Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Outsmarting the Smartie bug

10.03.2006


Complete description of pneumococcal vaccine targets



New tools in the fight against pneumococci – the bugs targeted by vaccines recently announced by the Department of Health – are described by a team led by scientists from the Wellcome Trust Sanger Institute. They have put together a complete description of the targets of the vaccine that will help monitor the disease and provide new tools for rapid diagnosis.

Pneumococci (formal name Streptococcus pneumoniae) are widespread, causing non-invasive disease, such as ear and sinus infections, and rarer, invasive disease, such as pneumonia and meningitis. About one in three children each year has an ear infection, of which about one-third will be due to the pneumococcus. More significantly, invasive disease is a major cause of death: around 1 million people, mostly young children in developing countries, die each year.


The research, published online today in PLoS Genetics, shows how the target of the vaccines, called the polysaccharide capsule, has evolved and allows the researchers to determine functions of the genes involved. The polysaccharide capsule forms a sugary coat around the bacterium and changing the structure of the capsule can help it to fool our immune defence systems – like a Smartie changing its colour.

“The bug has a polysaccharide coat which can take any one of 90 different forms, known as serotypes,” said Stephen Bentley, leader of the project at the Wellcome Trust Sanger Institute. “The coat is essential for its ability to cause disease and its interaction with our immune system and some serotypes are more likely to be associated with disease.”

“The current vaccines provide excellent protection against pneumococcal disease, but only that caused by some of the 90 serotypes, and it is important that we keep a watch on the development of this organism. Our work in describing all known variants will help in that surveillance”

Two vaccines are available. The first, PCV, recognizes seven forms of the capsule and protects against 82% of infections in children under five years of age in the UK. This will soon be given to UK children under the age of two. A second, PPV, recognizes 23 capsule types and protects against 96% of the UK’s strains but is not effective in infants and is mainly used to protect the elderly.

S. pneumoniae usually lives harmlessly in the air passages and in the first year of life most people are likely to have ‘carried’ at least one strain. It is passed from person to person by sneezing and other aerosols. However, it occasionally passes from the airways to invade other tissues. This can lead to any one of a range of diseases including meningitis and infections of the sinuses, ear, lungs and blood. Why it switches to become invasive is not known.

The team sequenced all genes required to make all 90 forms of the capsule (more than 1,800,000 letters of genetic code), determined their function and studied their evolution. The work gives the most complete understanding of capsule production in any bacterial species.

The new vaccine will protect children from many of the most common serotypes but monitoring is needed to check whether other serotypes start to cause some disease. It is known that pneumococci can switch their capsular polysaccharide and so, if an invasive strain changes its coat to a form not recognised by the vaccine, it might start to become more prevalent and cause disease.

The catalogue of capsules from all known strains will help in the development of new techniques for monitoring changes in capsule type so researchers can look out for such capsule switching.

“The new vaccine that will be given to UK children is very effective at protecting against serious pneumococcal disease, but it does not protect against disease caused by the rarer serotypes,” said Brian Spratt, Professor of Microbiology at Imperial College and a co-author of the study. “The catalogue of capsular genes will help us develop better methods to monitor the effect of the vaccine and allow us to see if changes of capsular types or increased prevalence of the rarer serotypes result in any increase in disease by serotypes not included in the vaccine.

“We must always be vigilant to changes in the properties of microorganisms when we introduce new vaccines or antibiotics. This catalogue will help us to develop new tools to keep a check on the march of the pneumococcus and is also going to give us fascinating insights into the evolution of the amazing diversity of capsular genes that can be produced by this pathogen”

Researchers are at pains to point out that current vaccines are enormously successful and vaccination plays an essential in protecting all of us. The pneumococcal vaccines have been shown to be safe and very effective at preventing widespread infections and are expected to greatly reduce serious pneumococcal disease in UK children, as they already have done in the USA.

Current research, such as the capsule study described here, is intended to ensure we keep ahead of organisms such as S. pneumoniae.

Don Powell | EurekAlert!
Further information:
http://www.plosgenetics.org
http://www.sanger.ac.uk

More articles from Life Sciences:

nachricht World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>