Study helps explain how pathogenic E. coli bacterium causes illness

Mar 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.

Explore further: Breakthrough in understanding of important blood protein

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

Provided by National Institutes of Health

1 /5 (1 vote)
add to favorites email to friend print save as pdf

Related Stories

New Vaccines May Help Thwart E. coli O157:H7

Dec 18, 2009

(PhysOrg.com) -- Immunizing calves with either of two forms of a vaccine newly developed by Agricultural Research Service (ARS) scientists might reduce the spread of sometimes deadly Escherichia coli O157:H7 ...

Disease-causing Escherichia coli: 'I will survive'

Sep 09, 2009

Strains of Escherichia coli bacteria that cause food poisoning have been shown to have marked differences in the numbers of genes they carry compared to laboratory strains of E. coli. Some of these genes may enable them t ...

Researchers Uncover a Secret of the Black Death

Sep 18, 2006

Yersinia pestis, the bacteria that causes plague, is a sneaky little intruder with a remarkable ability to evade the body’s immune system. Upon entering an organism, Y. pestis employs a variety of strategies to slip below ...

Recommended for you

Breakthrough in understanding of important blood protein

17 hours ago

The human body contains a unique protein that has the unusual property of destroying itself after a few hours of existence - it must therefore be continually recreated and is no stable protein. The protein, ...

User comments : 0