Featured Research

from universities, journals, and other organizations

Switch that enables Salmonella to sabotage host cells revealed

Date:
April 16, 2010
Source:
Imperial College London
Summary:
A new switch that enables Salmonella bacteria to sabotage host cells is revealed in a new study. Researchers say that the discovery could ultimately lead to drugs that interfere with the switch in order to combat Salmonella and possibly other bacterial infections. In humans, Salmonella causes diseases ranging from gastroenteritis to typhoid fever.

A new switch that enables Salmonella bacteria to sabotage host cells is revealed in a study published in the journal Science.

The researchers behind the study, from Imperial College London, say that the new finding could ultimately lead to drugs that interfere with the switch in order to combat Salmonella and possibly other bacterial infections.

In humans, Salmonella causes diseases ranging from gastroenteritis to typhoid fever. It also causes similar diseases in livestock.

Before the Salmonella cell can replicate inside a much larger human or animal cell and establish an infection, it must first sabotage the cell by injecting it with a cocktail of 'virulence' proteins. These proteins interfere with the cell's defences and help the bacteria to grow.

The new research reveals that a switch needs to be triggered before the bacterial cell can inject its virulence proteins into a host cell.

First, the bacterial cell assembles a needle-like structure on its surface, to deliver the virulence proteins. Then, another set of bacterial proteins pass through the needle and poke a hole in the membrane of the host cell, creating a bridge between the bacterial cell and the host. During this time, the switch inside the bacterial cell acts like a safety catch, holding the virulence proteins back so they are not delivered prematurely.

Once the hole is created, the bacterial cell recognises the pH of the host cell and this switches off the safety catch. This then allows the virulence proteins to be delivered through the hole into the host cell.

The lead author of the study, Professor David Holden from the Department of Medicine at Imperial College London, explained: "The way in which a Salmonella cell delivers its virulence proteins to a host cell is a bit like the way in which a parked aeroplane delivers its passengers to a terminal building. After the plane taxis to its stand at the terminal, a loading bridge is used to connect the plane to the building. Similarly, the bacterial cell waits until it has assembled a special bridge before it delivers its passengers -- the virulence proteins -- to the host cell.

"On a plane there's a safety catch to prevent the doors opening before the bridge is ready, to stop the passengers falling out onto the tarmac. Similarly, the bacterial cell holds back delivery of its proteins using a molecular safety catch, until it senses that the pore has been assembled. Then the safety catch switches off, and virulence proteins can be delivered in an orderly manner. This process is crucial for Salmonella, because if it cannot deliver these proteins properly it cannot establish an infection," added Professor Holden, whose work was supported by grants from the MRC and the Wellcome Trust.

The researchers stress that the research is currently at an early stage but they hope that ultimately, it might be possible to use their findings to design better drugs or vaccines to combat Salmonella-related diseases.


Story Source:

The above story is based on materials provided by Imperial College London. Note: Materials may be edited for content and length.


Journal Reference:

  1. Xiu-Jun Yu, Kieran McGourty, Mei Liu, Kate E. Unsworth, and David W. Holden. pH Sensing by Intracellular Salmonella Induces Effector Translocation. Science, 2010; DOI: 10.1126/science.1189000

Cite This Page:

Imperial College London. "Switch that enables Salmonella to sabotage host cells revealed." ScienceDaily. ScienceDaily, 16 April 2010. <www.sciencedaily.com/releases/2010/04/100415141127.htm>.
Imperial College London. (2010, April 16). Switch that enables Salmonella to sabotage host cells revealed. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2010/04/100415141127.htm
Imperial College London. "Switch that enables Salmonella to sabotage host cells revealed." ScienceDaily. www.sciencedaily.com/releases/2010/04/100415141127.htm (accessed September 1, 2014).

Share This




More Plants & Animals News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins