Lyme disease lingers after antibiotics, study shows

DAVIS, CALIF. — The bacteria that cause Lyme disease reside in mouse tissue after a full round of antibiotic treatment, University of California-Davis (UC-Davis) researchers report.

Scientists are not suggesting that its continued presence represents chronic disease or supports the extended use of antibiotics. However, the findings set the stage for controlled laboratory research investigating potential therapies for persistent infections, experts say.

The study appears in last month's issue of Antimicrobial Agents and Chomotherapy.

"Lyme disease is a tough nut to crack," says lead researcher Stephen Barthold, DVM, PhD, in a university news release. "The bacterium Borrelia burgdorferi has evolved to evade the body's immune system, so it's not surprising that it can also evade antibiotics."

Barthold is director of UC-Davis' Center for Comparative Medicine, a cooperative research center in the schools of Medicine and Veterinary Medicine that investigates animal models of human disease.

"It's important to note that the numbers of residual bacteria identified in this study were very low and there was no evidence that they were causing inflammation," Barthold says. "Their presence shouldn't be misconstrued as a sign of chronic disease."