Detection of Borrelia burgdorferi DNA by the polymerase chain reaction.

DNA amplification by the polymerase chain reaction (PCR) was used to detect DNA of the Lyme disease spirochaete Borrelia burgdorferi. Primers that specify the amplification of a 145 basepair DNA fragment of the OspA gene of B. burgdorferi were used. The amplification product was detected by gel electrophoresis and ethidium bromide staining or by hybridization to a radiolabelled oligonucleotide probe. The hybridization method was found to be more sensitive. As little as 50 fg of purified B. burgdorferi DNA could be detected by PCR. This corresponds to fewer than 50 spirochaetes. The specificity of PCR for B. burgdorferi was tested by using DNA from other organisms as templates for amplification. No cross-reactivity was found. The data shown provide useful information for the development of a PCR-based diagnostic test for Lyme disease.