Scientists reveal how river blindness worm thrives

Scientists at the University of Liverpool have found that the worm which causes River Blindness survives by using a bacterium to provide energy, as well as help 'trick' the body's immune system into thinking it is fighting a different kind of infection.

River Blindness affects 37 million people, mainly in sub-Saharan Africa, causing intense itching of the skin, and in severe cases, irreversible blindness. It is caused by a that is transmitted by blood-feeding blackflies, which breed in fast-flowing rivers.

The team at Liverpool investigated a bacteria carried by the worm, called Wolbachia, which if removed by antibiotics, kills the adult worm and cures River Blindness. To understand why the worms need these bacteria to survive, scientists sequenced the genome of Wolbachia from a closely related parasite in cattle.

They found that the bacteria could provide the worm with energy through a process that needs iron and oxygen, similar to cell energy processes in the human body. The bacteria can also 'trick' the body's immune response into believing it is dealing with a bacterial rather than , making it difficult for the body to fight the disease.

Research findings could help target drugs at disabling the bacteria's energy-giving properties, which may provide shorter for River Blindness. Understanding the bacteria's ability to misdirect the human immune response could also contribute to work into .

Dr Ben Makepeace, from the University of Liverpool's Institute of Infection and Global Health, said: " is a major problem in of Africa, where a similar parasite can also be found in cattle. Antibiotics have shown promise in critical trials, but treatment can be a long process for a patient, and so it is important for us to find new ways of combating the disease to improve patient welfare.

"It was a team at Liverpool that first discovered antibiotics could kill the bacteria inside these particular worms. The findings led us to believe that the bacteria played a crucial role in keeping the parasite alive. Sequencing the genome revealed that it could give the worm energy to survive and help 'fool' the host's immune response into believing it had to tackle a bacterial infection.

"We also studied, for the first time, which bacterial genes were switched on and off in different parts of the worm, and identified the kinds of proteins made by Wolbachia. We hope our research will contribute to shorter treatment programmes and potentially impact on the search for a vaccine."

More information: The study is published in the journal, Genome Research.

Related Stories

Study sheds new light on river blindness parasite

Jan 12, 2011

The team found that a bacterium inside the worm acts as a 'disguise' for the parasite, resulting in the immune system reacting to it in an ineffective way. The bacteria protect the worm from the body's natural defences, ...

Scientists identify most proteins made by parasitic worm

May 23, 2011

A team led by Thomas B. Nutman, M.D., of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, has completed a large-scale analysis of most of the proteins produced ...

New drug resistance found in river blindness

Jun 15, 2007

A 20-year effort to control the spread of onchocerciasis, or river blindness, in African communities is threatened by the development of drug resistance in the parasite that causes the disease, a study by McGill University ...

How the parasitic worm has turned

Jun 14, 2010

(PhysOrg.com) -- Parasites in the gut such as whipworm have an essential role in developing a healthy immune system, University of Manchester scientists have found.

Researchers unlock how key drug kills tropical parasites

Nov 10, 2010

In a major breakthrough that comes after decades of research and nearly half a billion treatments in humans, scientists have finally unlocked how a key anti-parasitic drug kills the worms brought on by the ...

Recommended for you

Mysterious esophagus disease is autoimmune after all

23 hours ago

(Medical Xpress)—Achalasia is a rare disease – it affects 1 in 100,000 people – characterized by a loss of nerve cells in the esophageal wall. While its cause remains unknown, a new study by a team of researchers at ...

Diagnostic criteria for Christianson Syndrome

Jul 21, 2014

Because the severe autism-like condition Christianson Syndrome was only first reported in 1999 and some symptoms take more than a decade to appear, families and doctors urgently need fundamental information ...

User comments