Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Secrets Of Successful Pathogen Revealed

24.08.2005


Two groups of scientists have uncovered key secrets of success of a major pathogen responsible for recent food poisoning outbreaks. The ability of Salmonella bacteria to act quickly, both on an evolutionary timescale and during the early minutes of infection, has been investigated in detail for the first time.



This month more than 1,700 cases of Salmonella food poisoning from chicken were reported in Spain and earlier outbreaks in Europe have been linked to lettuce and eggs.

“For bacteria to do well, they have to react very fast, and we have shown Salmonella to be remarkably dynamic”, says Professor Jay Hinton of the UK’s Institute of Food Research (IFR).


In a study published tomorrow by IFR and Sweden’s Uppsala University, scientists found that Salmonella can evolve at a surprisingly rapid rate by jettisoning superfluous DNA.

One hundred million years ago Salmonella evolved from E. coli bacteria that lived freely in the environment. Salmonella developed the ability to parasitize animals by losing many genes and gaining new ones from other bacteria.

Using DNA microarrays to analyse the results of “experimental evolution”, the scientists tracked Salmonella in real time over 6,750 generations to make the first estimation of the rate of gene loss for any bacterium.

Project leader Professor Dan Andersson says: “Nearly one quarter of the bacteria’s genes could be lost in only 50,000 years. This was a surprise to us as it had been thought this process would take many millions of years”.

In separate research, Professor Hinton of IFR and Professor John Ladbury of UCL (University College London) investigated the response of Salmonella to body temperature. This had not been studied before.

“Bacteria are efficient organisms”, says Professor Hinton. “We found that at low temperatures Salmonella switches off genes required for infection and switches them on once inside a warm animal body. It does not want to expend energy needlessly when waiting to be eaten on a lettuce leaf”.

The team discovered the thermal switch, a protein called H-NS, and found that it allows 532 genes to be activated within minutes. These genes code for functions essential for infection such as the ability to swim and to infect gut cells.

Professor Ladbury believes that as the temperature rises, the protein structure which compacts Salmonella DNA changes shape, allowing gene expression to start.

“These findings help to explain the success of this pathogen in infecting so many different species of animals and reptiles, as well as man”, says Professor Hinton.

Salmonella kills about 1 million people worldwide every year, and now kills more people in the West than any other foodborne pathogen.

Zoe Dunford | alfa
Further information:
http://www.ifr.ac.uk

More articles from Health and Medicine:

nachricht Study tracks inner workings of the brain with new biosensor
16.08.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>