FIG. 1.

Protein cocktail-induced skin test responses in cattle. Skin test responses were measured at 72, 96, and 120 h in cattle naturally exposed to M. bovis (n = 37). (A) Comparative SICCT PPD responses (PPD-B − PPD-A). (B) Responses induced by a protein cocktail of 10 μg each of ESAT-6, CFP-10, MPB70, and MPB83. The increase in skin induration for each animal is represented by open circles, and the horizontal line provides the mean (± standard error of the mean [SEM]), with results expressed as the difference in skin thicknesses (mm) between the pre- and post-skin test readings. The statistical difference between responses was determined by using ANOVA (*, P < 0.05; **, P < 0.01; ***, P < 0.001).