FIG 7.

The pathogenicity of C. burnetii decreased in Rab11a^−/− CKO mice. (A) Mock-infected mice, WT C. burnetii-infected C57BL/6J WT mice, or Rab11a^−/− CKO mice were sacrificed at 14 days postinfection. The spleens of the mice were removed and photographed after bloodletting. (B) The ratio of spleen weight to body weight of each mouse was calculated. (C and D) The spleens (C) or lungs (D) of the WT or Rab11a^−/− CKO mice were ground, and the genome copies of C. burnetii were determined by qPCR. The data are presented as the mean of n = 8 mice per group, and the standard error is indicated by the error bar. (E) The lungs of mice were fixed in formalin, and the pathological lesions were observed in hematoxylin and eosin (H&E)-stained sections under a light microscope. Chronic lymphocyte infiltration around the bronchi (arrow a), chronic lymphocyte infiltration around blood vessels (arrow b), and plasmacytes (arrow c) were observed in the lungs of mice (magnification, ×400; bar, 100 μm).