Brussels, 03 Apr 2003
Scientists from the Netherlands have performed a simple laboratory experiment which could point to the origin of the killer pneumonia-like virus, dubbed SARS, which has so far infected 1,600 people worldwide.
SARS (severe acute respiratory syndrome) is believed by many to be a new type of coronavirus - a virus with an unusual ability to reshuffle genes and switch the type of host they can infect. The researchers from Utrecht University took a coronavirus lethal to cats and overnight, through the replacement of a single gene, it transformed into one that can infect mouse cells.
The result adds weight to the theory that the SARS virus may have originated from similar contact between human and animal viruses, resulting in a swapping of genes. Peter Rottier, lead scientist in the experiment, says: 'It's a very plausible explanation.'
The experiment was performed by taking samples of a lethal feline peritonitis virus and adding a gene fragment from a mouse coronavirus, which contains the coat protein that can identify and attack mouse cells. Within hours, some particles from the cat virus had exchanged their coat protein for the mouse one and were thus able to infect mouse cells.
This is a process that mirrors what could happen if the two viruses attacked the same cell simultaneously, and is one of the most likely explanations for the origins of the virus that has already killed more than 50 people.
This theory should be confirmed or disproved very shortly when scientists have pieced together the genetic sequence of the SARS virus, which was isolated at the end of March.
Lynn Enquist, editor of the Journal of Virology which published the team's work, concludes: 'The only way we'll ever understand these natural outbreaks is by first rate science and by getting it published.'