Use of antibody and lectin-colloidal gold conjugates to detect surface and extracellular glycoproteins produced in vivo by the Lyme disease spirochete Borrelia bergdorferi

Despite the often serious pathological ramifications of Lyme disease, Borrelia burgdorferi, the causative agent, is rarely demonstrated in nor isolated from naturally-infected mammalian hosts. This dilemma has led to suggestions that a limited number of spirochetes expel extracellular bioproducts that may contribute to the clinical symptoms. Currently, no mammalian toxins have been attributed to B. burgdorferi, however, the production of extracellular vesicles by this bacterium was recently described. In order to assay the possible presence of such extracellular material in infected hosts, we developed a sensitive electron microscopic assay to detect and characterize B. burgdorferi products in biological samples. Polyclonal rabbit serum was raised against purified B. burgdorferi vesicles and against an electrophoretically-purified 83 kilodalton (kDa) vesicle-associated protein. After purification of IgG from the sera, anti-vesicle F(ab’)2 fragments were produced and used to “activate” parlodion-coated grids. Such grids were incubated with cultured spirochetes, or with fluids and tissues from infected and non-infected mammals and ticks. Captured antigens were then labeled with anti-83 kDa IgG and Protein A-colloidal gold conjugates, and/or lectin-colloidal gold conjugates, then examined and characterized by electron microscopy.