11 February 2000

Gene research seeking better worm weapons

NEW parasite research, funded by the Wellcome Trust, will help sheep producers combat parasite infections more effectively.

Research will concentrate on genetics to tackle two types of nematodes: Teladorsagia circumcincta – small brown stomach worm, and Haemonchus contortus – barbers pole worm.

The Trust is committing £795,500 to the research, says a spokesperson. "Nematodes have increasing resistance to drugs. This research aims to make sure both agriculture and veterinary pharmaceutical industries have a wide armoury of products to target them."

Increasing resistance to wormers has stimulated the search for a vaccine, says nematode research leader at University of Edinburgh, Mark Blaxter. But he says research will concentrate on comparing the genomes of parasites, which will give clues on controlling them in different stages in their life cycles.

This will also help researchers find out which drugs and vaccines are most effective. Research will be carried out at Edinburgh and the Sanger Centre, near Cambridge.

"There is significant resistance in Australia and South Africa to ivermectin wormers. It is only a matter of time before this affects UK sheep populations in the same way," says Dr Blaxter.

Both worms are common parasites in UK, especially T circumcincta which is the main cause of parasitic gastro-enteritis in lambs, says VLA Weybridges Mike Taylor.

"It poses its biggest threat in late summer and autumn, causing weight loss, diarrhoea and in some cases death." &#42