Detection of Borrelia burgdorferi in tissues of experimentally infected Peromyscus leucopus by the polymerase chain reaction.

A polymerase chain reaction (PCR) assay was used to amplify a 158 base pair (bp) DNA fragment from the ospA locus of Borrelia burgdorferi. This assay could identify all of four distinct B. burgdorferi isolates from Oklahoma and could detect as little as 50 x 10(-15) g of purified DNA from B. burgdorferi (JD-1) after agarose gel electrophoresis and ethidium bromide staining. The assay was used to detect the Lyme spirochete in the heart, liver, spleen, kidney and urinary bladder of four experimentally infected Peromyscus leucopus and results were compared with detection by in vitro cultivation in BSK-II media. Fifteen of twenty organs examined showed 158 bp amplification products. Except for one kidney sample all organs that were culture-positive were also positive by PCR. Two culture-negative heart samples and one culture-negative liver sample were PCR positive. The results indicate that this PCR assay may be useful for detection of B. burgdorferi from field-caught wildlife hosts in epidemiological investigations.