Figure 1From: From cat scratch disease to endocarditis, the possible natural history of Bartonella henselaeinfection Valve of our patient with B. henselae endocarditis. Resected valve with B. henselae infection showing large and non-inflammatory vegetation on the valvular surface (A, hematoxylin-eosin, original magnification × 100). The diagnosis of vegetation was made by the presence of fibrinous material with numerous darkly stained bacilli (arrows in Figure 1B) consistent with Bartonella, organized in numerous clusters (B, Warthin-Starry silver staining, original magnification × 400). The bacteria (arrows in Figure 1C) are detected by immunohistochemical analysis in an extracellular location inside the valvular vegetation (C, polyclonal antibody anti-B. henselae with hematoxylin counterstain, original magnification × 200). Resected lymph node showed a necrotizing lymphadenitis. Numerous microabscesses composed of fragmented neutrophils were observed in homogenous necrotic areas. Necrotic regions were surrounded by a ring of macrophages and epithelioid histiocytes to form stellate inflammatory granulomas consistent with cat-scratch disease (D, hematoxylin-eosin, original magnification × 100).Back to article page