Serum antibodies against particular antigens of Borrelia burgdorferi sensustricto and their potential in the diagnosis of canine Lyme borreliosis

Dog sera (n = 118) were tested for antibodies recognizing Borrelia (B.) bur gdorferi sensu stricto strain B31 (ATCC 35210) antigens. In total, 18 of th e dog sera gave positive results in a whole cell sonicate ELISA (WCS ELISA) . These positive sera were further evaluated by immunoblot assay, utilizing a whole bacterial lysate as antigens. 94.4 % (17 of 18) of the dog sera reacted with immunodominant antigens at 2 0-22 kDa (protein C, pC), 31 kDa (outer surface protein A, OspA), 34 kDa (o uter surface protein B, OspB), 41 kDa (flagellin), 60 kDa ("common antigen" ), and/or 100 kDa (presumably p100). Sera recognizing pC (20-22 kDa) and an tigens > 94 kDa always detected the highest number of antigen bands, indica ting the specificity of those antigens in serological diagnosis. The results clearly demonstrate that the WCS ELISA is a useful tool for tes ting sera of dogs for antibodies against B. burgdorferi. However, positive results should be confirmed by immunoblot, using WCS as antigen. According to the presented data, we recommend criteria for B. burgdorferi i mmunoblots using dog sera as follows: sera have to be considered as positiv e if they detect the 41 kDa flagellin, and two of the 5 immunodominant anti gens, namely > 94 kDa (presumably p100), 60 kDa ("common antigen"), 34 kDa and 29-31 kDa (OspB and OspA, respectively) and 20-22 kDa (pC). If sera onl y recognize the 41 kDa flagellin, this result is equivocal, requiring testi ng a second serum sample 4 to 8 weeks later.