An OspA antigen-capture enzyme-linked immunosorbent assay for detecting North American isolates of Borrelia burgdorferi in larval and nymphal Ixodes dammini

An antigen-capture enzyme-linked immunosorbent assay (ELISA) was developed for detecting North American isolates of Borrelia burgdorferi in larval, nymphal, and adult ticks. The assay uses an anti-OspA monoclonal antibody (H5332) for antigen capture and biotin-labelled polyclonal sera with streptavidin-horseradish peroxidase for signal generation. The assay recognized 15 of 15 North American B. burgdorferi isolates and did not cross- react with spirochete antigens of Borrelia hermsii, Borrelia turicatae, Borrelia coriaceae, or Borrelia parkeri, or with tick antigens of Ixodes dammini, Ixodes scapularis, Ixodes pacificus, Ixodes cookei, Ixodes angustus, or Ambylomma americanum. The assay, with a sensitivity of less than 150 spirochetes, can detect infections in larval, nymphal, and adult ticks. In addition to fresh ticks, B. burgdorferi infections in ticks stored frozen, dried, or in 70% ethanol can be determined with the assay.