New Giant Virus Discovered by Scientists in France

Scientists in France have isolated a new giant virus that lurks inside amoeba and whose gene pool includes genetic material from other species.

The virus "is a completely new viral form," said Didier Raoult, head of infectious and emerging tropical disease research at Aix-Marseille 2 University in France.

About Dengue and Dengue Hemorrhagic Fever
Encyclopedia section of medindia gives general information about Dengue and Dengue Hemorrhagic Fever

The genome of the so-called Marseillevirus encompasses a complex repertoire of genes that are "very different from the DNA of other virus forms," and shows that there is genetic exchange between other micro-organisms such a giant viruses and bacteria found in amoeba, he told AFP in an interview.

Amoeba, single-cell life forms that can be parasites on either human or animals, are acting as "a sort of cradle of creation for new viruses and bacteria," Raoult said, whose research was also published this week by the Proceedings of National Academy of Sciences.

Only a small number of so-called giant viruses have been discovered, the first in 1993 by accident. Unlike classic viruses, they can been viewed through a conventional light microscope.

Mumps - Causes - Symptoms - Diagnosis And Treatment - FAQs
Mumps is a contagious viral infection that typically causes a painful swelling of one or more of the salivary gland. Mumps most commonly occurs in children aged 2-12 years who have not been vaccinated against the disease. However, it can occur at any age. It was a common childhood disease before the development of the mumps vaccine (MMR vaccine).

Even now little is known about them but in 2008, a team led by Raoult even found viruses that infect other viruses so as to replicate themselves, he said.

With a genome of 368,000 basic pairs, Marseillevirus is the fifth biggest virus ever sequenced and has a diametre of 250 nanometres (around 250 millionth of a millimetre, according the a report by Raoult's for the French National Centre for Scientific Research (CNRS).

'Darwinian Medicine: New Field of Medical Research in Focus at World Health Summit
A new field of medical research is viewing the emergence of modern epidemics like asthma and obesity through the prism of Charles Darwin's 150-year-old theory of evolution.

The DNA of the giant virus contains material from different sources including plant and animal matter, bacteria and other giant viruses such as the Mimivirus, the report said.

"There is a mechanism of permanent creation going on in amoeba producing a new repertoire of viruses and predisposing giant viruses to become pathogens once they specialise", Raoult said.

He said the mechanism was not foreseen by Charles Darwin's theory that life comes from a common ancestor.

"The idea of a common ancestor makes no sense in the light of viruses," he said.

"That was Darwin's idea, but he was clearly wrong."

Source-AFP
THK