Two genes identified in Anopheles funestus mosquitoes are associated with resistance to the insecticide pyrethroid, which is used for malaria interventions such as indoor insecticide spraying or insecticide-treated nets, according to a study published Thursday in the journal Genome Research.
According to Reuters, the study’s findings could lead to the development of new malaria interventions featuring more effective insecticides that are less harmful to humans.
For the study, researchers from the Liverpool School of Tropical Medicine studied one group of A. funestus mosquitoes that were susceptible to insecticides and another group that was resistant. The researchers linked a family of genes, known as P450, to the presence of insecticide resistance among the mosquitoes. According to the researchers, the P450 gene family also is associated with insecticide resistance among other malaria vectors, suggesting that a targeted insecticide could play a major role in controlling the disease. In addition, the study found that humans do not carry the P450 gene, which could allow scientists to develop compounds that kill mosquitoes but do not harm people, the researchers said. According to Charles Wondji, one of the study researchers, it is challenging to find low-cost, effective insecticides that kill mosquitoes but are not toxic to humans.
Wondji said that the team "expected to find that different species and populations would have different groups of genes responsible" for insecticide resistance. However, the similarity of the genes was "encouraging news because it means that work to overcome resistance in one species is likely to be effective against the other," Wondji said (Kahn, Reuters, 2/4). Jo Lines, a researcher for the study, said there is a "good chance" that the same genetic variations are present in A. gambiae mosquitoes, which is a major malaria vector in Africa. He added that the study represents "the first case in which we have been able to pin these genes down definitely."
According to BBC News, the study’s findings could allow scientists to conduct simple genetic tests to determine insecticide resistance levels in a particular area. Current tests are time-consuming, and therefore the development of rapid tests is "very important work" that "would allow a far simpler and quicker test to be carried out," Lines said. Hilary Ranson, a lead author of the study, said the identification of these genes "will provide early warning of future control problems due to insecticide resistance and should greatly enhance our ability to mitigate the potentially devastating effects of resistance on malaria control"