Thaindian News

London, Feb 5 (IANS) In what was described as “a significant step” in malaria control, a team of international scientists Thursday said they have identified specific mosquito genes associated with resistance to a common class of insecticide. Malaria kills more than a million people every year - mostly children - but efforts to combat the scourge have been thwarted by the growing resistance of mosquitoes to insecticides.

With very few insecticides thought to be effective, cheap and safe for spraying at home, findings of genetic research published Thursday are expected to lead to the development of more effective preventive measures.

In research published online in Genome Research, an international team of scientists led by Dr Charles Wondji, a Wellcome Trust fellow at the Liverpool School of Tropical Medicine, has identified the genetic basis of resistance to common pyrethroid insecticides in the mosquito Anopheles Funestus, one of the major malarial vectors in Africa.

The group studied strains of mosquitoes that are susceptible to pyrethroids and others that are resistant, and narrowed down the potential genetic culprits to members of a family of genes coding for enzymes known as cytochrome P450s, Wellcome Trust said.

The P450s are common to all classes of organisms, and are considered a first line of defence against toxins. The researchers found two cytochrome P450 genes in that are associated with pyrethroid resistance.

Dr. Hilary Ranson of the Liverpool School of Tropical Medicine and a co-author of the study, said: “If the enzymes responsible for resistance are very similar in both species, there is a much greater incentive to invest efforts in identifying specific enzyme inhibitors in the knowledge that they are likely to be effective at overcoming resistance in both major malaria vectors.”

But she said it was critical that these mosquito P450 genes do not have close relatives in the human genome, so that “targets” developed against these mosquitoes have a low risk of toxicity in humans.