FIG 3.
Pathological analyses of CV-A6-infected newborn mice. One-day-old ICR mice were intracerebrally inoculated with Changchun046 (105.0 CCID50/ml), Changchun097 (104.0 CCID50/ml), Changchun099 (105.0 CCID50/ml), or Changchun098 (105.0 CCID50/ml) or medium (negative control). Infected mice with grade 4 or 5 that exhibited severe hind limb paralysis were dissected for H&E staining. Representative images from the hind limb muscle, spine muscle, cardiac muscle, and lung and intestine tissues after infection are shown. Hind limb muscle (B to D) and spine muscle (G to I) fibers exhibited severe necrosis, including muscle bundle fracture (black arrows), muscle fiber swelling (green arrows), nuclear dissolution (red arrows), and shrinkage (blue arrows), in Changchun046-, Changchun097-, and Changchun099-infected mice. No obvious changes were found in the hind limb muscle and spine muscle fibers of Changchun098-infected mice (E and J), and no detectable pathological changes were observed in the heart (L to O), lung (Q to T), or intestine (V to Y). Magnification, ×400 (scale bars, 20 μm). The results are representative of three independent experiments.