Hydrogen-powered invasion

December 11, 2013

The intestine is bustling with billions of intestinal bacteria that aid digestion and keep it healthy. A vast array of microorganisms (microbiota) colonise the intestine so densely that pathogens do not usually stand a chance of multiplying. However, some pathogens, such as the diarrhoea-causing bacterium Salmonella Typhimurium, still manage to invade this densely populated ecosystem. Researchers at ETH Zurich are a step closer to finding out how they do this trick and discovered where the pathogen obtains the energy from for its attack.

Wolf-Dietrich Hardt, Professor of Microbiology at ETH Zürich, together with his PhD student Lisa Maier, examined which factors play a role in the early stages of a Salmonella attack. During the invasion of the intestinal ecosystem, Salmonella Typhimurium uses an enzyme that helps it to assert itself against microbiota: the hydrogenase enzyme, which converts hydrogen into energy. "Although we already knew that Salmonella Typhimurium can use hydrogen in addition to many other sources of energy, it was not clear which source of energy it used during this early stage of intestinal colonisation," explains Maier.

Theft-based hydrogen economy

Hydrogen is created in the intestine as a chemical intermediate of the microbiota's normal metabolism. "Salmonella therefore operates a theft-based hydrogen economy by stealing energy from the microbiota to assert itself," says Hardt. Because the microbiota metabolism of most animals works in a similar way, the pathogen can find the necessary energy source for its initial attack in any new animal host.

Once Salmonella Typhimurium has managed to multiply inside the intestine, the bacterium invades the intestinal tissue and causes infection and diarrhoea. In some cases, Salmonella Typhimurium even finds its way into the bloodstream and internal organs. However, animal experiments have shown that the energy boost from hydrogen does not play an essential role during this process. "Outside the intestinal lumen, Salmonella Typhimurium does not have to create space for itself in a dense community of microorganisms," explains Maier.

The Achilles' heel of intestinal flora

The hydrogenase enzyme is also found in other bacteria, such as Escherichia coli and Helicobacter pylori, which causes stomach ulcers. The researchers therefore suspect that other pathogens also use the hydrogen produced by intestinal flora as a source of energy. This would make the microbiota's own metabolism an Achilles' heel in the defence against a range of germs.

"The purpose of intestinal flora is to protect against infection. However, we are now seeing for the first time that it can also facilitate infections by serving as an unintentional energy provider," says Hardt. The interaction between microbiota and pathogens is thus more complex than initially thought.

-end-
Further reading:

Maier L, Vyas R, Cordova CD, Lindsay H, Schmidt TSB, Brugiroux S, Periaswamy B, Bauer R, Sturm A, Schreiber F, von Mering C, Robinson MD, Stecher B, Hardt WD: Microbiota-Derived Hydrogen Fuels Salmonella Typhimurium Invasion of the Gut Ecosystem. Cell Host & Microbe, December 11, 2013. DOI: 10.1016/j.chom.2013.11.002

ETH Zurich

Related Hydrogen Articles from Brightsurf:

Solar hydrogen: let's consider the stability of photoelectrodes
As part of an international collaboration, a team at the HZB has examined the corrosion processes of high-quality BiVO4 photoelectrodes using different state-of-the-art characterisation methods.

Hydrogen vehicles might soon become the global norm
Roughly one billion cars and trucks zoom about the world's roadways.

Hydrogen economy with mass production of high-purity hydrogen from ammonia
The Korea Institute of Science and Technology (KIST) has made an announcement about the technology to extract high-purity hydrogen from ammonia and generate electric power in conjunction with a fuel cell developed by a team led by Young Suk Jo and Chang Won Yoon from the Center for Hydrogen and Fuel Cell Research.

Superconductivity: It's hydrogen's fault
Last summer, it was discovered that there are promising superconductors in a special class of materials, the so-called nickelates.

Hydrogen energy at the root of life
A team of international researchers in Germany, France and Japan is making progress on answering the question of the origin of life.

Hydrogen alarm for remote hydrogen leak detection
Tomsk Polytechnic University jointly with the University of Chemistry and Technology of Prague proposed new sensors based on widely available optical fiber to ensure accurate detection of hydrogen molecules in the air.

Preparing for the hydrogen economy
In a world first, University of Sydney researchers have found evidence of how hydrogen causes embrittlement of steels.

Hydrogen boride nanosheets: A promising material for hydrogen carrier
Researchers at Tokyo Institute of Technology, University of Tsukuba, and colleagues in Japan report a promising hydrogen carrier in the form of hydrogen boride nanosheets.

World's fastest hydrogen sensor could pave the way for clean hydrogen energy
Hydrogen is a clean and renewable energy carrier that can power vehicles, with water as the only emission.

Chemical hydrogen storage system
Hydrogen is a highly attractive, but also highly explosive energy carrier, which requires safe, lightweight and cheap storage as well as transportation systems.

Read More: Hydrogen News and Hydrogen Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.