Figure 1.

Pulmonary granulomas fixed in buffered formalin and stained with hematoxylin and eosin (H&E) from a nonvaccinated (A and C) and bacillus Calmette-Guérin (BCG)-vaccinated (B) guinea pig. Primary lesions from nonvaccinated guinea pigs were characterized as large and necrotic (A), whereas secondary lesions from the same animals were small and non-necrotic (C). Primary granulomas from BCG-vaccinated guinea pigs were highly cellular, non-necrotic, and smaller than the primary granulomas found in the nonvaccinated group (B). Total magnification for A: ×100; for B and C: ×400.