Resistance held in animal genes

A new class of antibiotic resistance gene has been discovered by scientists in Scotland. It may help to explain why some bacteria are immune to medicines despite containing none of the previously discovered resistance genes.

Researchers at the Rowett Institute in Aberdeen have isolated the new class of antibiotic resistance gene in the gut of cattle, but they have also found an isolated case of the gene in a Japanese pig.

The scientists do not yet know whether the gene occurs naturally in the gut of cattle or whether it has come from the soil, cattle feed or medicines.

The researchers are about to start work to see if the gene, which is resistant to the all-purpose antibiotic tetracycline, is also found in other animals and in humans.

Antibiotic resistance is becoming a huge clinical problem as humans and animals build natural immunities. The immunities are thought to have developed as a result of animals' regular exposure to drugs that were added to cattle feed and are still used in veterinary medicines and then, possibly, to have passed to humans.

Antibiotic resistance is now being investigated by the House of Lords Science and Technology Committee.

According to Harry Flint, chief investigator on the project, the new antibiotic gene, which researchers have named tetv, is the first such discovery in several years and is "potentially very significant".

He said: "There won't be more than 15 classes of resistance gene known."