Interactions between Borrelia burgdorferi and mouse fibroblasts

Borrelia burgdorferi spirochetes are an infectious agent of Lyme borreliosis. The aim of our studies was to investigate the fate of engulfed B. burgdorferi cells in L-929 mouse fibroblasts and to observe development of intracellular infection in vitro after 2 and 48 h. Electron microscopic studies reveal consecutive stages of B. burgdorferi spirochetes penetration to mouse fibroblasts in vitro. It has been observed, as a first step attachment and engulfment of spirochetes followed by formation of vacuoles. After 48 hours of infection, vacuoles of fibroblastic cells have been seen full of B. burgdorferi bacteria and latter they have been released from infected cells to extracellular space. It can be the evidence that B. burgdorferi multiply intracellulary.