Listeria monocytogenes has a particular tropism for the central nervous system. To gain knowledge about the immune response elicited by L. monocytogenes in the brain, we used a rat ex-vivo organotypic nervous system culture as a model for Listeria infection. Brain sections were maintained several weeks alive to study the infection process.
Scanning electron microscopy reveals how brain phagocytic cells (called brain macrophages or “microglia”) are quickly recruited from deeper brain layers to the surface of the infected tissue. Picture shows the surface of the brain (asterisk), and a dead microglial cell fragmented into phagosomes of different sizes still filled with L. monocytogenes (arrowheads). New phagocitic cells arrive to engulf this dangerous cargo (arrows). Magnification: ×5.000. Scale bar: 20 um.
Credit: Ramos Vivas Jose
Sigma-Aldrich microbiology photography competition