Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genome of Clostridium botulinum reveals the background to world’s deadliest toxin

29.05.2007
The genome of the organism that produces the world’s most lethal toxin is revealed today. This toxin is the one real weapon in the genome of Clostridium botulinum and less than 2 kg — the weight of two bags of sugar — is enough to kill every person on the planet. Very small amounts of the same toxin are used in medical treatments, one of which is known as Botox.

The genome sequence shows that C. botulinum doesn’t have subtle tools to evade our human defences or tricky methods of acquiring resistance to antibiotics. It lives either as a dormant spore or as a scavenger of decaying animal materials in the soil, and doesn’t interact with human or other large animal hosts for prolonged periods of time.

Occasionally it gets into a living animal, via contaminated food or open wounds, leading to infant botulism or wound botulism, both of which are serious human infections. The host can be quickly overpowered and, in some cases, killed by the toxin, and C. botulinum has a new food source.

“Although in the same group as Clostridium difficile — the Cdiff superbug — C. botulinum has a genome that is remarkable because it is so stable,“ commented Dr Mohammed Sebaihia, lead author on the paper from the Wellcome Trust Sanger Institute. “Unlike Cdiff, in which more than 10 per cent of genes have been acquired from other bacteria, there is almost no footprint of these in C. botulinum.”

... more about:
»Botulinum »Clostridium »Soil »Toxin »clostridia

There are several types of C. botulinum: although described as variants of a single species, they are really very different organisms linked simply because they have the deadly toxin. For each type, there is also a near-identical but harmless relative that lacks the toxin. C. sporogenes is the non-malignant, near twin of the organism sequenced.

Professor Mike Peck, from the Institute of Food Research, commented that “It is astonishing that 43 per cent of the predicted genes in the C. botulinum genome are absent from the other five sequenced clostridia, and only 16 per cent of the C. botulinum genes are common to all five. Our findings emphasise just how different clostridia are from each other.”

C. botulinum toxin stops nerves from working — the basis of its use in medicine to control tremors and in cosmetic treatments. For the prey of its opportunistic attacks, death is swift. Perhaps the most important tool it has to act out its stealth attacks is its ability to hibernate when times are hard by forming dormant spores.

More than 110 of its set of almost 3700 genes are used to control spore formation and germination when opportunity arises.

“C. botulinum shows us one extreme of the ways that bacteria can make the most of animal hosts,” explained Dr Julian Parkhill of the Wellcome Trust Sanger Institute. “Some organisms use subtle approaches, elegantly choreographing their interaction with us and our defences.

“C. botulinum takes the opposite approach. It lies in wait and, if it gets the opportunity, it hits its host with a microbial sledgehammer. It then eats the remains and lays low until the next host comes along.”

The genome sequence is peppered with genes that produce enzymes to digest proteins and other animal material in the soil. Also found, uniquely in this species, is a range of genes that allow it to attack the many insect and other small creatures that live in the soil. The ‘chitinases’ produced by these genes can degrade the casing of insects and small crustaceans.

It is not only animals that can feel the wrath of C. botulinum, explains Dr Sebaihia: “The soil can be a harsh environment and food can be scarce. To see off the competition, C. botulinum comes with its own ‘antibiotic’ — a chemical called boticin that kills competing bacteria.”

Genome sequences can tell us a lot about the biology of the organism, but research into clostridia has been hampered by the lack of a good genetic system. Professor Nigel Minton, Professor of Applied Molecular Microbiology at The University of Nottingham, has developed new methods to knock out genes in clostridia.

“Even after decades of research, only a handful of mutants had been made in clostridia, and none in C. botulinum,” Professor Minton explains. “We have developed a highly efficient system, the ClosTron, with which we have, in a few months, knocked out over 30 genes in four different clostridial species, including eight in C. botulinum. The availability of this tool should revolutionise functional genomic studies in clostridia.”

This remarkable, stable genome demonstrates the wide range of strategies used by bacteria to enhance their chances of survival. For the Clostridia, these range from the approach used by Cdiff — long-term interaction with hosts, which involves evading the immune system and countering antibiotics — to the single-minded opportunistic approach of C. botulinum.

Emma Thorne | alfa
Further information:
http://www.nottingham.ac.uk

Further reports about: Botulinum Clostridium Soil Toxin clostridia

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

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

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>