Figure 7.

ArsR2 is crucial for B. abortus virulence. (A) The spleen weight of BALB/c mice infected with B. abortus or derivatives at one and four weeks post-infection. Data represent mean and standard deviation. *<0.05 by one-way analysis of variation followed by Tukey’s multiple-comparison test. (B) CFU of B. abortus and derivatives in spleens of infected mice at weeks one and four post-infection. Data represent mean and standard deviation. *<0.05 by one-way analysis of variation followed by Tukey’s multiple-comparison test. (C) Immunohistochemical staining for B. abortus in spleen sections of BALB/c mice infected with B. abortus or derivatives at four weeks post-infection. Arrows indicate examples of clusters of positive-stained cells. Scale bar represents 50 μm. (D) Representative micrographs of spleen histopathology at three weeks post-infection. Scale bar represents 50 μm. W, white pulp.