Lyme Disease Spirochetes Tracked in 3D

Pathogenic spirochetes are a group of bacteria that cause a number of emerging and re-emerging diseases worldwide, including syphilis, leptospirosis, relapsing fever, and Lyme disease. The mechanism by which they disseminate from the blood to target sites is unknown. Direct visualization of these bacteria may yield critical insight into resultant disease processes.

The team therefore set out to directly observe these bacteria at the single-cell level in a living host, using an engineered fluorescent strain of B. burgdorferi as an example bacterium. Using conventional and spinning disk confocal microscopy, the investigators were able to track the movement of the bacteria and the interaction of the bacteria with the vascular wall in mice. They found that vascular escape is a multi-stage process and that spirochete movement appears to play an integral role in dissemination from the blood to target tissue sites.

This use of high-resolution, 3D imaging to visualize the dissemination of a bacterial pathogen in vivo lays the groundwork for a better understanding of the mechanisms by which these and other bacteria disseminate throughout the body to cause disease.