E.coli O157 & Haemolytic Uraemic Syndrome

A novel antimicrobial peptide significantly enhances acid-induced killing of Shiga toxin-producing E.coli strains

19th July 2011

A new study published in July's edition of Microbiology focuses on a novel peptide - a protein too small to merit the title. Known as wrwycr, it has proven to disrupt E. coli bacteria's natural ability to repair its DNA after damage from stomach acid.

Early lab tests show that after contact with this peptide, Shiga toxin-producing strains of E.coli die off in stomach acid faster than is necessary to enter human intestines, where they cause the medical complications associated with the toxin. Non-Shiga toxin producing E.coli suffer similar fates, but pose little concern in comparison.

Though the team is far from achieving its ultimate goals, the big idea is to use this peptide in a spray or wash for fruits and vegetables, essentially weakening potential pathogens before anyone even chomps into the produce. So far, they've only completed the initial tests to prove the theory might work.

"We exposed pathogenic E. coli to this peptide for five minutes at room temperature -- and of course compared them to bacteria that had not seen the peptide. The results were profound," said Debora Foster, Ph.D., cellular biology professor at Ryerson University and the study's lead author. "We were seeing dramatic differences in the survival rates after acid treatment."

Along with Dr Anca Segall from San Diego State University and Dr Steve Goodman from the University of Southern California, Foster's team tested the survivability of several E.coli strains - including the well-known O157:H7 - in acid with and without the peptide.

Without it, large, viable numbers of bacteria still survived in the acid after many hours -- long enough to move on to colonize the intestines. A meal will typically pass through the stomach over 4 to 5 hours. But after exposing O157:H7 bacteria to the peptide, the team couldn't detect any E.coli after as little as 30 minutes in the acid.

The survival rates of other strains varied, but each dropped significantly when exposed to the peptide. The team members have not been able to test E.coli O104:H4, the strain behind the European outbreak, but they hope to receive a sample soon.

1 of 46
Next > Last >>

1st February 2024

A recent news article in the Environmental Health News indicates the concerns the Chartered Institute of Environmental Health (CIEH) have over UK food safety being at risk, due to lack of staff. Food safety allocated posts supporte... on
2nd January 2024

On the 29th December 2023 the FSA stated on their website “Chiltern Artisan recalls Chilli Sticks because of contamination with E. Coli. Chiltern Artisan has taken the precautionary step of recalling Chiltern Artisan Chilli Sticks because E. Coli has been fo... on
28th December 2023

Amy Douglas, Incident Director for Gastrointestinal Infections and Food Safety Division at UKHSA, said: "There have been at least 30 confirmed cases of this specific outbreak strain of STEC in the UK." - Link below. ... on
25th December 2023

The recall for Route des Terroirs is recalling Morbier Maison Monts & Terroirs Chalet De Vevy Raw Cows’ Milk Cheese because Shiga toxin-producing E.coli has been found in some batches of this product. This recall was announced today 25/12/2023. ... on
6th December 2023

Information Rights Team ... on
1 of 46
Next > Last >>

Designed by Robert Woods. View our Cookie & Privacy Policy