Multiple antigen target approach using the Accuplex4 BioCD system to detect Borrelia burgdorferi antibodies in experimentally infected and vaccinated dogs.

The primary objective of our study was to optimize detection of serum antibodies to Borrelia burgdorferi using a new commercial automated fluorescence system (Accuplex4 BioCD system， Antech Diagnostics， Lake Success， New York). The system used multiple natural and artificial peptides-outer surface proteins (OspA， OspC， OspF)， an outer membrane protein (P39)， and a proprietary synthetic peptide (small Lyme peptide [SLP])-and the results were compared with a commercially available enzyme-linked immunosorbent assay that uses a proprietary peptide (C6). Sera from 4 groups were evaluated: dogs vaccinated with 1 of 3 commercially available vaccines (n = 18); dogs infested with adult Ixodes scapularis (black-legged tick; n = 18); dogs previously vaccinated and then infested with I. scapularis (n = 18); and dogs with B. burgdorferi infection that were then vaccinated (n = 14). All of the vaccines evaluated induced OspA responses. However， antibodies against OspF or C6 were not induced in any of the vaccinated dogs. Additionally， the OspF antibodies had 100% sensitivity and specificity when compared to antibodies against C6 peptide. In B. burgdorferi-infected dogs， antibodies against OspC and SLP were detected in serum sooner than antibodies against the other targets. Low levels of antibodies against OspA developed in 6 of 14 B. burgdorferi-infected， unvaccinated dogs and had the shortest duration compared to the other antibodies. Detection of antibody responses to multiple B. burgdorferi targets with this system can be used to help differentiate vaccinated dogs from exposed dogs as well as acute infection from chronic infection.