FIGURE 5.

Histopathological damage in hamsters infected with the invA⁻ mutant, invA^com revertant, and wild-type (WT) of L. interrogans strain Lai. Serious congestion and multiple focal necrosis of nephric tubular epithelia in kidney, evident hemorrhaging and inflammatory cell infiltration in lung, and extensive hepatocyte necrosis in liver occurred in hamsters infected with 10⁶ leptospires per animal of the invA^com revertant or the wild type. Conversely, mild cellular edema in kidney, inflammatory cell infiltration in lung, and slight granular degeneration in liver occurred in hamsters infected with the same number of the invA⁻ mutant.