Study helps explain how pathogenic E. coli bacterium causes illness

March 14, 2011

Scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have shown how the O157:H7 strain of Escherichia coli causes infection and thrives by manipulating the host immune response. The bacterium secretes a protein called NleH1 that directs the host immune enzyme IKK-beta to alter specific immune responses. This process not only helps the bacterium evade elimination by the immune system, it also works to prolong the survival of the infected host, enabling the bacterium to persist and ultimately spread to unaffected individuals. This finely balanced mechanism, observed in both laboratory and animal models, could be relevant to other pathogens involved in foodborne diseases.

While most E. coli strains help check the growth of harmful bacteria in the guts of animals and humans, a few E. coli strains, such as O157:H7, can cause severe diarrhea, abdominal cramps and, in rare cases, death. Human cases of E. coli O157:H7 have been linked to consumption of raw, undercooked, or spoiled meat.

NIAID researchers plan to use the new information to further study how the host mounts a response to E. coli O157:H7 when infection begins and how the selectively blocks these defenses. Several foodborne pathogens, including Shigella and Salmonella, use a similar secretion system to disrupt host immune responses and infect gut cells.

More information: F Wan, et al. IKK-beta phosphorylation regulates RPS3 nuclear translocation and NF-kappa B function during infection with Escherichia coli strain O157:H7. Nature Immunology. DOI:10.1038/ni.2007

Related Stories

Recommended for you

Tracking effects of a food preservative on the gut microbiome

December 18, 2017
Antimicrobial compounds added to preserve food during storage are believed to be benign and non-toxic to the consumer, but there is "a critical scientific gap in understanding the potential interactions" they may have with ...

Drug found that induces apoptosis in myofibroblasts reducing fibrosis in scleroderma

December 15, 2017
(Medical Xpress)—An international team of researchers has found that the drug navitoclax can induce apoptosis (self-destruction) in myofibroblasts in mice, reducing the spread of fibrosis in scleroderma. In their paper ...

How defeating THOR could bring a hammer down on cancer

December 14, 2017
It turns out Thor, the Norse god of thunder and the Marvel superhero, has special powers when it comes to cancer too.

Researchers track muscle stem cell dynamics in response to injury and aging

December 14, 2017
A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) describes the biology behind why muscle stem cells respond differently to aging or injury. The findings, published in Cell Stem Cell, ...

'Human chronobiome' study informs timing of drug delivery, precision medicine approaches

December 13, 2017
Symptoms and efficacy of medications—and indeed, many aspects of the human body itself—vary by time of day. Physicians tell patients to take their statins at bedtime because the related liver enzymes are more active during ...

Study confirms link between the number of older brothers and increased odds of being homosexual

December 12, 2017
Groundbreaking research led by a team from Brock University has further confirmed that sexual orientation for men is likely determined in the womb.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.