Reactivity of dog sera to whole-cell or recombinant antigens of Borrelia burgdorferi by ELISA and immunoblot analysis

Enzyme-linked immunosorbent assays (ELISAs) with separate preparations of 1 0 purified recombinant antigens of Borrelia burgdorferi sensu stricto were used to test sera from 36 dogs not vaccinated with whole cells of this agen t and from five dogs vaccinated with whole-cell B. burgdorferi bacteria. Al l dogs lived in tick-infested areas of Connecticut and south-eastern New Yo rk state, USA. The non-vaccinated dogs had limb or joint disorder, lameness and fever during the period 1984-1991 and had antibodies to B. burgdorferi , as determined by a polyvalent ELISA with whole-cell antigen. In reanalyse s of sera for total immunoglobulins in ELISAs with recombinant antigens, re actions were most frequently recorded when outer-surface protein (Osp) F, p rotein (p)35, p37, p39 and p-41G (a flagellin component) were tested separa tely. Western immunoblots of a subset of 16 sera, positive by ELISA with wh ole-cell antigen and representing a range of antibody titres (640-40960), v erified immune responses to these or other lysed whole-cell antigens. Sera from vaccinated dogs contained antibodies to OspA, OspB, p22, p37 and p41-G . Therefore, serological reactions to OspF, p35 and p39 were the most impor tant indicators of natural exposure to B. burgdorferi. Serum reactivities t o these recombinant antigens in ELISAs can be used to help identify possibl e natural infections of canine borreliosis in dogs not vaccinated with whol e-cell B. burgdorferi and to provide information on the geographic distribu tion of this bacterium.