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Current diagnostic tests for
Lyme disease (LD) are dependent upon the host serologic response and are insensitive early in infection and, possibly, following antibiotic therapy. We cloned a library of Borrelia burgdorferi 297 DNA and studied one clone, Ly-1, for its potential in diagnostic and pathogenic studies. Using pulsed-field electrophoresis, we demonstrated that Ly-1 is of chromosomal origin and estimated that the B. burgdorferi chromosome is approximately 1,100 kb in size. The 3.7-kb Ly-1 clone hybridizes with geographically diverse strains of B. burgdorferi. No cross hybridization occurs with DNA from human cells, Escherichia coli, Staphylococcus aureus, Clostridium difficile, or the closely related B. hermsii. We used a dot blot assay to detect 100 pg of B. burgdorferi DNA. We partially determined the nucleotide sequence of Ly-1 and used it to select and synthesize oligonucleotides for use in the polymerase chain reaction (PCR). Two different primer pairs were found to amplify DNA from nine geographically diverse isolates. We could detect 10 fg (less than 10 molecules) of B. burgdorferi or less than five spirochetes added to human urine. Finally, we were able to use the PCR to detect B. burgdorferi DNA in the urine of four of eight patients with suspected active LD (three with arthritis and one with neurologic manifestations), all of whom responded to antibiotic treatment. In contrast, those patients who were PCR negative either had inactive
disease or had been appropriately treated and did not respond to additional antibiotics, and all four control urine specimens were PCR negative. We conclude that B. burgdorferi DNA can be sensitively detected by the PCR with the primers and methods we describe and that the urinary tract is a site of persistent infection in some cases of human LD, an observation of potential diagnostic and pathogenic importance.