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

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Fraunhofer Researchers Develop High-Pressure Sensors for Extreme Temperature

28.06.2017 | Power and Electrical Engineering

Zeolite catalysts pave the road to decentral chemical processes Confined space increases reactivity

28.06.2017 | Life Sciences

Extensive Funding for Research on Chromatin, Adrenal Gland, and Cancer Therapy

28.06.2017 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>