FIG 3.

Virulence assay of P-0 and P-200 in BALB/c mice. (A) Female animals were inoculated with either P-0 or P-200, and the footpad thickness was measured every week. (B) Twelve weeks later, the animals inoculated with P-200 were challenged with P-0. As a control, a naive group of animals of the same age were inoculated with P-0. (C) Histological findings in a footpad biopsy specimen from a mouse inoculated with P-200 and reinoculated with P-0, showing polymorphonuclear leukocytes destroying the Nocardia granules.