Figure 1. Painting of a man suffering from tetanus. (Charles Bell, Royal College of Surgeons in Edinburgh, with permission.)

Figure 2. Mycobacterium tuberculosis in bone-marrow macrophages of a mouse. The bacterial cells are approximately 0.4 µm in diameter and 1.2 µm long. (Micrograph: Volker Brinkmann and Stefan H.E. Kaufmann, Max-Planck-Institute for Infection Biology, Berlin, Germany.)

Figure 3. Model of T3S (Type III Secretion Systems). The apparatus is anchored in the bacterial cytoplasmic membrane. The “needle” of the apparatus penetrates the membrane of the animal cell. Effector molecules (EM) are released into the animal cell. (Drawing: Anne Kemmling, Goettingen, Germany.)

Figure 4. Uropathogenic strain 536 of E. coli on bladder epithelium. (Electron micrograph: Hilde Merkert, Wuerzburg, Germany.)

Figure 5. Imprint of a soybean leaf onto a methanol-containing agar medium. The imprint has been produced by pink-colored colonies of methylobacteria. (Photograph: Julia Vorholt, Zurich, Switzerland.)