Identification of novel activity against Borrelia burgdorferi persisters using an FDA approved drug library.
Level 5 - mechanism / opinion, no new human data
In vitro bench study with no human or animal clinical data.
PubMed 26038747 · doi:10.1038/emi.2014.53
What was done
Researchers screened a library of 1,524 FDA-approved drugs against stationary-phase *Borrelia burgdorferi* in vitro using a SYBR Green I/propidium iodide viability assay to identify candidates capable of eradicating antibiotic-tolerant persister forms that survive doxycycline or amoxicillin.
What was found
The screen identified 165 compounds with greater activity against stationary-phase *B. burgdorferi* than doxycycline and amoxicillin. Further testing confirmed 27 top candidates with superior anti-persister activity. The most active agents included daptomycin, clofazimine, carbomycin, sulfa drugs (including sulfamethoxazole), and cephalosporins (such as cefoperazone). Highly active anti-persister agents like daptomycin and clofazimine showed relatively poor activity or high minimal inhibitory concentrations against actively growing *B. burgdorferi*. Quantitative clearance rates or concentrations were not provided in the abstract.
Why it matters
Standard frontline antibiotics for Lyme disease poorly clear stationary-phase persisters in vitro. Identifying existing approved medications with anti-persister activity provides potential candidate compounds for combination regimens.
Limits
The study is entirely in vitro, using stationary-phase culture as an operational model for persisters rather than an in vivo infection model. The abstract reports no numerical kill rates, concentrations, or statistical metrics. Whether stationary-phase *B. burgdorferi* persisters drive post-treatment Lyme disease syndrome in humans remains unproven, and in vivo efficacy and safety were not assessed.
Cited by
- supports Johns Hopkins researchers discovered that Lyme disease bacteria form biofilm persisters similar to tuberculosis and leprosy.