Putting a squeeze on Lyme disease

The Centers for Disease Control and Prevention recently reported that the incidence of Lyme disease, caused by the tick-borne bacterium Borrelia burgdorferi, has more than doubled in the past 15 years, with most cases concentrated in New England. Now, Yale scientists have found a loophole in the bacterium’s life cycle that offers a way to stop ticks from ever carrying the disease, which they pick up as larvae when they suck blood from mice.

Erol Fikrig, M.D., professor of medicine, epidemiology and microbial pathogenesis, and colleagues discovered that B. burgdorferi takes advantage of a protein that ticks inject into mice when they bite to prevent an immune response and swelling. When the researchers blocked this protein, either by stopping ticks from producing it in their salivary glands, or by coaxing the mice to obstruct it, the B. burgdorferi couldn’t go from mouse to tick.

The findings, published in the inaugural issue of Cell Host & Microbe in July, may eventually help curb infections in humans by targeting the bacterium at this early stage in its lifecycle. “You could reduce the number of ticks carrying Lyme disease,” says Fikrig. “That’s the long-term goal.”