The toxins are manufactured by communities of the hospital superbug Pseudomonas aeruginosa called biofilms, which are up to a thousand times more resistant to antibiotics than free-floating single bacterial cells.
"This is the first time that anyone has successfully proved that the way the bacteria grow - either as a biofilm, or living as individuals - affects the type of proteins they can secrete, and therefore how dangerous they can potentially be to our health," says Dr Martin Welch from the University of Cambridge, UK.
"Acute diseases caused by bacteria can advance at an astonishing rate and tests have associated these types of disease with free-floating bacteria. Such free-floating bugs often secrete tissue-damaging poisons and enzymes to break down our cells, contributing to the way the disease develops, so it is natural to blame them. By contrast, chronic or long-term infections seem to be associated with biofilms, which were thought to be much less aggressive," says Dr Welch.
The research team's findings are very important to the NHS, which spends millions of pounds every year fighting chronic long-term bacterial infections which are incredibly difficult to treat.
"For example, these chronic infections by bacteria are now the major cause of death and serious disability in cystic fibrosis patients - which is the most common lethal inherited disease in the UK and affects about 8,000 people," says Dr Welch.
In cystic fibrosis the gene defect means that people are very susceptible to a particular group of opportunistic bacteria including Pseudomonas aeruginosa, which is one of the three major hospital superbugs. Aggressive antibiotic treatment can usually control the infection in cystic fibrosis sufferers but eventually the strain becomes completely resistant to antibiotics, leading to respiratory failure and death, often while still in their thirties.
"We think that the bacteria in a cystic fibrosis sufferer's lungs are partly living in communities called biofilms, and although medical scientists have investigated their strongly antibiotic-resistant properties, very little research has been done to investigate any active contribution the biofilms might have in causing diseases in the first place," says Dr Welch.
A widely-held view is that biofilms serve as reservoirs of bacteria that do relatively little harm; they just sit there. The main danger is thought to be from 'blooms' of free living cells which occasionally break away from the biofilm and cause periods of poor lung function in the cystic fibrosis patients. "In this scenario, it follows that bacteria in a biofilm will produce fewer disease-causing chemicals than free-living cells of the same type of bacteria, which is a prediction that we can test," says Dr Welch.
"We found that, in contrast to expectation, biofilms do indeed produce harmful chemicals. However, the type of tissue-degrading enzymes and toxins made by the biofilm bacteria differ from those produced by free-floating bugs, which may help them to survive attacks by our immune systems."
In addition, the scientists discovered that the biofilm bacteria can produce a protein which their analysis suggests is similar to one of the active ingredients in rattlesnake venom. In the case of rattlesnake venom the protein causes the host cells to commit suicide and die, which is one reason why rattlesnake bites are so dangerous. The research team is currently studying the protein to see if it functions in the same way.
In addition the scientists have found evidence that the trigger for the bacteria to start producing these extra virulence factors is turned on very shortly after the biofilm begins to form. Once the scientists have fully identified the virulence factors created by the biofilm bacteria, the proteins and enzymes may be targeted to develop drugs for a variety of uses, including the treatment of hospital superbugs, cancer and cystic fibrosis.
Lucy Goodchild | alfa
Zeolite catalysts pave the road to decentral chemical processes Confined space increases reactivity
28.06.2017 | Technische Universität München
For a chimpanzee, one good turn deserves another
27.06.2017 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)
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...
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...
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...
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...
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)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
28.06.2017 | Awards Funding
28.06.2017 | Earth Sciences
28.06.2017 | Physics and Astronomy