofilm assays showed that over 70% O157:H7 capacity was inhibited treatment 0.25–1 mg/mL RL. Cellular-level a...

A microagglutination (MA) assay to identify antibodies to Escherichia coli O111 and O157 was conducted in sera collected from 60 patients during a food-poisoning outbreak affecting 181 patients in Japan which was caused by the consumption of contaminated raw beef. Enterohemorrhagic E. coli (EHEC) O111:H8 and/or O157:H7 was isolated from the stools of some of the patients, but the total rate of ...

The purpose of this study was to investigate the effect of different levels of Pseudomonas fluorescens (10(2) and 10(6) log10 cfu/ml) and Lactobacillus plantarum (10(2) and 10(4) log10 cfu/ml) on the growth of Escherichia coli O157:H7 on beef loins. Beef loins inoculated with E. coli O157:H7 and P. fluorescens were aerobically stored for 7 days at 4 ºC, while those inoculated with E. coli O157:...

Escherichia coli O157:H7 is a foodborne pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. Positive identification of E. coli O157:H7 is made using biochemical tests and specific antisera or latex agglutination reagents for the O157 and H7 antigens. However, under certain conditions, some E. coli O157:H7 isolates can appear to be nonreactive with H7 antisera and may require...

Shiga-toxigenic Escherichia coli strains belonging to serotype O157 are important human pathogens, but the genetic basis of expression of the O157 antigen and the role played by the lipopolysaccharide O side chain in the adherence of this organism to epithelial cells are not understood. We performed TnphoA mutagenesis on E. coli O157:H7 strain 86-24 to identify a mutant (strain F12) deficient i...

Shiga toxin-producing Escherichia coli O157:H7 (STEC) is by far the most prevalent serotype associated with hemolytic uremic syndrome (HUS) although many non-O157 STEC strains have been also isolated from patients with HUS. The main virulence factor of STEC is the Shiga toxin type 2 (Stx2) present in O157 and non-O157 strains. Recently, another toxin, named subtilase cytotoxin (SubAB), has been...

Thermal tolerance of pathogenic bacteria has been shown to increase after exposure to sublethal elevated temperatures, or heat shock. We evaluated the effect of heat shock at 48°C on thermal tolerance (D55°C) of cocktails of O157 and non-O157 Shiga toxigenic Escherichia coli (STEC) and Salmonella in lean ground beef with or without moisture-enhancing ingredients. Beef was moisture enhanced to 1...

Verotoxinogenic E. coli O157:H7 (VTEC O157:H7) can cause severe disease in humans, with bloody diarrhea and complications such as haemolytic uraemic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP) and even death. Animals carry VTEC O157:H7 asymptomatically. Ruminants, especially cattle, are considered to be the main reservoir, although the bacterium can occasionally be isolated from o...

Polymorphic amplified typing sequences (PATS) for Escherichia coli O157:H7 (O157) was previously based on indels containing XbaI restriction enzyme sites occurring in O-island sequences of the O157 genome. This strain-typing system, referred to as XbaI-based PATS, typed every O157 isolate tested in a reproducible, rapid, straightforward, and easy-to-interpret manner and had technical advantages...

In preparing sheep for an in vivo Escherichia coli O157:H7 eradication trial, we found that 20/39 members of a single flock were naturally colonized by O157:H7-infecting phages. Characterization showed these were all one phage type (subsequently named CEV2) infecting 15/16 O157:H7, 7/72 ECOR and common lab strains. Further characterization by PFGE (genome∼120 kb), restriction enzyme digest (DNA...