Fig. 2
Immunohistochemistry detection of L. monocytogenes in mammary tissue. Nuclei are counterstained in blue with hematoxylin. a Positive reactions are indicated with arrows corresponding to different tissue locations: inside the mammary alveolus and in intra-alveolar neutrophils (red arrows); in tissue macrophages (yellow arrows), and in alveolar epithelial cells (green arrows. b Higher magnification showing a detail with positive macrophages (yellow arrows) and epithelial cells (green arrows). c positive signals in epithelial cells of a morphologically intact mammary alveolus (green arrows). A positive tissue macrophage can also be seen (yellow arrow)