TABLE 2.
Histopathological grading system for livers and spleens of mice infected with various S. enterica serovar Typhimurium
| Organ | Score | Description |
|---|---|---|
| Liver | 0 | Normal histology |
| + | Occasional portal, lobular, and perivascular histiocytic infiltrates; no evidence of necrosis | |
| ++ | Focal necrosis of hepatocytes with infiltration by macrophages and PMNs; histiocytic infiltrates observed focally and perivascularly | |
| +++ | Diffused histiocytic infiltrates in lobules and perivascular areas; focal necrosis of hepatocytes with PMNs and macrophages infiltrating necrotic areas | |
| ++++ | Diffused histiocytic infiltrates accompanied by areas of necrosis that are more extensive | |
| Spleen | 0 | Normal histology |
| + | Scattered macrophages infiltrating marginal zone; lymphoid follicles slightly increased in size, with preservation of their outlines; scattered immunoblasts and apoptotic lymphocytes observed in the lymphoid follicles | |
| ++ | Moderate architectural disruption of lymphoid follicles by macrophages infiltrating red pulp and marginal zone; moderate expansion of immunoblasts and apoptotic bodies | |
| +++ | Severe disruption of lymphoid follicles with marked infiltration of marginal zone and red pulp by sheets of macrophages; abundant immunoblasts and apoptotic bodies in follicles |