Scientists discover multiple gene switches in Salmonella, offer new ways to curb infection

Apr 23, 2012

Scientists have discovered multiple gene switches in Salmonella that offer new ways to curb human infection. The discovery of the mechanisms of gene regulation could lead to the development of antibiotics to reduce the levels of disease caused by Salmonella. The breakthrough was made by Professor Jay Hinton, Stokes Professor of Microbial Pathogenesis, Trinity College Dublin and his research team* and has just been published in the leading journal Proceedings of the National Academy of Sciences (PNAS). Science Foundation Ireland funded the research.

Salmonella causes food poisoning and kills around 400,000 people worldwide every year. The bacteria are particularly effective at causing human infection because they can survive a series of harsh conditions that kill most bacteria including strong acids in the stomach and the anaerobic and salty environment of the intestine.

"It's a decade since we discovered the Salmonella genes active during infection of ," said Professor Hinton. "Now we have found the switches that control these critical genes. My team has gained an unprecedented view of the way that Salmonella modulates the level of the weapon systems that cause human disease."

Salmonella bacteria use a variety of proteins that act as weapons to hijack and attack . Despite many decades of research throughout the world, little was understood about the way that Salmonella genes that control this weapon system are switched on. Now Professor Hinton's team has used a new approach to identify the switches of the genes. The exciting new findings show that Salmonella bacteria have more than 1,800 switches, called 'promoters' and reveals how they work.

Understanding how Salmonella switches on its genes should aid the discovery of that will knock out the weapon systems of Salmonella and stop the bacteria causing infection.

The researchers also identified 60 new , called 'small RNAs'. Some of these can actually override the switches of Salmonella genes.

"Just five years ago, we didn't realise that small RNAs played such an important role – or that the switches of so many Salmonella genes were controlled by small RNAs. Identifying these small RNAs could lead to completely new ways to prevent bacterial disease, but this will take at least a decade, " said Professor Hinton.

Professor Hinton's team worked in collaboration with the Wellcome Trust Sanger Institute and the University of Würzburg, and used several cutting edge techniques during the project, called chip-chip and RNA-seq. "I think one reason that our findings are making such impact is that this combination of the new technologies has not been used before for a bacterial pathogen" says lead author Dr Carsten Kröger.

Explore further: Molecular gate that could keep cancer cells locked up

More information: "The transcriptional landscape and small RNAs of Salmonella enterica serovar Typhimurium" Proceedings of the National Academy of Sciences (2012).

Related Stories

How bugs avoid getting sick after sex

Aug 18, 2006

Scientists at the Institute of Food Research in Norwich revealed today how the promiscuous Salmonella bacterium protects itself from getting ill after acquiring foreign DNA through "sex" with other bacteria. ...

Salmonella in garden birds responsive to antibiotics

Jun 02, 2008

Scientists at the University of Liverpool have found that Salmonella bacteria found in garden birds are sensitive to antibiotics, suggesting that the infection is unlike the bacteria found in livestock and humans.

Discovery paves way for salmonella vaccine

Feb 13, 2012

(Medical Xpress) -- An international research team led by a University of California, Davis, immunologist has taken an important step toward an effective vaccine against salmonella, a group of increasingly antibiotic-resistant ...

Snakes poisoned at birth

Feb 23, 2006

Scientists in Germany have found that a significant route of transmission of Salmonella in non egg-laying snakes is from the mother to the offspring during pregnancy and birth.

Salmonella survives better in stomach due to altered DNA

Jan 29, 2007

Since 1995 there has been a considerable increase in the number of infections with a specific type of Salmonella bacteria transmitted via food. This type, Salmonella serovar Typhimurium DT104, is resistant to at least five ...

Recommended for you

Molecular gate that could keep cancer cells locked up

Jul 31, 2014

In a study published today in Genes & Development, Dr Christian Speck from the MRC Clinical Sciences Centre's DNA Replication group, in collaboration with Brookhaven National Laboratory (BNL), New York, ...

The 'memory' of starvation is in your genes

Jul 31, 2014

During the winter of 1944, the Nazis blocked food supplies to the western Netherlands, creating a period of widespread famine and devastation. The impact of starvation on expectant mothers produced one of the first known ...

Sugar mimics guide stem cells toward neural fate

Jul 30, 2014

Embryonic stem cells can develop into a multitude of cells types. Researchers would like to understand how to channel that development into the specific types of mature cells that make up the organs and other structures of ...

User comments : 0