Differentiation of Borrelia Microbes from Collagen Debris and Collagen Fibrils in Blood Cultures

Borrelia burgdorferi (B. burgdorferi) causes Lyme disease after being deposited in the skin by Ixodes ticks. A characteristic rash may appear and be accompanied by systemic symptoms such as fatigue, fever, headache, arthralgias or myalgias [1-4]. In order to establish itself in the body and/or migrate to organs, the spirochete must interact with cells of the connective tissue and adhere to or colonize in the presence of macrophages, dendritic cells, fibroblasts, and the associated extracellular matrix (ECM) [5,6]. Some Borrelia surface proteins involved in the process of adherence to host ECM include a fibronectin receptor [7], proteins that bind to glycosaminoglycans (GAGs) [8-10] and membrane lipoproteins that bind decorin [11-15]. Multiple modes of interaction with the ECM help to explain the ability of the organism to survive, migrate, and thrive in many organs of the body [2,11,16,]. The ECM of the dermis is one of the first tissues encountered by Borrelia. The dermis is composed of protein and polysaccharide but is particularly rich in Type I collagen. The organism must make its way from the dermis into the bloodstream and from the blood into connective tissue of the organs. Two major candidates for adherence to and migration through the body include decorin and collagen [13,15,17-20]. Studies have shown that Borrelia can bind to lattices prepared from acetic-acid extracted Type I collagen devoid of decorin and other proteoglycans. B. burgdorferi invaded and colonized these lattices [1].