In an all-out effort to learn how to defeat resistance in lice, scientists at the University of Massachusetts say they are the first to come up with a way to actually grow colonies of mutated lice in their laboratory for closer study. Kyong Yoon, a Ph.D. student at the University of Massachusetts at Amherst, described the work to scientists attending the 224th national meeting of the American Chemical Society, the world's largest scientific society.
The most common ingredient in various products used to treat head lice is permethrin, an insecticide derived from natural compounds in chrysanthemum flowers, according to John Clark, Ph.D., a professor in the university's department of entomology and Yoon's faculty advisor.
The researchers hope their work will lead to new ways to control head lice.
In limited sampling studies of people in various parts of the United States, resistance to permethrin has ranged from 50 percent in some Los Angeles school children to about 98 percent in a migrant workers' camp in Florida, Clark noted during a telephone interview. Clark's research group also did sampling in Texas where resistance was found to be 75-80 percent. His group is aware of resistance in Boston and western Massachusetts although they have not yet measured the level of resistance, he added.
Clark and Yoon are the first researchers to develop an artificial feeding system that allows them to raise their own mutant lice for study.
"Our work is the first report of artificially rearing human head lice and carrying out a molecular linkage study in U.S. populations," according to Clark.
"We have a mem