Figure 3.

Challenge with the A. marginale strain UFMG2 in mice. Three-week-old female BALB/c mice were divided into three groups. One group received three immunization series of the hybrid MSP1a/OMP7/9 protein mixed with the ISA adjuvant (immunized group; N = 5). The second group (N = 5) received only the ISA adjuvant (Adjuvant group), and the third group (N = 5) received PBS (non-immunized group; N = 5). The mice were challenged with 3 × 10⁵ cells/mL of A. marginale UFMG2. The animals were observed for 42 days to measure weight loss, deaths, and signs, such as lethargy and ruffled and opaque fur (see Table 1). A Differences between related means of body weight followed for 42 days post-infection, the RM-ANOVA Test showed differences between the immunized and non-immunized mice showed differences between the immunized and non-immunized mice. The difference was evaluated by two-way RM ANOVA. The adjuvant group did not differ from either group (not shown). B The immunized group had 100% survival while 60% of non-immunized mice survived in Kaplan Meyer analysis. The adjuvant group did not differ from the immunized mice (not showing). C Morphological changes, such as cell destruction and pigmentation loss and featuring bacterial invasion in infected erythrocytes at 48 days post-infection. D Rickettsemia and A. marginale load and spherocytes counts were determined with blood smears stained with hematoxylin–eosin by optical microscopy [10].