The urinary bladder, a consistent source of Borrelia burgdorferi in experimentally infected white-footed mice (Peromyscus leucopus).

White-footed mice, Peromyscus leucopus, were experimentally infected in the laboratory with Borrelia burgdorferi, the causative agent of Lyme disease. After mice were infected by intraperitoneal or subcutaneous inoculation or by tick bite, attempts were made to culture spirochetes from the urinary bladder, spleen, kidney, blood, and urine. Spirochetes were most frequently isolated from the bladder (94%), followed by the kidney (75%), spleen (61%), and blood (13%). No spirochetes were isolated from the urine. Tissue sectioning and immunofluorescence staining of the urinary bladder demonstrated spirochetes within the bladder wall. The results demonstrate that cultivation of the urinary bladder is very effective at isolating B. burgdorferi from experimentally infected white-footed mice and that culturing this organ may be productive when surveying wild rodents for infection with this spirochete.