Fig. 2.

Pathological analysis of CA16-infected neonatal mice. One-day-old ICR mice were intracerebrally inoculated with medium or CA16CC024. No histological change was observed in the hind-limb muscle (a) or spine skeletal muscle (e) of the non-infected control mice. Infected mice (grades 4–5) exhibited severe necrosis, including muscle bundle fracture, dissolution of muscle fibre cells, nuclear shrinkage and swelling (b), and inflammatory cell infiltration (arrow) (c, d). Infected mice (grades 4–5) showed loose muscle fibres in the juxtaspinal skeletal muscle (f). No histological change was observed in the brains of the non-infected control mice (g) or CA16-infected mice (h). No histological changes were observed in the lungs of the non-infected control mice (i). Mice infected with CA16CC024 exhibited severe alveolar shrinkage (j), a few areas of scattered pulmonary fibrosis (k), a large number of red cells (j, arrow), and vascular dilatation and congestion (j) in the lung tissue. Magnification: a, b, e–j: ×400 (scale bars, 20 μm); c, d, k, l: ×2000. The results are representative of three independent experiments.