Authors: Anna Goc, Aleksandra Niedzwiecki, Matthias Rath
Presented at: ASM Microbe 2016; June 16–20, 2016 | Boston, MA
Published in: ASM Microbe 2016 Final Program and as a press release; Poster # SATURDAY-441
Background: Little is known about the anti-borrelieae activity of vitamins with commercially available agents against spirochetes of Borrelia sp. that cause Lyme disease. To better understand such cooperation, we studied the anti-bacterial efficacy of vitamin D3 and vitamin C (known for their antimicrobial activity) with doxycycline (one of the most frequently prescribed drugs for Lyme patients) against Borrelia sp. Methods: Doxycycline was tested in combination with vitamin D3, and with vitamin C for their in vitro effectiveness against vegetative (spirochetes) and dormant (rounded bodies, biofilm) forms of Borrelia burgdorferi and Borrelia garinii using dark field and fluorescence microscope. Synergistic antibacterial effect of these agents was evaluated at their MIC values and three dilutions above (2-6 X MIC) as well as three dilutions below their MICs (1/2-1/8 X MIC), according to checkerboard assays, and defined by fractional inhibitory concentration index. Additionally, a Student t-test statistical analysis was performed for further validation. All experiments were performed in triplicates. Results: The results showed that doxycycline in combination with vitamin D3 exhibits synergistic anti-spirochetal and amended anti-biofilm effects, whereas with vitamin C synergistic anti-spirochetal and additive anti-rounded bodies’ effect was observed. Although complete elimination of rounded forms and mature biofilm was not noted, tested combinations of agents greatly reduced viable organisms in term of qualitative effect. Conclusions: The data obtained from this in vitro study revealed that doxycycline in combination with vitamin D3 and vitamin C expresses compelling antibacterial action against examined species of Borrelia. This indicates that a commercially and widely used drug doxycycline may act with vitamins D3 and C and that these vitamins may serve as an important addition to treatment of Lyme disease bacteria.
Press release by ASM Microbe 2016: