False-colour transmission electron micrograph of Neisseria meningitidis, spherical bacteria which cause meningitis in humans. The bacteria are typically seen in pairs, each one concave on the side facing its partner. They are surrounded here by extracellular blebs. Meningitis is an inflammation of the meninges, the membranes enclosing the brain and spinal cord. Symptoms include intense headache, fever, loss of appetite, intolerance of light & sound, muscle rigidity and, in severe cases, convulsions, vomiting & delirium leading to death. Bacterial meningitis is treated with antibiotics or sulphonamides. Magnification: x50,800 at 7x8 inch, x16,900 at 6x7cm size.