title: Borrelia burgdorferi, the Causative Agent of Lyme Disease, Forms Drug-Tolerant Persister Cells.
abstract: Borrelia burgdorferi is the causative agent of Lyme disease, which affects an estimated 300,000 people annually in the United States. When treated early, the disease usually resolves, but when left untreated, it can result in symptoms such as arthritis and encephalopathy. Treatment of the late-stage disease may require multiple courses of antibiotic therapy. Given that antibiotic resistance has not been observed for B. burgdorferi, the reason for the recalcitrance of late-stage disease to antibiotics is unclear. In other chronic infections, the presence of drug-tolerant persisters has been linked to recalcitrance of the disease. In this study, we examined the ability of B. burgdorferi to form persisters. Killing growing cultures of B. burgdorferi with antibiotics used to treat the disease was distinctly biphasic, with a small subpopulation of surviving cells. Upon regrowth, these cells formed a new subpopulation of antibiotic-tolerant cells, indicating that these are persisters rather than resistant mutants. The level of persisters increased sharply as the culture transitioned from the exponential to stationary phase. Combinations of antibiotics did not improve killing. Daptomycin, a membrane-active bactericidal antibiotic, killed stationary-phase cells but not persisters. Mitomycin C, an anticancer agent that forms adducts with DNA, killed persisters and eradicated growing and stationary cultures of B. burgdorferi. Finally, we examined the ability of pulse dosing an antibiotic to eliminate persisters. After addition of ceftriaxone, the antibiotic was washed away, surviving persisters were allowed to resuscitate, and the antibiotic was added again. Four pulse doses of ceftriaxone killed persisters, eradicating all live bacteria in the culture.
authors.affiliation: Antimicrobial Discovery Center and Department of Biology, Northeastern University, Boston, Massachusetts, USA.
authors.forename: Bijaya
authors.initials: B
authors.lastname: Sharma
authors.affiliation: Antimicrobial Discovery Center and Department of Biology, Northeastern University, Boston, Massachusetts, USA.
authors.forename: Autumn V
authors.initials: AV
authors.lastname: Brown
authors.affiliation: Antimicrobial Discovery Center and Department of Biology, Northeastern University, Boston, Massachusetts, USA.
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Matluck
authors.affiliation: Department of Medicine, Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, Massachusetts, USA.
authors.forename: Linden T
authors.initials: LT
authors.lastname: Hu
authors.affiliation: Antimicrobial Discovery Center and Department of Biology, Northeastern University, Boston, Massachusetts, USA k.lewis@neu.edu.
authors.forename: Kim
authors.initials: K
authors.lastname: Lewis
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects; D025065:Borrelia burgdorferi / Q000187:drug effects*; D002443:Ceftriaxone / Q000627:therapeutic use; D017576:Daptomycin / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D006801:Humans; D008193:Lyme Disease / Q000188:drug therapy*; D008826:Microbial Sensitivity Tests / Q000379:methods; D016685:Mitomycin / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D016685:Mitomycin; D002443:Ceftriaxone; D017576:Daptomycin