Alzheimer Plaques visualized by in situ DNA Hybridization with Molecular Beacons specific for Borrelia – a novel histomorphologic application

Background: This case describes a novel application of Molecular Beacons, which are a patented technology, for the detection of DNA in tissue sections from an infectious microbe, namely Borrelia burgdorferi, the etiologic agent of Lyme borreliosis. A 65-year-old man with Alzheimer’s disease and previously well documented spinal fluid neuroborreliosis eight years prior to death is the subject of this report. Neuroborreliosis in its tertiary from has been linked to some cases of Alzheimer’s disease (1. -4.) Findings: Molecular beacons designed from the flagellin b open reading frame (BBO 147) of Borrelia burgdorferi, strain B31 demonstrated positive fluorescein signals indicating successful probe hybridization with discrete 4 sharply demarcated rounded foci within tissue slides from autopsy hippocampus. Conclusions: Molecular beacons, carefully designed to hybridize only with the DNA of a target pathogen (after a comprehensive search of the entire human genome to confer probe specificity) are powerful molecular interrogators for evidence of tissue infection. The implications of the application are far reaching in the study of neurodegenerative diseases which might (like General Paresis and Tabes Dorsalis) be sequelae of chronic bacterial infection in the central nervous system.