Fig 1.

Multiplex antibody values (MFI) to six surface antigens of B. burgdorferi in serum samples of experimentally infected dogs. Dogs were divided into three groups with four dogs per group: a noninfected control group and two infected groups exposed to 25 or 50 ticks, respectively. Serum samples were obtained on day 13 prior to tick exposure (d-13) and on days 21, 35, 49, 63, 77, and 92 postexposure. All sera were analyzed in a multiplex assay to simultaneously measure antibodies to six surface antigens of B. burgdorferi (A to F). The graphs show the mean values and standard errors for each time point and group of dogs. The dotted lines indicated the positive cutoff values for individual markers. The arrow shows the time of exposure to infected ticks. Asterisks indicate significant differences in antibody values between the 25- and 50-tick exposure groups: *, P < 0.05; **, P < 0.01; and ***, P < 0.001.