Rapid differentiation of Borrelia garinii from Borrelia afzelii and Borrelia burgdorferi sensu stricto by LightCycler fluorescence melting curve analysis of a PCR product of the recA gene

To differentiate the Borrelia burgdorferi sensu late genospecies, LightCycl er real-time PCR was used for the fluorescence (SYBR Green I) melting curve analysis of borrelial recA gene PCR products. The specific melting tempera ture analyzed is a function of the GC/AT ratio, length, and nucleotide sequ ence of the amplified product. A total of 32 DNA samples were tested. Of th em three were isolated from. burgdorferi reference strains and 16 were isol ated from B. burgdorferi strains cultured from Ixodes ricinus ticks; 13 wer e directly isolated from nine human biopsy specimens and four I. ricinus ti ck midguts. The melting temperature of B. garinii was 2 degrees C lower tha n that of B. burgdorferi sensu stricto and B. afzelii. Melting curve analys is offers a rapid alternative for identification and detection of B. burgdo rferi sensu late genospecies.