Viruses are capable of outmanoeuvring the ability of bacteria to commit 'suicide,' new research shows

Nov 12, 2012

(Phys.org)—In an extraordinary example of altruistic behaviour, bacteria are capable of giving up their lives rather than allowing a viral infection to spread through their population. Now, new research has shown that viruses have evolved a mechanism that blocks bacteria from killing themselves.

The viral evasion process has been discovered in a strain of the potato soft rot and blackleg bacterium Pectobacterium atrosepticum by Professor George Salmond at the University of Cambridge's Department of Biochemistry and researchers at the University of Otago, New Zealand, and was published on 18 October in the journal .

commit altruistic suicide by producing a lethal toxin within their cells after being infected by certain viral parasites, known as bacteriophages. The new study has shown that bacteriophage mutants have evolved that can suppress the toxin.

These rare mutants produce an antitoxin made of the genetic material RNA. Because the antitoxin is similar to an normally manufactured by the bacteria, it prevents the toxin from completing its lethal function, and the virus can continue replicating without becoming a victim of the host's defensive system.

"This work highlights the incredibly dynamic world of adaptive co-evolution in bacteria and their viruses," said Professor Salmond, whose research was funded by the BBSRC. "The emergence of an RNA-based in the virus to suppress bacterial suicide is an exciting observation."

The mutant bacteriophage is also able to transfer DNA encoding the defence system to a new bacterial host. In doing so, it may indirectly create populations of host cells inside which it can successfully replicate, while potentially providing the new host with better protection from competing viral predators.

"Multiple alternative and novel routes, through which different bacteriophages may evolve to evade abortive infection, remain to be discovered," added Salmond. "Because the bacteriophage investigated can pick up DNA from one bacterium and transfer it to a new host, this meant that escape mutants might be able to transfer the abortive infection system to other hosts – and that was confirmed. In effect, this could be viewed as an example of 'infectious altruism' – with a virus acting as a vector to transmit an antiviral defence system between bacteria."

Explore further: Fighting bacteria—with viruses

Related Stories

When viruses infect bacteria

Jun 30, 2011

(PhysOrg.com) -- Viruses are the most abundant parasites on Earth. Well known viruses, such as the flu virus, attack human hosts, while viruses such as the tobacco mosaic virus infect plant hosts.

Turning bacteria against themselves

Feb 08, 2011

Bacteria often attack with toxins designed to hijack or even kill host cells. To avoid self-destruction, bacteria have ways of protecting themselves from their own toxins.

Understanding a bacterial immune system one step at a time

May 17, 2011

Researchers at the University of Alberta have taken an important step in understanding an immune system of bacteria, a finding that could have implications for medical care and both the pharmaceutical and dairy industries.

Using viruses to beat superbugs

Mar 26, 2012

Viruses that can target and destroy bacteria have the potential to be an effective strategy for tackling hard-to-treat bacterial infections. The development of such novel therapies is being accelerated in response to growing ...

Flu jab for bacteria

Mar 31, 2010

Viruses can wreak havoc on bacteria as well as humans and, just like us, bacteria have their own defence system in place, explains Professor John van der Oost, at the Society for General Microbiology's spring ...

Recommended for you

Fighting bacteria—with viruses

5 hours ago

Research published today in PLOS Pathogens reveals how viruses called bacteriophages destroy the bacterium Clostridium difficile (C. diff), which is becoming a serious problem in hospitals and healthcare institutes, due to its re ...

Atomic structure of key muscle component revealed

5 hours ago

Actin is the most abundant protein in the body, and when you look more closely at its fundamental role in life, it's easy to see why. It is the basis of most movement in the body, and all cells and components ...

Brand new technology detects probiotic organisms in food

Jul 23, 2014

In the food industr, ity is very important to ensure the quality and safety of products consumed by the population to improve their properties and reduce foodborne illness. Therefore, a team of Mexican researchers ...

Protein evolution follows a modular principle

Jul 23, 2014

Proteins impart shape and stability to cells, drive metabolic processes and transmit signals. To perform these manifold tasks, they fold into complex three-dimensional shapes. Scientists at the Max Planck ...

Report on viruses looks beyond disease

Jul 22, 2014

In contrast to their negative reputation as disease causing agents, some viruses can perform crucial biological and evolutionary functions that help to shape the world we live in today, according to a new report by the American ...

User comments : 0