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 Navigational view of the brain thanks to powerful X-rays
18.10.2017 | Georgia Institute of Technology

nachricht Separating methane and CO2 will become more efficient
18.10.2017 | KU Leuven

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>