[CanLyme note: The researchers acknowledge in their paper that their findings are limited to doxycycline, alone, at their prescribed dosages. The paper adds to the long list of articles that substantiate chronic persistent Lyme Disease beyond short term antibiotics and continued benefit while antibiotics are present.]
John R. Caskey, Monica E. Embers
Doxycycline is a commonly used antibiotic to treat Lyme disease and other bacterial infections. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for Borrelia burgdorferi have been investigated by different groups, but are experimentally established here as a function of input cell density. We demonstrate that B. burgdorferi treated in the stationary phase have a higher probability of regrowth following removal of antibiotic. In addition, we determine experimentally and mathematically that the spirochetes which persist post-treatment do not have a longer lag phase, but exhibit a slower growth rate than untreated spirochetes. Finally, we demonstrate that treating the spirochetes by pulse-dosing was not found to eliminate growth or reduce the persister population in vitro. From these data, we propose that B. burgdorferipersister development is stochastic and driven by slowed growth.